WO2010004753A1

WO2010004753A1 - Film in which refractive index modulation is recorded

Info

Publication number: WO2010004753A1
Application number: PCT/JP2009/003205
Authority: WO
Inventors: 靖高松; 祐五山本; 祐一伊東
Original assignee: 三井化学株式会社
Priority date: 2008-07-10
Filing date: 2009-07-09
Publication date: 2010-01-14
Also published as: TWI456785B; KR101278860B1; JP5315344B2; JPWO2010004753A1; KR20100124831A; TW201004002A

Abstract

Provided is a film in which refractive index modulation is recorded, namely, a film that has a refractive index distribution. Specifically, the film has a first region having a first refractive index and second regions having a second refractive index, the second regions are dispersed in the first regions in a manner such that on the surface of the film in which refractive index modulation is recorded, the average value of the circle equivalent diameter of the second regions is from 5 μm to 500 μm, the average value of the spacing between the second regions is 5 μm to 500 μm, and the difference (Δn) between the refractive indices of the first regions and the second regions is 0.001 to 2.0. The film can be manufactured without the need for etching or other complicated processing.

Description

Film with recorded refractive index modulation

The present invention relates to a film on which refractive index modulation is recorded, a method for manufacturing the film, and a light emitting device including the film.

Optical elements such as microlenses are widely applied to CCDs, CMOS optical devices, organic ELs, LED light-emitting devices, etc., or applications are being studied. Usually, in order to form a lens on an optical device or a light emitting device, it is necessary to perform processing such as etching. For example, in order to form a convex lens on an optical device or a light emitting device, deep etching must be applied to the part other than the lens part in order to reduce the radius of curvature of spherical processing, and the processed layer is very thick. Must grow.

Therefore, some diffractive optical elements such as planar Fresnel lenses that are not convex lenses are formed on the light emitting surface, but processing by lithography, etching, etc. is required, and very advanced etching techniques are required. Various methods have been proposed to avoid the etching process, but there are still problems in terms of practicality.

Although a method for producing a refractive index distribution without using etching is disclosed (see Patent Document 1), thermal baking at 250 ° C. to 450 ° C. is performed in the final step of forming an MSQ (Methyl Silsesquioxane) film by a polysilazane method. Necessary and not applicable to heat-sensitive elements.

A method of manufacturing a gradient index lens using two types of monomers is disclosed (see Patent Document 2), which is a two-step process using radical polymerization, and the substrate is immersed in styrene in the second step. However, a complicated process of polymerization is required.

Although a method for manufacturing a microlens array is disclosed (see Patent Document 3), there are a photoresist process and a process for heating to a thermal deformation temperature. When a normal photoresist material is used, a heating process at 150 ° C. or higher. It cannot be used for heat-sensitive elements.

Although a method of forming a microlens by spraying a liquid material is disclosed (Patent Document 4), it is necessary to control the hydrophilicity and hydrophobicity of the substrate and the liquid material. Therefore, it is necessary to apply a hydrophobic layer made of a fluorine-based material to the substrate, and the process is complicated and there is a concern of contamination to other members.

On the other hand, a method for producing a hologram by exposing and heat-treating a photosensitive recording material comprising a thermosetting epoxy oligomer, a radically polymerizable aliphatic monomer, a photoinitiator, and a sensitizing dye (patent) And a photosensitive composition comprising a radical polymerizable compound, a cationic polymerizable compound, a binder polymer, a photosensitizing dye, and a photo cationic polymerization initiator, and exposure with a first light, A method of manufacturing a hologram by performing exposure with second light (see Patent Document 6) has been reported.

Further, by exposing a composition containing two types of photocurable resins having different curable wavelengths with the first light to form a core portion, and further exposing with another light to form a cladding portion. A method for manufacturing an optical waveguide has been reported (see Patent Documents 7 and 8).

JP 2005-57239 A JP-A-5-224305 JP-A-6-194502 JP 2006-23683 A JP-A-7-261640 JP 2004-138686 A JP 2000-347043 A JP 2003-177259 A

An object of the present invention is to provide a film in which refractive index modulation is recorded, that is, a film having a refractive index distribution, without requiring a complicated processing technique such as etching. In particular, the present invention is to provide an optical resin film having a high function such as control of directivity of light. The control of light directivity means the property of controlling the traveling direction of light in a desired direction. If the directivity of light can be controlled, the light extraction efficiency from the light emitting device can be increased.

