JP5298692B2 - Organic electroluminescence light source device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL light source device suppressed in change of color due to an observation angle. <P>SOLUTION: This organic electroluminescent light source device is provided with an organic electroluminescent light emitting element, and a selective reflection layer. The organic electroluminescent light source device is characterized in that the organic electroluminescent light emitting element includes an organic luminescent layer having two or more emission intensity peaks; and the selective reflection layer includes a peak wavelength of at least one of the emission intensity peaks in a selective reflection band of transmitted light in its front direction. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an organic electroluminescence (hereinafter sometimes abbreviated as “organic EL”) light source device.

  An organic EL device that provides an organic light emitting layer between multiple layers of electrodes to obtain light emission is used as a display device instead of a liquid crystal cell, as well as its high luminous efficiency, low voltage drive, light weight, low cost, etc. Utilization of the above features is also being considered for use as a planar light source such as a flat illumination and a backlight for a liquid crystal display device.

  When an organic EL element is used as a surface light source, it is a problem to increase the light extraction efficiency. That is, although the light emitting layer itself of the organic EL element has high luminous efficiency, the light amount is reduced by interference in the layer until it emits light through the laminated structure constituting the element. Such light loss is required to be reduced as much as possible.

  As a method for increasing the light extraction efficiency, for example, in Patent Document 1, the luminance in the front direction (0 °) of the element is suppressed and the luminance at an angle of 50 to 70 ° is increased, thereby increasing the overall luminance. It is disclosed.

  By the way, when using an organic EL element for a surface light source, in addition to the improvement of light extraction efficiency, it becomes a further subject to reduce the change of the tint by an observation angle. That is, when the light spectrum changes between when the surface light source is observed from the front direction and when observed from the oblique direction, a change in color depending on the observation angle occurs, which is not preferable as a light source.

JP 2004-296423 A

  An object of the present invention is to provide an organic EL light source device in which a change in color depending on an observation angle is suppressed.

As a result of studies conducted by the inventors of the present invention in order to solve the above problems, it has been found that the above problems can be solved by providing a selective reflection layer having specific optical characteristics in the organic EL light source device. The invention has been solved.
Therefore, according to the present invention, the following [1] to [7] are provided.

[1] An organic electroluminescence light source device comprising an organic electroluminescence light emitting element and a selective reflection layer, wherein the organic electroluminescence light emitting element has an organic light emitting layer having two or more emission intensity peaks, and the selection The organic electroluminescence light source device, wherein the reflective layer includes at least one peak wavelength of the emission intensity peak in a selective reflection band of transmitted light in the front direction.
[2] The organic electroluminescence light source device, further comprising a light scattering layer.
[3] The organic electroluminescence light source device, further comprising an uneven structure layer.
[4] The organic electroluminescence light source device, wherein the selective reflection layer has a transmittance T ^F _{Y, N in} a front direction at a wavelength of 575 nm and an average value T ^F _{Y in} a transmittance at a polar angle of 60 ° at a wavelength of 575 nm. _{, 60} , the transmittance T ^F _{B, N in} the front direction at a wavelength of 480 nm, and the average value T ^F _{B, 60} of the transmittance in the polar angle 60 ° direction at a wavelength of 480 nm satisfy the relationship of formula [1]. Organic electroluminescence light source device.
_{^{(T F Y, 60 / T}} F Y, N)> (T F B, 60 / T F B, N) formula (1)
[5] The organic electroluminescence light source device, wherein the selective reflection layer has one or more selective reflection bands in a wavelength range of 500 nm to 650 nm as a selective reflection band of transmitted light in a front direction. An organic electroluminescence light source device.
[6] The organic electroluminescence light source device, wherein the selective reflection layer has one or more selective reflection bands in a wavelength range of 400 nm to 550 nm as a selective reflection band of transmitted light in a polar angle of 60 ° direction. An organic electroluminescence light source device.
[7] The organic electroluminescence light source device, wherein the organic electroluminescence light emitting element has a light emission intensity peak in a wavelength range of 550 nm to 600 nm.

