JP2016093962A - Production method of optical film, optical film, and surface light-emitting body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method of an optical film showing excellent productivity and suppressing incorporation of air bubbles.SOLUTION: The production method of an optical film includes the following steps A to D to be successively carried out, in which a mixture B has a viscosity of 10 to 600 mPa s. In step A, a roll die 51 having an outer circumference surface where a plurality of concave microlens transfer portions are arranged is rotated, and the mixture B comprising an active energy ray-curable composition is applied on the outer circumference surface of the roll die while travelling a base material 17 along the outer circumference surface of the roll die and in the rotation direction of the roll die, so as to partially fill the microlens transfer portions with the mixture B. In step B, a mixture A comprising an active energy ray-curable composition is supplied between the outer circumference surface of the roll die and the base material. In step C, while at least the mixture A is held between the outer circumference surface of the roll die and the base material, a region between the outer circumference surface of the roll die and the base material is irradiated with active energy rays. In step D, a cured product obtained in step C is released from the roll die.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical film manufacturing method, an optical film, and a surface light emitter.

  Among surface light emitters, organic EL (electroluminescence) elements are expected to be used in next-generation lighting and flat panel displays that can replace fluorescent lamps and the like.

  The structure of the organic EL element is diversified from a simple structure in which an organic layer serving as a light emitting layer is sandwiched between two electrodes to a multilayered structure. Examples of the latter multilayered structure include a structure in which a hole transport layer, a light emitting layer, an electron transport layer, and a cathode are laminated on an anode provided on a glass substrate. The layer sandwiched between the anode and the cathode is mainly composed of an organic layer, and the thickness of each organic layer is as thin as several tens of nm.

The organic EL element is a laminated body of thin layers, and the total reflection angle of light between the thin layers is determined by the difference in refractive index between the materials of the thin layers. At present, about 80% of the light generated in the light emitting layer is confined inside the organic EL element and cannot be extracted outside. Specifically, when the refractive index of the glass substrate is 1.5 and the refractive index of the air layer is 1.0, the critical angle θ _c is 41.8 °, and the incident angle is smaller than the critical angle θ _c. the light is emitted from the glass substrate to the air layer, the light of the larger incident angle than the critical angle theta _c is confined within the glass substrate by total internal reflection. Therefore, it is required to extract light confined inside the glass substrate on the surface of the organic EL element to the outside of the glass substrate, that is, to improve light extraction efficiency and front luminance.

  In order to solve this problem, a method of laminating an optical film having a microlens on the light emitting surface of the organic EL element is conceivable. As a method for producing an optical film having this microlens, for example, Patent Document 1 proposes a method of curing by supplying an active energy ray-curable composition between a roll-type surface and a substrate. Yes.

International Publication No. 2014/021088 Pamphlet

However, since the method proposed in Patent Document 1 has a concave microlens transfer portion on the surface of a roll mold, there is a problem that bubbles are mixed when an active energy ray-curable composition is applied.
In order to solve this problem, a method of applying an active energy ray-curable composition to both the roll-type surface and the surface of the substrate and associating and curing them can be considered. Even if the active energy ray-curable composition is applied to both the roll-type surface and the surface of the substrate, the mixing of bubbles is not sufficient.

  By the way, when air bubbles are mixed in the optical film, the air bubble portion reduces the scattering intensity, which may cause a reduction in light extraction efficiency of the surface light emitter and front luminance. Therefore, regarding the bubbles in the optical film, it is necessary to control the size to mix the bubbles or not to mix the bubbles.

  Therefore, an object of the present invention is to provide a method for producing an optical film that is excellent in productivity and suppresses the mixing of bubbles.

The present invention is an optical film manufacturing method including the following steps A to D, which are sequentially executed, and the viscosity of the mixture B measured by a B-type viscometer at 40 ° C. according to ISO 2555 is 10 mPa · s. The manufacturing method of the optical film which is -600 mPa * s.
Step A: Rotate a roll mold having an outer peripheral surface on which a plurality of concave microlens transfer portions are arranged, and run the substrate along the outer periphery of the roll mold in the rotation direction of the roll mold while rotating the outer periphery of the roll mold Step of applying the mixture B containing the active energy ray-curable composition B to the surface and filling a part of the microlens transfer portion with the mixture B Step B: Active energy rays between the outer peripheral surface of the roll mold and the substrate Step of supplying the mixture A containing the curable composition A Step C: Region between the outer peripheral surface of the roll mold and the substrate in a state where at least the mixture A is sandwiched between the outer peripheral surface of the roll mold and the substrate. Step of irradiating active energy ray to step Step D: Step of peeling the cured product obtained in Step C from the roll mold

Moreover, this invention relates to the optical film obtained by the manufacturing method of the said optical film.
Furthermore, this invention relates to the surface light-emitting body containing the said optical film and EL element.

The method for producing an optical film of the present invention provides an optical film that is excellent in productivity and contains less bubbles.
Moreover, the optical film of the present invention has less air bubbles.
Furthermore, the surface light emitter of the present invention is excellent in light extraction efficiency and front luminance because there are few air bubbles in the optical film.

It is a schematic diagram which shows an example of the apparatus used for the manufacturing method of the optical film of this invention. It is a schematic diagram which shows an example of the cross section of the optical film of this invention. It is the schematic diagram which looked at the example of arrangement | positioning of the micro lens of the optical film of this invention from the upper direction of the optical film. It is the schematic diagram which looked at an example of the optical film of this invention from the upper direction of the optical film. It is a schematic diagram which shows an example of the cross section of the surface light-emitting body of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these drawings.

The manufacturing method of the optical film of this invention includes the following process AD performed sequentially.
Step A: Rotate a roll mold having an outer peripheral surface on which a plurality of concave microlens transfer portions are arranged, and run the substrate along the outer periphery of the roll mold in the rotation direction of the roll mold while rotating the outer periphery of the roll mold Step of applying the mixture B containing the active energy ray-curable composition B to the surface and filling a part of the microlens transfer portion with the mixture B Step B: Active energy rays between the outer peripheral surface of the roll mold and the substrate Step of supplying the mixture A containing the curable composition A Step C: Region between the outer peripheral surface of the roll mold and the substrate in a state where at least the mixture A is sandwiched between the outer peripheral surface of the roll mold and the substrate. Step of irradiating active energy ray to step Step D: Step of peeling the cured product obtained in Step C from the roll mold

As an apparatus used for the manufacturing method of the optical film of this invention, the apparatus 50 etc. which are shown in FIG. 1, etc. are mentioned, for example.
The apparatus used in the method for producing an optical film of the present invention is preferably the apparatus 50 shown in FIG. 1 because an optical film can be continuously produced.
In addition, the rotation direction and traveling direction of the roll mold 51 and the base material 17 in FIG. 1 are directions of arrows.