That is, the first of the present invention relates to the following films.
[1] A film having a first region having a first refractive index and a second region having a second refractive index, and the second region is dispersed in the first region,
On the film surface, the average value of the equivalent circle diameter of the second region is 5 μm or more and 500 μm or less, and the average value of the interval between the second regions is 5 μm or more and 500 μm or less,
A film in which a difference in refractive index (Δn) between the first region and the second region is 0.001 to 2.0.

[2] The film according to [1], wherein the surface roughness Ra measured by AFM (atomic force microscope) is 0.01 to 1 μm.
[3] The film according to [1], wherein the second region is substantially cylindrical.
[4] The film according to claim 1, wherein the refractive index is odorally modulated from the first region to the second region.
[5] The film according to [1], which is a gradient index microlens.
[6] The film according to [1], wherein any one of the first region and the second region includes a resin having a fluorene skeleton.
[7] The film according to [1], wherein one of the first region and the second region contains an epoxy resin.

The second of the present invention relates to a composition for refractive index modulation recording shown below and a method for producing a film on which refractive index modulation is recorded.
[8] An acrylic compound having a refractive index of nD [A]; an epoxy compound having a refractive index of nD [B] and having no photo-radically polymerizable functional group; a photo-radical initiator; A composition comprising:
| ND [B] −nD [A] | is 0.001 or more and 2.0 or less,
A composition for refractive index modulation recording, wherein the viscosity at 25 ° C. measured with an E-type viscometer is 0.01 to 100 Pa · s.
[9] The composition according to [8], wherein the acrylic compound has a fluorene skeleton, and the molecular weight of the acrylic compound is 100 or more and 1000 or less.
[10] The composition according to [8], further comprising a thermal radical initiator.
[11] The composition according to [8], which is in a film form.

[12] A first step of preparing the composition according to [8], a second step of selectively irradiating the composition with active energy rays, and a composition irradiated with the active energy rays A method for producing a film on which a refractive index modulation is recorded, comprising:
The film recording the refractive index modulation is
A first region having a first refractive index and a second region having a second refractive index, and the second region is dispersed in the first region;
On the film surface of the film, the average value of the equivalent circle diameter of the second region is 5 μm or more and 500 μm or less, and the average value of the interval between the second regions is 5 μm or more and 500 μm or less,
The manufacturing method, wherein a difference in refractive index (Δn) between the first region and the second region is 0.001 to 2.0.
[13] The manufacturing method according to [12], wherein in the first step, the composition is disposed in a thin film on the organic EL element.
[14] A film on which a refractive index modulation is recorded, comprising: a first step of preparing the composition according to [8]; and a second step of selectively irradiating the composition with active energy rays. A manufacturing method comprising:
The film recording the refractive index modulation is
A first region having a first refractive index and a second region having a second refractive index, and the second region is dispersed in the first region;
On the film surface, the average value of the equivalent circle diameter of the second region is 5 μm or more and 500 μm or less, and the average value of the interval between the second regions is 5 μm or more and 500 μm or less,
The manufacturing method, wherein a difference in refractive index (Δn) between the first region and the second region is 0.001 to 2.0.

The third of the present invention relates to a light emitting device and a method for manufacturing the same.
[15] A panel substrate on which the organic EL element is disposed, a counter substrate paired with the panel substrate, a seal layer interposed between the panel substrate and the counter substrate, and sealing the organic EL element; A light emitting device comprising:
The sealing layer is
A first region having a first refractive index and a second region having a second refractive index, and the second region is dispersed in the first region;
The average equivalent circle diameter of the second region on the surface of the seal layer is 5 μm or more and 500 μm or less, and the average value of the interval between the second regions is 5 μm or more and 500 μm or less,
The light emitting device, wherein a difference in refractive index (Δn) between the first region and the second region is 0.001 to 2.0.
[16] A method for producing the light-emitting device according to [15], comprising the step of adhering the film according to [1] to an organic EL element; and the step of curing the adhered film. Manufacturing method of light-emitting device.

The film on which the refractive index modulation of the present invention is recorded can have a function of controlling the directivity of light even though it can be manufactured without requiring a complicated process such as etching. Therefore, the film of the present invention can enhance the light extraction efficiency, for example, and can increase the light extraction efficiency of the device when used as a member of a light emitting device (for example, an organic electroluminescent element).

In the film of the present invention, a desired refractive index distribution can be formed, and for example, a cylindrical, concentric, or lattice-shaped refractive index distribution can be formed. In the film of the present invention, high refractive index regions and low refractive index regions can be alternately formed. Films recorded with such refractive index modulation can achieve the same effect as a light-emitting device equipped with a Fresnel lens, and the light from the light-emitting device is condensed or dispersed and taken out to the outside. You can also.