  The light source device of the present invention is useful as a light source for a backlight of a liquid crystal display device, an illuminating device, and the like because there is little change in color depending on the viewing angle.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a cross-sectional view showing the layer configuration of the first embodiment of the organic EL light source device of the present invention. In FIG. 1, an apparatus 100 includes a substrate 101, a light emitting element 120 provided on a light incident surface (lower surface in the drawing) of the substrate 101, and a laminate provided on a light emitting surface (upper surface in the drawing) of the substrate 101. 130, and the upper surface 109 of the device is a light exit surface. The laminated body 130 includes a selective reflection layer 131 and a base film 132 in order from the substrate 101 side. The light emitting element 120 includes a transparent electrode 111, a light emitting layer 121, and a reflective electrode 112 in order from the substrate 101 side.

  As the substrate 101, a substrate that can be normally used as a substrate of an organic EL light emitting element, such as a glass substrate, quartz glass, or a plastic substrate, can be employed.

  The light-emitting layer 121 constituting the light-emitting element 120 is not particularly limited and can be appropriately selected from known ones. However, in order to suit the use as a light source, a single layer or a combination of a plurality of layers can be used. It can emit light including a predetermined peak wavelength described later. The transparent electrode 111 and the reflective electrode 112 are not particularly limited, and known ones can be appropriately selected. Further, other layers such as a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, and a gas barrier layer can be further provided between the electrodes in addition to the light emitting layer.

Specific layer configurations of the light-emitting element include anode / hole transport layer / light-emitting layer / cathode configuration, anode / hole transport layer / light-emitting layer / electron injection layer / cathode configuration, anode / hole injection layer / Composition of light emitting layer / cathode, anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode composition, anode / hole transport layer / light emitting layer / electron injection layer / equipotential Structure of surface forming layer / hole transport layer / light emitting layer / electron injection layer / cathode, anode / hole transport layer / light emitting layer / electron injection layer / charge generation layer / hole transport layer / light emitting layer / electron injection layer / Examples include the configuration of the cathode. The light-emitting element in the organic EL light source device of the present invention can have one or more light-emitting layers between the anode and the cathode, and as the light-emitting layer, a laminate of a plurality of layers having different emission colors, or A certain dye layer may have a mixed layer doped with different dyes. The material of each layer is not particularly limited. Examples of the light emitting material include polyparaphenylene vinylene, polyfluorene, and polyvinyl carbazole. Examples of the hole injection layer and the hole transport layer include phthalocyanine-based, arylamine-based, and polythiophene-based materials, and examples of the electron injection layer and the electron transport layer include aluminum complex and lithium fluoride. As the magnetic potential surface forming layer or the charge generation layer, ITO, IZO, the transparent electrode such as SnO _2, or Ag, a metal thin film such as Al and the like.

  The transparent electrode 111, the light emitting layer 121, the reflective electrode 112, and other arbitrary layers constituting the light emitting element can be provided by sequentially laminating them on the substrate 101.

In the present invention, the light emitting layer 121 has two or more light emission intensity peaks. Preferably, one or more of the two or more emission intensity peaks may be in a wavelength range of 500 nm to 650 nm.
An example of the spectrum of the light emitting layer having such a light emission intensity peak is shown in FIG. The spectrum shown in FIG. 3 has two peaks at wavelengths of 480 nm and 575 nm.
For such two or more emission intensity peaks, as described above, the light emitting layer should be a laminate of a plurality of layers having different emission colors, or a mixed layer in which a certain dye layer is doped with a different dye. Can be obtained.

  Next, the selective reflection layer 131 on the substrate 101 will be described. In the present invention, the selective reflection layer is a layer having a property of transmitting specific polarized light and reflecting or absorbing other polarized light in a certain range of wavelength bands. This refers to a wavelength band having various properties.

  In the present invention, the selective reflection layer includes at least one peak wavelength of the emission intensity peak in the selective reflection band of transmitted light in the front direction. When an example is described in relation to the spectrum of the light emitting element shown in FIG. 3, the selective reflection layer may include at least one of the wavelengths 480 nm and 575 nm in the selective reflection band of the transmitted light in the front direction. it can.