Hereinafter, the apparatus 50 shown in FIG. 1 will be described.
The mixture B containing the active energy ray-curable composition B is discharged from the first nozzle 52, flattened by the first doctor blade 54, and applied to the outer peripheral surface of the roll mold 51 by the first coating roll 53.
The mixture A containing the active energy ray-curable composition is discharged from the second nozzle 52 ′, flattened by the second doctor blade 54 ′, and applied to the substrate 17 by the second coating roll 53 ′.
The distance between the roll mold 51 and the nip roll 55 is adjusted, and the thickness of the base layer 15 of the optical film 10 is set.
While rotating the roll mold 51, the active energy beam irradiation device 56 irradiates and cures the area between the outer peripheral surface of the roll mold 51 and the substrate 17. By peeling the obtained cured product from the roll mold 51, the optical film 10 is obtained.

(Process A)
In step A, the roll mold 51 having an outer peripheral surface on which a plurality of concave microlens transfer portions are arranged is rotated, and the substrate 17 is caused to travel along the outer peripheral surface of the roll mold 51 in the rotation direction of the roll mold 51. This is a step of applying the mixture B containing the active energy ray-curable composition B to the outer peripheral surface of the roll mold 51 and filling a part of the microlens transfer portion with the mixture B.

The viscosity of the mixture B containing the active energy ray-curable composition B is 10 mPa · s to 600 mPa · s, preferably 20 mPa · s to 450 mPa · s, and more preferably 30 mPa · s to 300 mPa · s. When the viscosity of the mixture B containing the active energy ray-curable composition B is 10 mPa · s or more, it can be suppressed that the coating amount of the mixture B is insufficient. Moreover, when the viscosity of the mixture B containing the active energy ray-curable composition B is 600 mPa · s or less, mixing of bubbles in the microlens 11 can be suppressed.
The viscosity of the mixture in the present specification is a value measured with a B-type viscometer at 40 ° C. in accordance with ISO 2555.

The contact angle with the roll type of the active energy ray-curable composition B is preferably 30 ° to 80 °, more preferably 32 ° to 78 °, and still more preferably 35 ° to 75 °. When the contact angle between the active energy ray-curable composition B and the roll mold is 30 ° or more, the application amount of the mixture B can be suppressed from being insufficient. Moreover, mixing of the bubble in the microlens 11 can be suppressed as the contact angle with the roll type | mold of the active energy ray-curable composition B is 80 degrees or less.
The contact angle in this specification is based on JIS R 3257 and is a value measured by forming droplets of the active energy ray-curable composition B on a flat plate that is the same as the roll type used by the surface material. To do.

  Examples of the roll mold 51 include molds such as aluminum, brass, and steel; resin molds such as silicone resin, urethane resin, epoxy resin, ABS resin, fluororesin, and polymethylpentene resin; molds obtained by plating the resin; Examples include a mold made of a material obtained by mixing various metal powders with a resin. Among these roll molds, a mold is preferable because of excellent heat resistance and mechanical strength and suitable for continuous production. Specifically, the mold is preferable in many respects such as excellent durability against polymerization heat generation, hardly deformed, hardly scratched, temperature-controllable, and suitable for precision molding.

The roll mold 51 has a concave transfer portion corresponding to the convex shape in order to transfer and form the convex microlenses 11 of the optical film 10.
Examples of the method for producing the transfer portion include cutting with a diamond tool, etching as described in International Publication No. 2008/069324 pamphlet, and the like. Among these manufacturing methods of the transfer part, when forming a concave shape having a curved surface such as a spherical shape, etching is preferable because the roll mold 51 is excellent in productivity, and a concave not having a curved surface such as a pyramid shape. When forming the shape, cutting with a diamond bit is preferable because the productivity of the roll mold 51 is excellent.
In addition, as a method for manufacturing the transfer portion, a cylindrical roll die 51 is formed by winding a metal thin film produced by using an electroforming method from a master die having a depression and an inverted projection of the transfer portion around a roll core member. Manufacturing methods can be used.

  Heat source equipment such as a sheathed heater or a hot water jacket may be provided inside or outside the roll mold 51 as necessary in order to maintain the surface temperature.

  The rotational speed of the roll mold 51, that is, the traveling speed of the outer peripheral surface of the roll mold 51 is preferably 0.1 m / min to 50 m / min, and preferably 0.3 m / min to 40 m, because the optical film 10 is excellent in moldability and productivity. / Min is more preferable, and 0.5 m / min to 30 m / min is still more preferable.

When the mixture B containing the active energy ray-curable composition B is applied to the roll mold 51, it is preferable to apply the mixture B after flattening because the air bubbles in the microlenses 11 can be prevented from being mixed.
Examples of the flattening means include a doctor blade, an air blade, an air knife, a roll coater, and a bar coater. These flattening means may be used alone or in combination of two or more. Among these flattening means, a doctor blade is preferable because it can suppress the mixing of bubbles in the microlens 11.

When the mixture B containing the active energy ray-curable composition B is applied to the roll mold 51, the mixture of the bubbles in the outer peripheral surface of the roll mold 51 can be prevented from being mixed with bubbles in the microlens 11. It is preferable that the coating be made to follow the surface of the microlens transfer portion.
As a coating method for causing the mixture B to follow the surface of the microlens transfer portion, for example, while pressing a doctor blade, a roll coater or a bar coater having a tapered sharp tip against a rotating roll surface, the bank of the mixture B And a shearing force is applied to the mixture B by the peripheral edge of the concave microlens transfer portion and a doctor blade, roll coater or bar coater. As a result, surface tension is applied to the surface of the mixture B following the concave shape. The method etc. which comes to act are mentioned.

(Process B)
Step B is a step of supplying the mixture A containing the active energy ray-curable composition A between the outer peripheral surface of the roll mold 51 and the base material 17.

  The viscosity of the mixture A containing the active energy ray-curable composition A is preferably 650 mPa · s to 5000 mPa · s, and more preferably 750 mPa · s to 4000 mPa · s. If the viscosity of the mixture A containing the active energy ray-curable composition A is 650 mPa · s or more, sink marks of the optical film 10 can be suppressed. Moreover, the uniformity of the thickness of the optical film 10 is excellent in the viscosity of the mixture A containing the active energy ray-curable composition A being 5000 mPa · s or less.

  The viscosity of the mixture B is preferably smaller than the viscosity of the mixture A by 100 mPa · s to 4500 mPa · s, and more preferably 300 mPa · s to 3500 mPa · s. When the viscosity of the mixture B is smaller than the viscosity of the mixture A by 100 mPa · s or more, mixing of bubbles in the microlens 11 can be suppressed. Moreover, when the viscosity of the mixture B is 4500 mPa · s or less smaller than the viscosity of the mixture A, sink marks of the optical film 10 can be suppressed.

  The mixture A containing the active energy ray-curable composition A may be applied to the traveling substrate 17 and supplied, or supplied to the roll mold 51 to which the mixture B containing the active energy ray-curable composition B is applied. However, since the thickness of the base layer 15 can be controlled, it is preferable that the base layer 15 is applied and supplied.

When the mixture A containing the active energy ray-curable composition A is applied to the base material 17, it is preferable to apply the mixture A after flattening since the mixing of bubbles in the microlenses 11 can be suppressed.
Examples of the flattening means include a doctor blade, an air blade, an air knife, a roll coater, and a bar coater. These flattening means may be used alone or in combination of two or more. Among these flattening means, a bar coater is preferable because it can suppress the mixing of bubbles in the microlens 11.