Of course, since the film on which the refractive index modulation of the present invention is recorded can be manufactured by a simple manufacturing process, a light emitting device including the film can be thinned and miniaturized. Furthermore, since the film of the present invention is substantially composed of an organic material, it is less in weight than a film having a skeleton formed of an inorganic material and can be suitably used as a sealing member for a light-emitting device such as an organic EL element. it can.

It is a figure which shows typically the typical example of the film on which refractive index modulation was recorded. It is a figure which shows the photomask used in Example 1. FIG. 3 is a refractive index modulation map of a film on which refractive index modulation obtained in Example 1 is recorded.

The film of the present invention is a film-like member made of substantially organic material, and may be a single film or a thin film or layer formed on any substrate (including a light emitting element). “Substantially composed of an organic substance” means that a skeleton is formed by a carbon-carbon bond within a range not reducing the effect of the present invention, and the shape of the member is maintained. Although the refractive index modulation is recorded, the film of the present invention is not a member that forms optical interference fringes such as a hologram, and is a member that does not have wavelength dependency.

The film of the present invention has a first region having a first refractive index and a second region having a second refractive index. The first region acts as a base material, and the second region is dispersed in the first region.

The difference between the first refractive index and the second refractive index may be 0.001 to 2.0, and is preferably 0.01 to 2.0. The first refractive index and the second refractive index need only be different, and any of them may be large. Further, from the viewpoint of ease of production of the film of the present invention, the difference between the first refractive index and the second refractive index is preferably 0.001 to 1.0, more preferably 0.001 to 0.5. . The difference in refractive index can be the difference between the maximum refractive index in the region with the higher refractive index and the minimum refractive index in the region with the lower refractive index. The refractive index may be measured using an interference microscope. Specifically, it is measured with reference to the measurement principle described in “APPLIED OPTICS, vol.41, No.7, 1308 (2002)” as described in the examples described later.

As described above, it is preferable that the film of the present invention does not have wavelength dependency (does not form interference fringes or diffraction gratings). Therefore, it is preferable that the second region dispersed in the first region has a certain size. Specifically, the average value of the equivalent circle diameter of the second region on the surface of the film is preferably 5 μm or more and 500 μm or less. Moreover, it is preferable that the average of the space | interval of 2nd area | regions on the surface of a film is 5 micrometers or more and 500 micrometers or less. If the average value of the equivalent circle diameters of the second regions and the average of the intervals between the second regions are smaller than 5 μm, interference fringes may be formed.

As will be described later, the refractive indexes of the first region and the second region may be modulated in a gradient manner. In that case, the boundary between the first region and the second region on the film surface is arbitrarily set to a region where the refractive index is gradient-modulated; on the basis of the set boundary, What is necessary is just to obtain | require the magnitude | size (circle equivalent diameter) and the space | interval of 2nd area | regions.

When the film of the present invention is used as a microlens, it is preferable that the second region penetrates the first region, that is, the second region penetrates in the thickness direction of the film. If the second region penetrates, the light direction can be controlled in the penetrating direction, and the light directivity can be obtained. If the penetrating second region has a substantially cylindrical shape, the formation of interference fringes is suppressed.

In order to increase the light extraction efficiency using the film of the present invention, the second region is preferably arranged in a matrix (lattice) in the first region.

FIG. 1 schematically shows a representative example of the film of the present invention. The first region A having the first refractive index constitutes the base material of the film. The second region B having the second refractive index is arranged in a matrix (lattice) on the film surface. Each second region B has a substantially cylindrical shape and penetrates in the thickness direction of the film. The equivalent circle diameter b on the film surface in the second region B is set to about 5 to 500 μm. The shortest distance a between the second regions B is also set to about 5 to 500 μm.

The surface of the film of the present invention is preferably flat. Although the film of this invention may be installed in the panel board | substrate or the element on a panel board | substrate, it is for making arrangement | positioning easy. Specifically, the surface roughness Ra of the film is usually 0.01 to 1 μm, preferably 0.01 to 0.1 μm. As described later, since the film of the present invention does not need to be processed by etching or the like, the film surface can be made flat.

In the case where the film of the present invention is provided in a light transmission portion of a light emitting device (for example, an organic EL light emitting element) to increase luminous efficiency, the thickness is preferably 1 to 200 μm, and preferably 1 to 100 μm. More preferably. Further, when a film in which refractive index modulation is recorded is used as a microlens (refractive index distribution type lens), the lens function can be adjusted by the film thickness. Therefore, what is necessary is just to adjust film thickness according to a desired lens function.