(Process C)
Step C is a step of irradiating the region between the outer peripheral surface of the roll mold 51 and the base material 17 with active energy rays in a state where at least the mixture A is sandwiched between the outer peripheral surface of the roll mold 51 and the base material 17. It is.

Before the step C, a step of irradiating the active energy ray to the mixture B containing the active energy ray curable composition B and curing it may be included.
Through the above-described steps, a region α described later becomes a cured product of the mixture A, a region β described later becomes a cured product of the mixture B, and the interface between the region α and the region β becomes clear.
On the other hand, if the process is not performed, the entire inside of the microlens 11 becomes a cured product of the mixture of the mixture A and the mixture B, or the vicinity of the interface between the region α described later and the region β described later is gradationized.

  Examples of the active energy ray include ultraviolet rays, electron beams, X-rays, infrared rays, and visible rays. Among these active energy rays, ultraviolet rays and electron beams are preferable, and ultraviolet rays are more preferable because the active energy ray-curable composition is excellent in curability and can suppress deterioration of the optical film 10.

  Examples of the active energy ray light source include a chemical lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp, an electrodeless ultraviolet lamp, a visible light halogen lamp, and a xenon lamp.

Integrated light quantity of active energy rays, good curing of the active energy ray-curable composition, since it is possible to suppress deterioration of the optical film 10 is preferably ^{0.01J / cm 2 ~10J / cm 2} , 0. 5J ^/ cm ² ~8J ^/ cm 2 is more preferable.

(Process D)
Step D is a step of peeling the cured product obtained in Step C from the roll mold.

  In order to make it easy to peel the cured product from the roll mold, the roll mold may be subjected to a peeling treatment, or the mixture A or the mixture B may contain a release agent.

  Regarding the method for producing the optical film 10 of the present invention, it is possible to refer to the description in the pamphlet of International Publication No. 2013/080794.

(Optical film)
The optical film 10 of the present invention is obtained by the method for producing an optical film of the present invention.

(Micro lens)
Examples of the optical film 10 include the optical film 10 shown in FIG.
The optical film 10 shown in FIG. 2 includes a microlens layer 14 having a microlens 11, a base layer 15, and a base material 17 that are sequentially laminated. It consists of a region β shown.

Examples of the shape of the microlens 11 include a sphere shape, a sphere shape, an ellipsoid sphere shape (a shape obtained by cutting a spheroid on one plane), and an ellipsoid sphere shape (a spheroid is mutually connected). Shape cut by two parallel planes), pyramid shape, truncated pyramid shape, cone shape, truncated cone shape, and related roof shape (spherical shape, spherical truncated shape, ellipsoidal spherical shape, elliptical shape) And a truncated cone shape, a pyramid shape, a truncated pyramid shape, a cone shape, or a shape in which a truncated cone shape extends along the bottom surface portion). These microlenses 11 may be used singly or in combination of two or more. Among these microlenses 11, since the surface light emitter has excellent light extraction efficiency and front luminance, it has a spherical notch shape, a spherically truncated shape, an elliptical spherically truncated shape, an elliptical spherically truncated shape, a pyramid shape, A truncated pyramid shape is preferable, a spherical notch shape, an ellipsoidal spherical shape, and a pyramidal shape are more preferable, and a spherically truncated shape and an elliptical spherical shape are more preferable.
Each shape in this specification does not need to be exactly that shape, and includes shapes that are very similar.

An example of the arrangement of the microlenses 11 is shown in FIG.
As the arrangement of the microlenses 11, for example, a hexagonal arrangement (FIG. 3A), a rectangular arrangement (FIG. 3B), a rhombus arrangement (FIG. 3C), and a linear arrangement (FIG. 3D). , Circular arrangement (FIG. 3E), random arrangement (FIG. 3F), and the like. Among these arrangements of the microlenses 11, a hexagonal arrangement, a rectangular arrangement, and a rhombus arrangement are preferable, and a hexagonal arrangement and a rectangular arrangement are more preferable because of excellent light extraction efficiency and front luminance of the surface light emitter.

The bottom surface portion 16 of the microlens 11 refers to a virtual planar portion surrounded by the outer peripheral edge of the bottom portion of the microlens 11 (in the case of having the base layer 15 described later, the contact surface with the base layer 15).
The longest diameter L of the bottom surface portion 16 of the microlens 11 is the length of the longest portion of the bottom surface portion 16 of the microlens 11, and the average longest diameter L _ave of the bottom surface portion 16 of the microlens 11 is The surface having the microlens 11 is photographed with an electron microscope, and the longest diameter L of the bottom surface portion 16 of the microlens 11 is measured at any five locations, and the average value is obtained.

The height H of the micro lens 11, refers to the height from the bottom portion 16 of the microlens 11 to the highest portion of the micro-lens 11, the average height H _ave of the micro lens 11, electrons cross section of an optical film 10 Photographed with a microscope, the height H of the microlens 11 is measured at any five points, and the average value is obtained.
The height h of the region α refers to the height from the bottom surface portion 16 of the microlens 11 to the highest portion of the region α, and the average height h _ave of the region α is a cross section of the optical film 10 by an electron microscope. The image is taken, and the height h of the region α is measured at five arbitrary points, and the average value is obtained.

The average longest diameter L _ave of the bottom surface portion 16 of the microlens 11 is preferably 2 μm to 200 μm, more preferably 6 μm to 150 μm, and even more preferably 10 μm to 100 μm, because the light extraction efficiency and front luminance of the surface light emitter are excellent.

The average height H _ave of the microlens 11 is preferably 1 μm to 100 μm, more preferably 3 μm to 75 μm, and even more preferably 5 μm to 50 μm, because of excellent light extraction efficiency and front luminance of the surface light emitter.

The aspect ratio of the microlens 11 is preferably 0.3 to 1.4, more preferably 0.35 to 1.3, and more preferably 0.4 to 1. 0 is more preferable.
The aspect ratio of the micro lens 11 is a value calculated from the average height H _{ave of the} micro lens 11 / the average longest diameter L _ave of the bottom surface portion 16 of the micro lens 11.

  Examples of the shape of the bottom surface portion 16 of the microlens 11 include a polygon such as a triangle and a quadrangle; a circle such as a perfect circle and an ellipse; and an indefinite shape. As the shape of the bottom surface portion 16 of these microlenses 11, one type may be used alone, or two or more types may be used in combination. Among these shapes of the bottom surface portion 16 of the microlens 11, a polygonal shape and a circular shape are preferable, and a circular shape is more preferable because of excellent light extraction efficiency and front luminance of the surface light emitter.

An example of the optical film 10 viewed from above is shown in FIG.
The ratio of the area of the bottom surface portion 16 of the microlens 11 (the area surrounded by the dotted line in FIG. 4) to the area of the optical film 10 (the area surrounded by the solid line in FIG. 4) is the light extraction efficiency of the surface light emitter. And 20% to 100% is preferable, 25% to 97% is more preferable, and 30% to 94% is even more preferable.

The average height h _ave of the region α is preferably 0.5 μm to 80 μm, more preferably 1.5 μm to 60 μm, and even more preferably 2.5 μm to 30 μm, because the light extraction efficiency and front luminance of the surface light emitter are excellent. .

The ratio of the average height h _ave of the region α to the average height H _ave of the microlens 11 (h _ave / H _ave ) is excellent in light extraction efficiency and front luminance of the surface light emitter, and is 0.05 to 0. 96 is preferable, 0.1 to 0.92 is more preferable, and 0.2 to 0.88 is still more preferable.

The average volume ratio of the region α is preferably 1% by volume to 90% by volume and more preferably 2% by volume to 80% by volume since the role of the region α in the optical film 10 is sufficiently fulfilled in 100% by volume of the microlens. 3 volume%-70 volume% is still more preferable.
The average volume ratio of the region α is synonymous with the volume ratio of the cured product of the mixture A in the microlens.
The average volume ratio of the region β is preferably 10% by volume to 99% by volume, more preferably 20% by volume to 98% by volume because the role of the region β in the optical film 10 is sufficiently fulfilled in 100% by volume of the microlens. 30 volume%-97 volume% are still more preferable.
The average volume ratio of the region β is synonymous with the volume ratio of the cured product of the mixture B in the microlens.

In the microlens 11, another region may exist between the region α and the region β. The other region may be a single layer or a plurality of layers.
Examples of the other region include an intermediate region having a refractive index between the refractive index of the matrix resin M _α constituting the region α and the refractive index of the matrix resin M _β constituting the region β. By providing such an intermediate region, the Fresnel reflection loss is further reduced, so that a surface light emitter that is more excellent in light extraction efficiency can be obtained.

(Region α)
The region α preferably includes a matrix resin M _α and light diffusion particles P _α .

The matrix resin M _α constituting the region α is not particularly limited as long as it has a high light transmittance in the visible light wavelength region (approximately 400 nm to 700 nm). For example, acrylic resin; polycarbonate resin; polyethylene terephthalate, polybutylene terephthalate And polyester resins such as polyethylene naphthalate; styrene resins such as polystyrene and ABS resin; and vinyl chloride resins. These matrix resins _Mα may be used alone or in combination of two or more. Among these matrix resins M _alpha, high transmittance in the visible light wavelength range, heat resistance, mechanical properties, since it is excellent in molding processability, acrylic resins, styrene resins are preferred, acrylic resins are preferred.

Light transmittance of the matrix resin M _alpha is excellent in appearance of the optical film 10, because of its excellent light extraction efficiency and front brightness of the surface light emitters, preferably 50% to 95%, more preferably 60% to 90%.
The light transmittance of each resin in the present specification is a value measured according to ISO 13468.

Refractive index of the matrix resin M _alpha is excellent in light extraction efficiency and front brightness of the surface light emitters, preferably 1.40 to 2.00, more preferably 1.43 to 1.90, 1.46 to 1 .80 is more preferred.
The refractive index of each material in this specification shall be the value measured using the sodium D line | wire at 20 degreeC.

Since the matrix resin _Mα is excellent in the productivity of the optical film 10, a resin obtained by irradiating the active energy ray-curable composition with active energy rays and curing it is preferable.
Examples of the active energy ray include ultraviolet rays, electron beams, X-rays, infrared rays, and visible rays. Among these active energy rays, ultraviolet rays and electron beams are preferable, and ultraviolet rays are more preferable because the active energy ray-curable composition is excellent in curability and can suppress deterioration of the optical film 10.

  The active energy ray-curable composition is not particularly limited as long as it can be cured by active energy rays. However, the active energy ray-curable composition is excellent in handleability and curability, and the optical film 10 has flexibility, heat resistance, and scratch resistance. , An active energy ray-curable composition containing a non-crosslinkable monomer (A), a crosslinkable monomer (B), and a polymerization initiator (C) because of excellent physical properties such as solvent resistance and light transmittance Things are preferred.

Examples of the non-crosslinkable monomer (A) include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, iso-propyl (meth) acrylate, n-butyl (meth) acrylate, iso-butyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl ( (Meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, stearyl (meth) acrylate, alkyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylic , Isobornyl (meth) acrylate, glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, norbornyl (meth) acrylate, adamantyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentanyl (meth) Acrylate, tetracyclododecanyl (meth) acrylate, cyclohexanedimethanol mono (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxy Butyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-eth Siethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, butoxyethyl (meth) acrylate, methoxytriethylene glycol (meth) acrylate, methoxydipropylene glycol (meth) acrylate, 2- (meth) acryloyloxymethyl-2 -Methylbicycloheptane, 4- (meth) acryloyloxymethyl-2-methyl-2-ethyl-1,3-dioxolane, 4- (meth) acryloyloxymethyl-2-methyl-2-isobutyl-1,3-dioxolane , (Meth) acrylates such as trimethylolpropane formal (meth) acrylate, ethylene oxide modified phosphoric acid (meth) acrylate and caprolactone modified phosphoric acid (meth) acrylate; (meth) acrylic acid; (meth) acrylonitrile (Meth) acrylamide, N-dimethyl (meth) acrylamide, N-diethyl (meth) acrylamide, N-butyl (meth) acrylamide, dimethylaminopropyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxy (Meth) acrylamides such as methyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, (meth) acryloylmorpholine, hydroxyethyl (meth) acrylamide, and methylenebis (meth) acrylamide; bisphenols (bisphenol A, bisphenol F, (Meth) acrylic acid or a derivative thereof is reacted with a bisphenol type epoxy resin obtained by condensation reaction of bisphenol S, tetrabromobisphenol A, etc.) and epichlorohydrin Epoxy (meth) acrylates; aromatic vinyls such as styrene and α-methylstyrene; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and 2-hydroxyethyl vinyl ether; vinyl carboxylates such as vinyl acetate and vinyl butyrate Olefins such as ethylene, propylene, butene and isobutene; These non-crosslinkable monomers (A) may be used individually by 1 type, and may use 2 or more types together. Among these non-crosslinkable monomers (A), the handleability and curability of the active energy ray-curable composition are excellent, and the flexibility, heat resistance, scratch resistance, solvent resistance, and light transmission of the optical film 10 are excellent. (Meth) acrylates, epoxy (meth) acrylates, and olefins are preferable, and (meth) acrylates and epoxy (meth) acrylates are more preferable.
(Meth) acrylate refers to acrylate or methacrylate.

  The content of the non-crosslinkable monomer (A) is preferably 0.5% by mass to 60% by mass and more preferably 1% by mass to 57% by mass in 100% by mass of the active energy ray-curable composition. A mass% to 55 mass% is more preferable. When the content of the non-crosslinkable monomer (A) is 0.5% by mass or more, the handleability of the active energy ray-curable composition is excellent, and the adhesiveness of the optical film 10 to the base material is excellent. When the content of the non-crosslinkable monomer (A) is 60% by mass or less, the active energy ray-curable composition is excellent in crosslinkability and curability, and the optical film 10 is excellent in solvent resistance.