Any one of the first region and the second region constituting the film of the present invention is preferably a resin containing a fluorene skeleton. By introducing a fluorene skeleton, the refractive index can be increased. Therefore, if one of the first region and the second region is a resin containing a fluorene skeleton, a difference in refractive index from the other region is likely to occur.

Also, either one of the first region and the second region constituting the film of the present invention may contain an epoxy resin. As described later, the film of the present invention is obtained by photopolymerizing a composition containing a photopolymerizable resin and a thermosetting resin (epoxy resin), but the thermosetting resin is in an uncured state. (Half-cure film) is also an embodiment of the film of the present invention. Of course, the film in which the thermosetting resin is cured is also an embodiment of the film of the present invention.

The film on which the refractive index modulation of the present invention is recorded can be used as an optical device for any application. For example, it can be used as a microlens for an optical element. When a film on which refractive index modulation is recorded is used as a lens, it is preferable that the refractive index changes in a gradient from the first region to the second region.

The lens is a transparent body that shows the refractive action of light, and can control the direction of light passing through it. For example, it can diffuse or focus light. Unlike the spherical lens, the lens in the present invention is referred to as a gradient index lens. The gradient index lens refers to a transparent member that is gradient-modulated from a certain point toward the periphery. That is, when a film on which refractive index modulation is recorded is used as a gradient index lens, it is preferable that the refractive index of the first region or the second region changes in a gradient manner.

In particular, when the cylindrical second region passes through the first region serving as the base material, if the refractive index of the second region is gradiently modulated in the radial direction, the gradient index rod It can be used as a lens. At that time, if the second region is dispersed in a matrix, it can be used as a gradient index rod lens array (see FIG. 1).

Since the light incident from the lens end face of the gradient index rod lens travels while drawing a sine curve, it is possible to obtain an equal-magnification erect image by adjusting the rod length (here, the thickness of the film thickness). . Therefore, the gradient index rod lens (array) can be used as a lens for facsimile, scanner, copying machine, electronic blackboard, LED printer, and optical fiber communication.

Furthermore, if the film on which the refractive index modulation of the present invention is recorded is used, it is possible to efficiently extract light emitted from the light emitting device. Therefore, the luminous efficiency of the light emitting device can be increased by providing the film on which the refractive index modulation of the present invention is recorded in the passage portion of the light emitted from the light emitting device.

It is said that the light extraction efficiency of the top emission type organic electroluminescence device is about 20%. One of the causes of the decrease in the light extraction efficiency is reflection at the interface between the organic electroluminescent element and the sealing film that seals it; reflection at the interface between the sealing film and the glass substrate on the outside It is in. The sealing film prevents moisture and oxygen from entering the organic electroluminescent element, and may be made of a resin or the like.

Therefore, by using the sealing film for sealing the top emission type organic electroluminescent element as a film recording the refractive index modulation of the present invention, it is possible to obtain sealing properties and further increase the light extraction efficiency. . That is, by controlling the traveling direction of light emitted from the light emitting layer of the organic electroluminescent element with the film of the present invention, reflection at the interface with the glass substrate is suppressed, and light extraction efficiency is increased.

For example, the organic electroluminescent element disposed on the panel substrate is heated by applying the “half-cure film (a film obtained by photopolymerization)” to form a sealing film of the organic electroluminescent element. A film in which a refractive index modulation is recorded can also be formed. A counter substrate is disposed on the film.

The film recording the refractive index modulation according to the present invention includes: 1) a step of preparing a composition (a composition for refractive index modulation recording) containing a photopolymerizable resin and a thermosetting resin; and 2) a composition. Irradiating active energy rays in a position-selective manner, and 3) heating.

The photopolymerizable resin contained in the composition for refractive index modulation recording preferably contains an acrylic compound. The acrylic compound is not particularly limited as long as it is a compound containing an acrylic group or a methacryl group, but preferably has a fluorene skeleton. As described above, the refractive index can be easily increased by introducing a fluorene skeleton. If the refractive index can be increased, the difference in refractive index from the epoxy compound contained in the thermosetting resin described later can be increased. The refractive index can be increased by introducing sulfur element or halogen element into the resin. In order to maintain transparency, it is preferable to introduce sulfur element.