  Examples of the crosslinkable monomer (B) include hexa (meth) acrylates such as dipentaerythritol hexa (meth) acrylate and caprolactone-modified dipentaerythritol hexa (meth) acrylate; dipentaerythritol hydroxypenta (meth) acrylate , Penta (meth) acrylates such as caprolactone-modified dipentaerythritol hydroxypenta (meth) acrylate; ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol ethoxy modified tetra (meth) acrylate, dipenta Tests such as erythrole hexa (meth) acrylate, dipentaerystol penta (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, etc. La (meth) acrylates; trimethylolpropane tri (meth) acrylate, trisethoxylated trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, ethoxylated pentaerythritol tri (meth) acrylate, tris ( Tri (meth) acrylates such as 2- (meth) acryloyloxyethyl) isocyanurate, C2-C5 aliphatic hydrocarbon modified trimethylolpropane tri (meth) acrylate, isocyanuric acid ethylene oxide modified tri (meth) acrylate Triethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, 1,4-butanediol di (meth) Acrylate, 1,5-pentanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, nonanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, methylpentanediol di (meth) Acrylate, diethylpentanediol di (meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polybutylene glycol di (meth) acrylate, Tricyclodecane dimethanol di (meth) acrylate, 2,2-bis (4- (meth) acryloxypolyethoxyphenyl) propane, 2,2-bis (4- (meth) acryloxyethoxy) Enyl) propane, 2,2-bis (4- (3- (meth) acryloxy-2-hydroxypropoxy) phenyl) propane, 1,2-bis (3- (meth) acryloxy-2-hydroxypropoxy) ethane, 1 , 4-bis (3- (meth) acryloxy-2-hydroxypropoxy) butane, bis (2- (meth) acryloyloxyethyl) -2-hydroxyethyl isocyanurate, cyclohexanedimethanol di (meth) acrylate, dimethyloltri Cyclodecane di (meth) acrylate, hydroxypivalic acid neopentyl glycol di (meth) acrylate, polyethoxylated cyclohexanedimethanol di (meth) acrylate, polypropoxylated cyclohexanedimethanol di (meth) acrylate, polyethoxy Rated bisphenol A di (meth) acrylate, polypropoxylated bisphenol A di (meth) acrylate, hydrogenated bisphenol A di (meth) acrylate, polyethoxylated hydrogenated bisphenol A di (meth) acrylate, polypropoxylated Di (meth) of hydrogenated bisphenol A di (meth) acrylate, bisphenoxyfluoreneethanol di (meth) acrylate, neopentyl glycol modified trimethylolpropane di (meth) acrylate, and ε-caprolactone adduct of hydroxypivalate neopentyl glycol Di (meth) acrylate of γ-butyrolactone adduct of acrylate, neopentyl glycol hydroxypivalate, di (meth) of caprolactone adduct of neopentyl glycol Di (meth) acrylate of caprolactone adduct of chlorate, butylene glycol, di (meth) acrylate of caprolactone adduct of cyclohexanedimethanol, di (meth) acrylate of caprolactone adduct of dicyclopentanediol, ethylene oxide addition of bisphenol A Di (meth) acrylate of a product, di (meth) acrylate of a propylene oxide adduct of bisphenol A, di (meth) acrylate of a caprolactone adduct of bisphenol A, di (meth) acrylate of a caprolactone adduct of hydrogenated bisphenol A, Di (meth) acrylates such as di (meth) acrylates of caprolactone adducts of bisphenol F, isocyanuric acid ethylene oxide-modified di (meth) acrylates; , Diallyl such as diallyl terephthalate, diallyl isophthalate, diethylene glycol diallyl carbonate; allyl (meth) acrylate; divinylbenzene; methylenebisacrylamide; polybasic acid (phthalic acid, succinic acid, hexahydrophthalic acid, tetrahydrophthalic acid, terephthalic acid , Azelaic acid, adipic acid and the like) and polyhydric alcohols (ethylene glycol, hexanediol, polyethylene glycol, polytetramethylene glycol, etc.) and (meth) acrylic acid or a compound obtained by reaction with a derivative thereof ( (Meth) acrylates; diisocyanate compounds (tolylene diisocyanate, isophorone diisocyanate, xylene diisocyanate, dicyclohexylmethane diisocyanate, hexamethyl) Range isocyanates) and hydroxyl-containing (meth) acrylates (2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, pentaerythritol tri (meth) acrylate) A diisocyanate compound was added to the hydroxyl group of a compound obtained by reacting with a functional (meth) acrylate or the like, or an alcohol (one kind or two or more kinds such as an alkanediol, a polyether diol, a polyester diol, and a spiroglycol compound) and remained. Urethane polyfunctional (meth) acrylates such as compounds obtained by reacting an isocyanate group with a hydroxyl group-containing (meth) acrylate; divinyl ethers such as diethylene glycol divinyl ether and triethylene glycol divinyl ether; Tajien, isoprene, dienes such as dimethyl butadiene and the like. These crosslinkable monomers (B) may be used individually by 1 type, and may use 2 or more types together. Among these crosslinkable monomers (B), the optical film 10 has excellent physical properties such as flexibility, heat resistance, scratch resistance, solvent resistance, and light transmittance, and can increase the refractive index. , Hexa (meth) acrylates, penta (meth) acrylates, tetra (meth) acrylates, tri (meth) acrylates, di (meth) acrylates, diallyls, allyl (meth) acrylate, polyester di (meth) Acrylates and urethane polyfunctional (meth) acrylates are preferred, hexa (meth) acrylates, penta (meth) acrylates, tetra (meth) acrylates, tri (meth) acrylates, di (meth) acrylates, polyester Di (meth) acrylates and urethane polyfunctional (meth) acrylates are more preferable. Distearate (meth) acrylates, urethane polyfunctional (meth) acrylates are more preferred.

  30 mass%-98 mass% are preferable in 100 mass% of active energy ray-curable compositions, and, as for the content rate of a crosslinkable monomer (B), 35 mass%-97 mass% are more preferable, and 40 mass%- 96 mass% is still more preferable. When the content of the crosslinkable monomer (B) is 30% by mass or more, the crosslinkability and curability of the active energy ray-curable composition are excellent, and the solvent resistance of the optical film 10 is excellent. Moreover, it is excellent in the softness | flexibility of the optical film 10 as the content rate of a crosslinkable monomer (B) is 98 mass% or less.

  Examples of the polymerization initiator (C) include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, acetoin, benzyl, benzophenone, p-methoxybenzophenone, 2,2-diethoxyacetophenone, α, α-dimethoxy-α-phenylacetophenone, benzyldimethyl ketal, methylphenylglyoxylate, ethylphenylglyoxylate, 4,4′-bis (dimethylamino) benzophenone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2- Carbonyl compounds such as methyl-1-phenylpropan-1-one and 2-ethylanthraquinone; tetramethylthiuram monosulfide, tetramethylthiuram disulfide and the like Huang compounds; 2,4,6-trimethylbenzoyl diphenylphosphine oxide, acylphosphine oxide such as benzo dichloride ethoxy phosphine oxide, and the like. These polymerization initiators (C) may be used individually by 1 type, and may use 2 or more types together. Among these polymerization initiators (C), carbonyl compounds and acyl phosphine oxides are preferred because they are excellent in handling and curability of the active energy ray-curable composition and light transmittance of the optical film 10, and carbonyl compounds are preferred. Is more preferable.