Examples of acrylic compounds having a fluorene skeleton include 9,9-bis (4- (meth) acryloyloxyphenyl) fluorene; 9,9-bis (4- (meth) acryloyloxymethoxyphenyl) fluorene; Bis [4- (2- (meth) acryloyloxyethoxy) phenyl] fluorene; 9,9-bis [4- (meth) acryloyloxy-3-methylphenyl] fluorene; 9,9-bis [4- (meth) Acryloyloxymethoxy-3-methylphenyl] fluorene; 9,9-bis [4- (2- (meth) acryloyloxyethoxy) -3-methylphenyl] fluorene; 9,9-bis (4- (meth) acryloyloxy -3-ethylphenyl) fluorene; 9,9-bis (4- (meth) acryloyloxymethoxy-3-ethylphenyl) fluorene; 9,9-bis [4- (2- (meta ) Acryloyloxyethoxy) -3-ethylphenyl] fluorene; 9,9-bis [4- (2- (meth) acryloyloxypropoxy) -3-ethylphenyl] fluorene; 9,9-bis [4- (3- (Meth) acryloyloxy-2-hydroxy) propoxyphenyl] fluorene; 9,9-bis [4- (3- (meth) acryloyloxy-2-hydroxy) propoxy-3-methylphenyl] fluorene; 9,9-bis {4- [2- (3-acryloyloxy-2-hydroxy-propoxy) -ethoxy] phenyl} fluorene and the like are included.
The acrylic compound having a fluorene skeleton may be a dimer or trimer oligomer of the above exemplary compounds.

The molecular weight of the acrylic compound is preferably 100 or more and 1000 or less. This is for imparting a certain degree of photopolymerization reactivity to the acrylic compound.

The photopolymerizable resin preferably contains a photo radical initiator. The type of the photo radical initiator is not particularly limited, and may be appropriately selected according to the type of the acrylic compound. Examples of photo radical initiators include benzoin compounds, acetophenones, benzophenones, thioxanthones, α-acyloxime esters, phenylglyoxylates, benzyls, azo compounds, diphenyl sulfide compounds, acylphosphine oxides Compounds, organic dye compounds, iron-phthalocyanine compounds, benzoins, benzoin ethers, anthraquinones, and the like.

The amount of the photo radical initiator contained in the photopolymerizable resin is preferably 0.1 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the acrylic compound.

On the other hand, the thermosetting resin contained in the composition for refractive index modulation recording preferably contains an epoxy compound. The epoxy compound is required not to have photoradical polymerizability. Therefore, the epoxy compound preferably does not have a photoradically polymerizable functional group such as a carbon-carbon unsaturated bond (such as an acrylic group).

The thermosetting resin preferably contains a thermosetting accelerator. The kind of thermosetting accelerator is not specifically limited, What is necessary is just to select suitably according to the kind of epoxy compound. Examples of the thermosetting accelerator include imidazole compounds and amine compounds. Examples of the imidazole compound include 2-ethyl-4-methylimidazole. Examples of the amine compound include trisdimethylaminomethylphenol. The amount of the thermosetting accelerator contained in the thermosetting resin is preferably 0.1 to 100 parts by mass with respect to 100 parts by mass of the epoxy compound.

The thermosetting resin may contain an acid anhydride. From the thermosetting resin containing an acid anhydride, a highly transparent resin cured product is obtained. The acid anhydride contained in the thermosetting resin is required not to have photopolymerizability, and therefore does not have a photopolymerizable functional group. The acid anhydride is preferably an aromatic carboxylic acid anhydride, and examples of the acid anhydride include phthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, Hydrophthalic anhydride, trimellitic anhydride, hexachloroendomethylenetetrahydrophthalic anhydride, benzophenone tetracarboxylic anhydride and the like are included.

The thermosetting resin may contain a thermal radical initiator. The thermal radical initiator prevents the photopolymerizable compound from finally remaining by polymerizing the photopolymerizable compound that is not polymerized by light irradiation, which will be described later, by heating. Examples of the thermal radical initiator include conventionally known organic peroxides and azo compounds. Although it depends on the heating conditions, the thermal radical initiator is preferably a compound having a 10-hour half-life temperature of 120 ° C. or lower. Examples of thermal radical initiators include cumyl peroxyneodecanoate, di-n-propyl peroxydicarbonate, di (2-ethylhexyl) peroxydicarbonate, t-butylperoxyneodecanoate, 2, 4-dichlorobenzoyl peroxide, lauroyl peroxide, acetyl peroxide, t-butylperoxy-2-ethylhexanoate, benzoyl peroxide, t-butylperoxyisobutyrate, t-butylperoxylaurate, t -Butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxyisopropyl carbonate, t-butylperoxyacetate, t-butylperoxybenzoate, methyl ethyl ketone peroxide, dicumyl peroxide, t-butyl Such as cumyl peroxide. . Examples of the azo compound include azobisisobutyronitrile, 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), azobis (methylbutylnitrile), and the like. In the present invention, one type of thermal radical initiator may be used, or two or more types may be used in combination.