  The content of the polymerization initiator (C) in the active energy ray-curable composition is preferably 0.1% by mass to 10% by mass, and preferably 0.5% by mass to 100% by mass in the active energy ray-curable composition. 8 mass% is more preferable, and 1 mass%-5 mass% is still more preferable. When the content of the polymerization initiator (C) is 0.1% by mass or more, the handleability and curability of the active energy ray-curable composition are excellent. Moreover, it is excellent in the light transmittance of the optical film 10 as the content rate of a polymerization initiator (C) is 10 mass% or less.

The fine particles P _alpha included in the area alpha, not be particularly limited provided that they are particles having a light diffusion effect of the visible light wavelength region (approximately 400 nm to 700 nm), it may be a known particle. The fine particles _Pα may be used alone or in combination of two or more.

As the material of the light diffusing fine particles P _alpha, for example, gold and silver, silicon, aluminum, magnesium, zirconium titanium, zinc germanium, indium, tin, antimony, a metal of cerium and the like; silicon oxide, aluminum oxide, magnesium oxides, Metal oxides such as zirconium oxide, titanium oxide, zinc oxide, germanium oxide, indium oxide, tin oxide, indium tin oxide, antimony oxide and cerium oxide; metal hydroxide such as aluminum hydroxide; metal carbonate such as magnesium carbonate Examples thereof include metal nitrides such as silicon nitride; resins such as acrylic resins, styrene resins, silicone resins, urethane resins, melamine resins, and epoxy resins. Materials of these fine particles P _alpha may be used alone or in combination of two or more thereof. Among these fine particle _Pα materials, silicon, aluminum, magnesium, silicon oxide, aluminum oxide, magnesium oxide, aluminum hydroxide, magnesium carbonate, acrylic resin, styrene are excellent because they are easy to handle at the time of manufacturing the optical film 10. Resins, silicone resins, urethane resins, melamine resins, and epoxy resins are preferred, and silicon oxide, aluminum oxide, aluminum hydroxide, magnesium carbonate, acrylic resins, styrene resins, silicone resins, urethane resins, melamine resins, and epoxy resin particles are more An acrylic resin and a silicone resin are more preferable, and a silicone resin is particularly preferable.

Refractive index of the fine particles P _alpha is excellent in light extraction efficiency and front brightness of the surface light emitters, preferably 1.30 to 2.00, more preferably 1.35 to 1.90, 1.40 to 1. 80 is more preferable.

The volume average particle diameter of the fine particles P _alpha is preferably 0.5 ~ 10 m, more preferably 1Myuemu～8myuemu, more preferably 1.5Myuemu～6myuemu. When the volume average particle diameter of the fine particles P _alpha is at 0.5μm or more, it can be effectively scatter light in the visible wavelength range. Further, the volume average particle diameter of the fine particles P _alpha is at 10μm or less, it is possible to suppress the emission angle dependence of the emission wavelength of the surface light emitter.
The volume average particle diameter of each fine particle in the present specification is a value measured by a laser diffraction scattering method.

The shape of the fine particles P _alpha, for example, spherical, cylindrical, cubic, cuboid, pyramid, cone, star-shaped, irregular shape and the like. The shape of these fine particles P _alpha may be used alone or in combination of two or more thereof. Among shape of these fine particles P _alpha, since it is possible to effectively scatter the light in the visible wavelength range, spherical, cubic, rectangular parallelepiped, pyramid, preferably star-shaped, spherical is more preferable.

Since the matrix resin M _α and the fine particles P _α have a difference in refractive index, the effect of the fine particles P _α is generated.
Refractive index difference between the matrix resin M _alpha and the fine particles P _alpha is preferably 0.05 to 0.30, preferably 0.07 to 0.27, 0.10-0.25 is more preferable. If the refractive index difference between the matrix resin M _alpha and the fine particles P _alpha is 0.05 or more, excellent in front brightness of the surface light emitter, it is possible to suppress the emission angle dependence of the emission wavelength of the surface light emitter. Further, the refractive index difference between the matrix resin M _alpha and the fine particles P _alpha is 0.30 or less, excellent light extraction efficiency and front brightness of the surface light emitter.
The refractive index of the fine particles P _α is preferably lower than the refractive index of the matrix resin M _α because the emission angle dependency of the emission light wavelength of the surface light emitter can be suppressed.

The combination of the matrix resin M _alpha and the fine particles P _alpha is, the heat resistance of the optical film 10, mechanical properties, excellent moldability, a preferred range the refractive index difference is above the light-extraction efficiency and front brightness of the surface light emitter Since it is excellent and the emission angle dependency of the emission light wavelength of the surface light emitter can be suppressed, the matrix resin M _α is an acrylic resin, the fine particles P _α are silicon oxide fine particles, the matrix resin M _α is an acrylic resin, and the fine particles P _α are Aluminum oxide fine particles, matrix resin M _α is acrylic resin and fine particles P _α are aluminum hydroxide fine particles, matrix resin M _α is acrylic resin and fine particles P _α are magnesium carbonate fine particles, matrix resin M _α is acrylic resin and fine particles P _α are acrylic fine resin particles, the matrix resin M _alpha microparticles P _alpha styrene resin particles with an acrylic resin, Ma Helix resin M _alpha microparticles P _alpha silicone resin fine particles in acrylic resin, the matrix resin M _alpha microparticles P _alpha urethane resin fine particles in acrylic resin, the matrix resin M _alpha microparticles P _alpha melamine resin fine particles in acrylic resin, the matrix resin M _α is acrylic resin and fine particles P _α are preferably epoxy resin fine particles, matrix resin M _α is acrylic resin and fine particles P _α are acrylic resin fine particles, matrix resin M _α is acrylic resin and fine particles P _α are styrene resin fine particles, matrix resin M _α is acrylic resin and fine particles P _α are silicone resin fine particles, matrix resin M _α is acrylic resin and fine particles P _α are urethane resin fine particles, matrix resin M _α is acrylic resin and fine particles P _α are melamine resin fine particles, matrix resin M _α Acrylic resin with fine particles _alpha is more preferably an epoxy resin fine particles, fine particles in the matrix resin M _alpha microparticles P _alpha acrylic resin fine particles in acrylic resin, the matrix resin M _alpha microparticles P _alpha silicone resin fine particles in acrylic resin, the matrix resin M _alpha acrylic resin P _α is more preferably a melamine resin fine particle, a matrix resin M _α is an acrylic resin, and a fine particle P _α is particularly preferably a silicone fine particle.

The content of the fine particles P _alpha, compared matrix resin M _alpha 100 parts by weight, preferably 40 parts by mass to 200 parts by mass, more preferably 50 parts by weight to 100 parts by weight. When the content of the fine particles P _alpha is 40 parts by mass or more, excellent in front brightness of the surface light emitter, it is possible to suppress the emission angle dependence of the emission wavelength of the surface light emitters, suppress shrinkage of the optical film 10 can do. If the content of the fine particles P _alpha is at most 200 parts by mass, excellent light extraction efficiency and front brightness of the surface light emitter, excellent uniformity of the thickness of the optical film 10.

(Region β)
Region beta preferably includes a light-diffusing particles P _beta according to _beta and optionally matrix resin M.