The composition of the present invention includes a photopolymerizable resin containing an acrylic compound and a thermosetting resin containing an epoxy compound, but the refractive index nD [A] of the acrylic compound and the refractive index nD [B] of the epoxy compound. It is preferable that the difference is 0.001 or more and 2.0 or less. When the acrylic compound or the epoxy compound is a mixture of two or more compounds, the refractive index of the mixture is nD [A] or nD [B].

Either nD [A] or nD [B] may be large. However, as described above, when a fluorene skeleton is introduced into the acrylic compound, nD [A] increases, and therefore it is preferable to satisfy nD [A]> nD [B].

The composition for refractive index modulation recording of the present invention contains a photopolymerizable resin containing an acrylic compound and a thermosetting resin containing an epoxy compound, but the content of the epoxy compound with respect to 100 parts by mass of the acrylic compound is 10 It is preferable that it is not less than 1000 parts by mass.

The viscosity of the composition for refractive index modulation recording is not particularly limited, but in the step of irradiating active energy rays, which will be described later, the photopolymerizable resin moves to the irradiation region and polymerizes selectively in the irradiation region. It is preferable to do so. If the viscosity of the composition is too high, the movement of the photopolymerizable resin to the irradiation region is suppressed; if the viscosity is too low, the photopolymerizable resin that has moved to the irradiation region does not stay in the irradiation region, but is position-selective. Not polymerized. Therefore, the viscosity (25 ° C.) measured by an E-type viscometer of the composition is preferably 0.01 to 100 Pa · s, and more preferably 0.01 to 50 Pa · s.

The method for producing a film on which refractive index modulation is recorded according to the present invention includes a step of selectively irradiating the above-mentioned composition with active energy rays. The active energy ray to be irradiated may be an energy ray capable of polymerizing the photopolymerizable resin. Examples of active energy rays include ultraviolet rays, electron beams, visible rays, infrared rays, and the like.

The composition irradiated with the active energy ray is preferably formed into a thin film. The thin film composition is a film composition, a coating film of a composition formed on a substrate, or a thin film composition sandwiched and held between two glass plates. Or When sandwiching and holding between two glass plates, a release film may be disposed between the glass plate and the thin film, whereby the single film can be easily taken out. The thickness of the thin film composition may be adjusted so that the film thickness after irradiation with active energy rays is 1 to 200 μm. When the thickness of the thin film composition is too thick, light is not sufficiently propagated into the film, and the recording property of the refractive index modulation is lowered.

In order to selectively irradiate the active energy rays, the composition may be irradiated with a mask on which a desired pattern is formed, or may be irradiated by scanning.

Although the area of each irradiation region is arbitrary, it is preferable that the film on which the refractive index modulation of the present invention is recorded does not form an interference fringe and does not have wavelength dependency. The equivalent diameter is preferably 5 μm or more and 500 μm or less. Further, the shape of the opening of the mask (the shape of the irradiation region) is preferably circular. If the shape has a vertex (triangle or square), the vertex may form an interference fringe.

When the active energy ray is selectively irradiated to the thin film composition, the photopolymerizable resin is polymerized in the irradiated region. Then, unpolymerized photopolymerizable resin existing around the irradiation region flows into the irradiation region, and thermosetting resin existing in the irradiation region flows out from the irradiation region. The photopolymerizable resin that has flowed into the irradiated region is also polymerized by active energy rays.

In this way, a film in which the photopolymerized resin is selectively unevenly distributed in the irradiated region is obtained. This film may be referred to as a “half-cure film”, and the half-cure film is also an embodiment of the film of the present invention.

The obtained half-cure film mainly contains an uncured thermosetting resin outside the irradiation region. Therefore, the thermosetting resin is cured by heating the half cure film. At this time, if the thermosetting resin contains a thermal radical initiator, a part of the photopolymerizable resin that could not be polymerized by light irradiation can also be thermally polymerized, and the monomer remains in the resulting film. Can also be prevented.

By heating the half-cure film, a film in which the polymer of the photopolymerizable resin is unevenly distributed in the irradiated region and the cured product of the thermosetting resin is unevenly distributed in the other region is obtained. As described above, since there is a difference between the refractive index of the acrylic compound contained in the photopolymerizable resin and the refractive index of the epoxy compound contained in the thermosetting resin, the refractive index of the photopolymerized resin and the heat The refractive index of the cured resin also has almost the same difference. As a result, a film in which the refractive index modulation is recorded is obtained.

Each component used in each example and comparative example is as follows.

Components of photopolymerizable resin Fluorene type acrylate resin: 9,9-bis (4- (meth) acryloyloxyphenyl) fluorene (Ogsol EA-0200, manufactured by Osaka Gas Chemical Company)
Acrylate resin (without fluorene skeleton): Triethylene glycol dimethacrylate Photoinitiator: Irgacure 651 (Ciba Specialty Chemicals)

Components of thermosetting resin Bisphenol F type epoxy resin; YL-983U (manufactured by Japan Epoxy Resin Co., Ltd.)
Thermosetting accelerator: Trisdimethylaminomethylphenol (JER Cure 3010, manufactured by Japan Epoxy Resin Co., Ltd.)
Acid anhydride (curing agent): Mixture of hexahydrophthalic anhydride and methylhexahydrophthalic anhydride (Licacid MH-700, manufactured by Shin Nippon Rika Co., Ltd.)
Thermal initiator: Perbutyl O (manufactured by NOF Corporation)

<Test piece preparation>
The composition prepared in each Example or Comparative Example was sandwiched between two glass plates (60 × 60 × 1.3 mm) and fixed with Kapton tape to obtain a test piece. By placing an aluminum foil spacer between the two glass plates, the thickness of the test piece was set to 12 μm.

<Recording of refractive index modulation>
The produced test piece was exposed for 60 seconds at a light intensity of 10 mW / cm ² using a UV irradiation machine (LIGHTNINGCURE LC8 manufactured by Hamamatsu Photonics) with a photomask (see FIG. 2) interposed. As shown in FIG. 2A, the used photomask is a member in which holes are provided in a matrix shape in a central region (10 × 10 mm) of 50 mm × 50 mm. As shown in FIG. 2B, the hole diameter is 30 μm, the distance between the centers of the holes is 37.6 μm, and the distance between the holes is 7.6 μm.

Thereafter, the test piece was after-cured for 2 hours in an oven at 80 ° C. to obtain a film on which the refractive index modulation was recorded.

<Evaluation>
The composition obtained in each example or comparative example and the film on which the refractive index modulation was recorded were evaluated for the following items.

(1) Transparency The composition is visually observed to be a transparent and uniform solution, and the film on which the refractive index modulation is recorded is also visually observed. The case of white turbidity was evaluated as x.
(2) Viscosity The viscosity of the composition at 25 ° C. was measured using an E-type viscometer (Digital Rheometer Model DII-III ULTRA manufactured by BROOKFIEL).
(3) Recordability It was observed with an optical microscope whether the shape of the hole of the mask was recorded on the film. The case where it was recorded was marked with ◯, the case where it was recorded but partially recorded was marked with △, the case where it was slightly recorded was marked with △, and the case where it was not recorded was marked with ×.
(4) Refractive index modulation of film recording refractive index modulation Refractive index modulation (refractive index of irradiated region and non-irradiated region) by interference microscope (transmission type phase shift laser microscopic interference measuring device, FK Optical Research Laboratory) (Difference from the refractive index). The incident light was a He—Ne laser (wavelength: 633 nm). The principle of this measurement is described in APPLIED OPTICS, vol.41, No.7, 1308 (2002). The difference Δn in the refractive index is a value of the difference between the maximum refractive index and the minimum refractive index in the film on which the refractive index modulation is recorded.

Example 1
50 parts by mass of Ogsol EA-0200, 25 parts by mass of YL-983U, and 25 parts by mass of Rikacid MH-700 were charged into a flask and mixed while heating. Thereafter, the temperature was lowered to room temperature, and 3 parts by mass of Irgacure 651 and 0.5 parts by mass of perbutyl O were added and mixed. Furthermore, 1 part by mass of JER Cure 3010 was added and stirred at room temperature to obtain a composition. A test piece was prepared from the obtained composition, and the refractive index modulation was further recorded to produce a film on which the refractive index modulation was recorded.

Examples 2-5
A film in which the refractive index modulation was recorded was obtained in the same manner as in Example 1 except that the blending ratio (part by mass) of each component was as shown in the following table.

The following table shows the evaluation results of the compositions prepared in Examples 1 to 5 and the film on which the refractive index modulation was recorded.

Moreover, the surface roughness of the glass plate used for test piece preparation was measured by AFM. The center line average roughness Ra was 0.01 μm, and the maximum height Rmax was 0.35 μm. The surface roughness of the glass was transferred to the surface of the produced film, and had the same degree of roughness.

Furthermore, a map of refractive index modulation of the film on which the refractive index modulation obtained in Example 1 is recorded is shown in FIG. It can be seen that the portions having different refractive indexes (high refractive index) are arranged in a matrix.