The matrix resin M _β constituting the region β may be the same as or different from the matrix resin M _α constituting the region α, but is excellent in light extraction efficiency and front luminance of the surface light emitter. Are preferably the same.
The same in this specification does not need to be exactly the same, and includes slightly different things.

Examples of the matrix resin _Mβ are the same as those described above (region α), and the same range is preferable for the same reason.

Since the matrix resin _Mβ is excellent in the productivity of the optical film 10, a resin obtained by irradiating the active energy ray-curable composition with an active energy ray and cured is preferable. The flexibility, heat resistance, and resistance of the optical film 10 are preferable. Active energy ray curing containing non-crosslinkable monomer (A), crosslinkable monomer (B) and polymerization initiator (C) because of excellent physical properties such as scratch resistance, solvent resistance, and light transmittance Is preferred.

Non-crosslinkable monomer for constituting the matrix resin M _beta (A), the kind and content of the crosslinkable monomer (B) and polymerization initiator (C) for constituting the matrix resin M _alpha The same thing as a non-crosslinkable monomer (A), a crosslinkable monomer (B), and a polymerization initiator (C) is mentioned, The same range is preferable for the same reason.

Light transmittance of the matrix resin M _beta, the refractive index, light transmittance of the matrix resin M _alpha, preferably the same range for the same reason as the refractive index.

The content of the fine particles P _beta, compared matrix resin M _beta 100 parts by weight of 0 parts by weight to 35 parts by weight are preferred, 0 parts by 20 mass parts is more preferable. When the content of the fine particles P _beta is less than 35 parts by mass, excellent light extraction efficiency and front brightness of the surface light emitter, it is possible to suppress the mixing of air bubbles in the micro lenses 11.

If the region beta contains fine particles P _beta, materials of the fine particles P _beta, the shape include those similar to the aforementioned (area alpha), preferably the same range as described above for the same reason as described above.
If the region beta contains fine particles P _beta, the refractive index of the fine particles P _beta, the volume average particle diameter is preferably the same range as described above for the same reason as the above (regions alpha).

If the region beta contains fine particles P _beta, a combination of a matrix resin M _beta and particulate P _beta has include those similar to the aforementioned (area alpha), preferably the same range as described above for the same reason as described above.
If the region beta contains fine particles P _beta, the refractive index difference between the matrix resin M _beta and particulate P _beta is preferably the same range as described above for the same reason as the above (regions alpha).

  In addition to the matrix resin and the fine particles, the region α and the region β may contain other additives as long as the performance of the optical film 10 is not impaired.

  Other additives include, for example, release agents, ultraviolet absorbers, light stabilizers, antistatic agents, flame retardants, antifoaming agents, leveling agents, antifouling improvers, dispersion stabilizers, viscosity modifiers, etc. Is mentioned.

  Since the content of the other additive can improve the characteristics of the other additive without impairing the performance of the optical film 10, the content of the other additive is 100 parts by mass of the matrix resin in both the region α and the region β. 10 parts by mass or less is preferable, and 5 parts by mass or less is more preferable.

(Base layer)
Since the optical film 10 supports the structure of the microlens 11, it is preferable to provide the base layer 15, for example, the optical film 10 as shown in FIG.

  The thickness of the base layer 15 is preferably 3 μm to 60 μm and more preferably 5 μm to 50 μm because the optical film 10 is excellent in flexibility and adhesion to the substrate.

  The region α and the base layer 15 may have the same or different material composition, but the material composition is preferably the same because the productivity of the optical film 10 is excellent.

(Base material)
In order to keep the shape of the optical film 10 on the light incident surface side of the optical film 10, a base material may be provided.
Since the base material is excellent in curability of the active energy ray-curable composition, a base material that transmits active energy rays is preferable.

  Examples of the material of the base material include acrylic resin; polycarbonate resin; polyester resin such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; styrene resin such as polystyrene and ABS resin; vinyl chloride resin; diacetyl cellulose, triacetyl cellulose, and the like. Cellulose resin; imide resin such as polyimide and polyimide amide; glass; metal. Among these base materials, acrylic resin, polycarbonate resin, polyester resin, styrene resin, vinyl chloride resin, cellulose resin, and imide resin are preferable because of excellent flexibility and excellent transmission of active energy rays. Resins, polycarbonate resins, polyester resins, and imide resins are more preferable, and polyester resins are more preferable.

  The thickness of the substrate is preferably 10 μm to 1000 μm, more preferably 20 μm to 500 μm, and still more preferably 25 μm to 300 μm, since the thickness of the substrate is excellent in the handleability of the optical film 10 and the curability of the active energy ray curable composition.

In order to improve the adhesiveness with the optical film 10, a base material may perform an easily bonding process on the surface of a base material as needed.
Examples of the method for easy adhesion treatment include a method for forming an easy adhesion layer made of a polyester resin, an acrylic resin, a urethane resin, or the like on the surface of the substrate, and a method for roughening the surface of the substrate.

  In addition to the easy adhesion treatment, the base material may be subjected to surface treatments such as antistatic, antireflection, and adhesion prevention between the base materials as necessary.

  The refractive index of the substrate is preferably 1.50 to 2.00, more preferably 1.53 to 1.90, and more preferably 1.56 to 1.80, since the surface light emitter has excellent light extraction efficiency and front luminance. Is more preferable.

(Adhesive layer)
An adhesive layer may be provided on the light incident surface side of the optical film 10 in order to adhere to the EL element. In the case of having a base material, an adhesive layer may be provided on the surface of the base material.
Examples of the adhesive layer include a layer using a known adhesive.

(Protective film)
In order to improve the handleability of the optical film 10 on the light incident surface side or the light emitting surface side of the optical film 10, a protective film may be provided. The protective film may be peeled off from the optical film 10 or the like when the optical film 10 or the like is pasted on the surface of the EL element or used as a surface light emitter.
As a protective film, a well-known protective film etc. are mentioned, for example.

(Surface emitter)
The surface light emitter of the present invention includes the optical film 10 and the EL element 30.
Examples of the surface light emitter of the present invention include a surface light emitter shown in FIG.
The surface light emitter shown in FIG. 5 is optically coupled to the surface of the glass substrate 31 of the EL element 30 in which the glass substrate 31, the anode 32, the light emitting layer 33, and the cathode 34 are sequentially laminated via the adhesive layer 21 and the base material 17. A film 10 is laminated.

  The surface light emitter of the present invention is excellent in light extraction efficiency and front luminance because it contains less bubbles in the optical film, and can be suitably used for lighting, displays, screens, and the like.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples.