Examples 6-7
Example 1 except that “triethylene glycol dimethacrylate”, which is an acrylate resin having no fluorene structure, was used instead of Ogsol EA-0200, and the blending ratio of each component was as shown in the following table. In the same manner as described above, a film on which refractive index modulation was recorded was obtained.

In Examples 6 and 7, the evaluation result of the recordability was Δ. This is presumably because the difference in refractive index did not increase because the acrylate resin used as the photopolymerizable resin did not contain a fluorene skeleton.

This application claims priority based on application number JP2008-180578 (Japanese Patent Application No. 2008-180578) filed on Jul. 10, 2008. The contents described in the application specification and the drawings are all incorporated herein.

The refractive index modulation recording film of the present invention can have functions such as controlling the directivity of light. Therefore, the refractive index modulation recording film of the present invention can increase the light extraction efficiency, for example, and can increase the light extraction efficiency of the device when used as a member of a light emitting device (for example, an organic electroluminescent element).

Claims

A film having a first region having a first refractive index and a second region having a second refractive index, wherein the second region is dispersed in the first region;
On the film surface, the average value of the equivalent circle diameter of the second region is 5 μm or more and 500 μm or less, and the average value of the interval between the second regions is 5 μm or more and 500 μm or less,
A film in which a difference in refractive index (Δn) between the first region and the second region is 0.001 to 2.0.
2. The film according to claim 1, wherein the surface roughness Ra measured by AFM (atomic force microscope) is 0.01 to 1 μm.
The film according to claim 1, wherein the second region is substantially cylindrical.
The film according to claim 1, wherein the refractive index is odorically modulated from the first region to the second region.
The film according to claim 1, which is a refractive index distribution type microlens.
The film according to claim 1, wherein one of the first region and the second region contains a resin having a fluorene skeleton.
The film according to claim 1, wherein one of the first region and the second region contains an epoxy resin.
An acrylic compound having a refractive index of nD [A];
An epoxy compound having a refractive index of nD [B] and having no photo-radically polymerizable functional group;
A photo radical initiator;
A thermosetting accelerator, comprising:
| ND [B] −nD [A] | is 0.001 or more and 2.0 or less,
A composition for refractive index modulation recording, wherein the viscosity at 25 ° C. measured with an E-type viscometer is 0.01 to 100 Pa · s.
The composition according to claim 8, wherein the acrylic compound has a fluorene skeleton, and the molecular weight of the acrylic compound is from 100 to 1,000.
The composition according to claim 8, further comprising a thermal radical initiator.
The composition according to claim 8, which is in the form of a film.
A first step of preparing the composition according to claim 8, a second step of site-selectively irradiating the composition with active energy rays, and heating the composition irradiated with the active energy rays. A method for producing a film on which a refractive index modulation is recorded, comprising:
The film recording the refractive index modulation is
A first region having a first refractive index and a second region having a second refractive index, and the second region is dispersed in the first region;
On the film surface, the average value of the equivalent circle diameter of the second region is 5 μm or more and 500 μm or less, and the average value of the interval between the second regions is 5 μm or more and 500 μm or less,
The manufacturing method, wherein a difference in refractive index (Δn) between the first region and the second region is 0.001 to 2.0.
The manufacturing method according to claim 12, wherein, in the first step, the composition is disposed in a thin film shape on the organic EL element.
A method for producing a film on which refractive index modulation is recorded, comprising: a first step of preparing the composition according to claim 8; and a second step of position-selectively irradiating the composition with active energy rays. There,
The film recording the refractive index modulation is
A first region having a first refractive index and a second region having a second refractive index, and the second region is dispersed in the first region;
On the film surface, the average value of the equivalent circle diameter of the second region is 5 μm or more and 500 μm or less, and the average value of the interval between the second regions is 5 μm or more and 500 μm or less,
The manufacturing method, wherein a difference in refractive index (Δn) between the first region and the second region is 0.001 to 2.0.
A panel substrate on which the organic EL element is disposed, a counter substrate that is paired with the panel substrate, and a seal layer that is interposed between the panel substrate and the counter substrate and seals the organic EL element. A light emitting device,
The sealing layer is
A first region having a first refractive index and a second region having a second refractive index, and the second region is dispersed in the first region;
The average equivalent circle diameter of the second region on the surface of the seal layer is 5 μm or more and 500 μm or less, and the average value of the interval between the second regions is 5 μm or more and 500 μm or less,
The light emitting device, wherein a difference in refractive index (Δn) between the first region and the second region is 0.001 to 2.0.
A method for manufacturing the light emitting device according to claim 15, comprising:
A method for manufacturing a light emitting device, comprising: a step of adhering the film according to claim 1 to an organic EL element; and a step of curing the adhered film.