(Measurement of bubble content)
Of the optical films (300 mm × 600 mm) obtained in Examples and Comparative Examples, the part containing bubbles was visually confirmed to calculate the area thereof, and the bubble content (area%) was calculated using the following formula.
Bubble content (area%) = (area of bubble-containing portion / area of optical film) × 100 (%)

(material)
Active energy ray curable composition A: Active energy ray curable composition produced in Production Example 1 described later (refractive index of cured product 1.52, contact angle 35 °)
Fine particles A: Silicone resin spherical fine particles (trade name “TSR9000”, manufactured by Mentive Performance Materials, refractive index 1.42, volume average particle diameter 2 μm)

[Production Example 1]
(Production of active energy ray-curable composition A)
In a glass flask, 117.6 g (0.7 mol) of hexamethylene diisocyanate as a diisocyanate compound, 151.2 g (0.3 mol) of an isocyanurate type hexamethylene diisocyanate trimer, 2 as a hydroxyl group-containing (meth) acrylate 128.7 g (0.99 mol) of hydroxypropyl acrylate and 693 g (1.54 mol) of pentaerythritol triacrylate, 22.1 g of di-n-butyltin dilaurate as a catalyst, and 0.55 g of hydroquinone monomethyl ether as a polymerization inhibitor The mixture was heated to 75 ° C., stirred while maintaining the temperature at 75 ° C., reacted until the concentration of the residual isocyanate compound in the flask was 0.1 mol / L or less, cooled to room temperature, A functional acrylate was obtained.
35 parts by mass of the obtained urethane polyfunctional acrylate, 20 parts by mass of polybutylene glycol dimethacrylate (trade name “Acryester PBOM”, manufactured by Mitsubishi Rayon Co., Ltd., number average molecular weight 650), diethylene oxide adduct of bisphenol A 40 parts by mass of (meth) acrylate (trade name “New Frontier BPEM-10”, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), phenoxyethyl acrylate (trade name “New Frontier PHE”, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 5 An active energy ray-curable composition A was obtained by mixing 1 part by mass and 1.2 parts by mass of 1-hydroxycyclohexyl phenyl ketone (trade name “Irgacure 184”, manufactured by BASF).

(Manufacture of roll molds)
Copper plating with a thickness of 200 μm and a Vickers hardness of 230 Hv was applied to the outer peripheral surface of a steel roll having an outer diameter of 200 mm and an axial length of 320 mm. The surface of the copper plating layer is coated with a photosensitizer, subjected to laser exposure, development and etching, and chrome plating is applied to the surface to give rust prevention and durability, resulting in a hemispherical depression having a diameter of 50 μm and a depth of 25 μm. A roll mold was obtained in which microlens transfer portions arranged in a hexagonal array with a minimum spacing of 3 μm were formed.

[Example 1]
While rotating the roll mold obtained in Production Example 2 and running a polyethylene terephthalate base material (trade name “Cosmo Shine A4100”, manufactured by Toyobo Co., Ltd.) in the rotation direction of the roll mold along the outer peripheral surface of the roll mold Then, 38% by volume of the mixture B (viscosity 150 mPa · s) shown in Table 1 was applied to the outer peripheral surface of the roll mold, and a part of the microlens transfer portion was filled with the mixture B. Next, 62% by volume of the mixture A (viscosity 3000 mPa · s) shown in Table 1 is applied between the outer peripheral surface of the roll mold and the running base material, and between the outer peripheral surface of the roll mold and the base material. In the state where the mixture A and the mixture B were sandwiched in the region, UV rays were irradiated and cured. The obtained cured product was peeled from the roll mold to obtain an optical film.
The composition in the microlens was 44% by volume of the cured product of the mixture A and 56% by volume of the cured product of the mixture B. The thickness of the base layer was 20 μm. Furthermore, from the photograph of the surface of the optical film having microlenses taken with an electron microscope, the ratio of the area of the bottom surface of the microlens to the area of the optical film was 73%.
The evaluation results of the obtained optical film are shown in Table 1.

[Examples 2-12, Comparative Examples 1-2]
A surface light emitter was obtained in the same manner as in Example 1 except that the composition of the mixture and the thickness of the base layer were changed as shown in Table 1.
The evaluation results of the obtained optical film are shown in Table 1.
In any of the examples and comparative examples, the composition in the microlens is 44% by volume of the cured product of the mixture constituting the region α and 56% by volume of the cured product of the mixture constituting the region β. The coating amount of the mixture was adjusted.

The optical films obtained in Examples 1 to 12 were able to suppress the mixing of bubbles.
On the other hand, since the optical films obtained in Comparative Examples 1 and 2 did not adjust the viscosity of the mixture, mixing of bubbles could not be suppressed.

  The method for producing an optical film of the present invention provides an optical film that is excellent in productivity and contains less bubbles. The surface light emitter of the present invention is excellent in light extraction efficiency and front luminance because it contains less bubbles in the optical film, and can be suitably used for lighting, displays, screens, and the like.

10 optical film 11 micro lens 12 region α
13 region β
DESCRIPTION OF SYMBOLS 14 Microlens layer 15 Base layer 16 Microlens bottom part 17 Base material 21 Adhesive layer 30 EL element 31 Glass substrate 32 Anode 33 Light emitting layer 34 Cathode 50 Device 51 Roll type 52 1st nozzle 52 '2nd nozzle 53 2nd nozzle 53 1 coating roll 53 ′ second coating roll 54 first doctor blade 54 ′ second doctor blade 55 nip roll 56 active energy ray irradiation device

Claims (8)

A method for producing an optical film, comprising the following steps A to D sequentially executed:
A method for producing an optical film, wherein the viscosity of the mixture B measured with a B-type viscometer at 40 ° C. in accordance with ISO 2555 is 10 mPa · s to 600 mPa · s.
Step A: Rotate a roll mold having an outer peripheral surface on which a plurality of concave microlens transfer portions are arranged, and run the substrate along the outer periphery of the roll mold in the rotation direction of the roll mold while rotating the outer periphery of the roll mold Step of applying the mixture B containing the active energy ray-curable composition B to the surface and filling a part of the microlens transfer portion with the mixture B Step B: Active energy rays between the outer peripheral surface of the roll mold and the substrate Step of supplying the mixture A containing the curable composition A Step C: Region between the outer peripheral surface of the roll mold and the substrate in a state where at least the mixture A is sandwiched between the outer peripheral surface of the roll mold and the substrate. Step of irradiating active energy ray to step Step D: Step of peeling the cured product obtained in Step C from the roll mold   The viscosity of the mixture B measured with a B-type viscometer at 40 ° C. according to ISO 2555 is 100 mPa · s to 4500 mPas than the viscosity of the mixture A measured with a B-type viscometer at 40 ° C. according to ISO 2555. · S Small optical film manufacturing method.   The manufacturing method of the optical film of Claim 1 or 2 whose viscosity of the mixture A measured with the B-type viscometer at 40 degreeC based on ISO2555 is 650 mPa * s-5000 mPa * s.   The method for producing an optical film according to any one of claims 1 to 3, wherein the content of the fine particles in the mixture B is 0 to 35 parts by mass with respect to 100 parts by mass of the active energy ray-curable composition B. .   The manufacturing method of the optical film in any one of Claims 1-4 whose contact angle with the roll type | mold of the active energy ray curable composition B is 30 degrees-80 degrees.   The manufacturing method of the optical film in any one of Claims 1-5 in which the active energy ray-curable composition B contains a non-crosslinkable monomer, a crosslinkable monomer, and a polymerizable initiator.   The optical film obtained by the manufacturing method of the optical film of Claims 1-6.   A surface light emitter comprising the optical film according to claim 7 and an EL element.