Here, the selective reflection band refers to the transmittance (λ) [%] when the maximum transmittance in the visible light range of 380 to 780 nm is a [%] and the minimum transmittance is b [%]:
{A-transmittance (λ)} / {ab} ≧ 0.3
The wavelength range that satisfies

Preferably, the selective reflection layer has a transmittance T ^F _{Y, N in} the front direction at a wavelength of 575 nm, an average value T ^F _{Y, 60} of a transmittance in the polar angle 60 ° direction at a wavelength of 575 nm, and a transmittance in the front direction at a wavelength of 480 nm. T ^F _{B, N} and the average value T ^F _{B, 60} of the transmittance in the polar angle 60 ° direction with a wavelength of 480 nm may satisfy the relationship of the formula [1]. Since the selective reflection layer has such a selective reflection band, it is possible to reduce the change in color depending on the observation angle.
_{^{(T F Y, 60 / T}} F Y, N)> (T F B, 60 / T F B, N) formula (1)

  Preferably, the selective reflection layer has one or more selective reflection bands in a wavelength range of 500 nm to 650 nm as a selective reflection band of transmitted light in the front direction. Furthermore, it is preferable that the selective reflection layer has one or more selective reflections within a wavelength range of 400 nm to 600 nm as a selective reflection band of transmitted light in a polar angle direction of 60 °, that is, a direction that forms an angle of 60 ° with the front direction. Has a band.

  FIG. 2 shows an example of the selective reflection characteristic having the selective reflection band described above in relation to the spectrum of the light emitting element shown in FIG. In FIG. 2, the selective reflection characteristic of transmitted light in an angle of 0 °, that is, in the front direction, has maximum absorption at a wavelength of 575 nm, and the selective reflection band of transmitted light in the front direction is not less than 525 nm and not more than 635 nm. As the angle of the transmitted light increases, the maximum absorption wavelength shifts to the short wavelength side, thereby satisfying the above equation [1], and further in the polar angle 60 ° direction, the maximum absorption wavelength is 490 nm, and the selective reflection band is 580 nm. It is as follows.

  In the example of the selective reflection layer having the selective reflection characteristic shown in FIG. 2, when the relationship between the incident angle of the transmitted light and the reflectance is measured, for example, the relationship shown in FIGS. 6 and 7 is obtained. FIG. 6 shows measurement results for blue light having a wavelength of 480 nm, and FIG. 7 shows measurement results for yellow light having a wavelength of 575 nm. As shown in FIG. 6, for blue light, the reflectivity increases as the incident angle increases. For yellow light, as shown in FIG. 7, the reflectivity increases as the incident angle increases due to the shift of the selective reflection band of the selective reflection layer. The characteristic that the rate increases once decreases and then appears.

  Examples of suppression of a change in color depending on the observation angle by the selective reflection layer having such selective reflection characteristics are shown in FIGS. FIG. 5 shows the organic EL light source device of the present invention shown in FIG. 1, in which the elements having the spectrum shown in FIG. 3 are used as the light emitting elements (electrode 111, electrode 112 and light emitting layer 121), and as the selective reflection layer 131, 8 is a graph showing a light distribution of blue light having a wavelength of 480 nm and yellow light having a wavelength of 575 nm emitted from the light exit surface 109 when the selective reflection layer having the selective reflection characteristics shown in FIGS. 2, 6, and 7 is used. . On the other hand, FIG. 4 is a graph showing the light distribution when the blue and yellow light distributions emitted from the substrate 101 are observed without the selective reflection layer 131 and the base film 132. As shown in these graphs, the light emitted from the substrate 101 has a difference in light distribution between blue light and yellow light, whereas the light emitted from the light exit surface 109 through the selective reflection layer 131 is: Such divergence is shrinking.

  In the organic EL light source device of the present invention, the light emitting layer 121 emits light when a voltage is applied to the transparent electrode 111 and the reflective electrode 112. Part of the generated light is directly transmitted through the transparent electrode 111, and the other part is reflected by the reflective electrode 112 and then transmitted through the transparent electrode 111. The light that has passed through the transparent electrode 111 passes through the substrate 101, the selective reflection layer 131, and the base film 132 and is emitted. Further, light reflected downward in the drawing at the interface between the light emitting layer 121 and the substrate 101 is emitted after being reflected at the reflective electrode 112 or another interface. Since there is light emitted through such various paths, light interference occurs. The increase / decrease in light due to interference differs depending on the wavelength, and as a result, the relationship between the observation angle and the luminance differs depending on the wavelength of the light, resulting in a change in color depending on the observation angle. By further transmitting such light through the selective reflection layer 131 having the specific selective reflection characteristics described above, it is possible to reduce a change in color depending on the observation angle.

  As long as the selective reflection layer used in the present invention has the above selective reflection band, any material may be used, and any selective reflection of any principle may be performed. Examples include those containing a circularly polarized light separating sheet.

  When the selective reflection layer has a circularly polarized light separating sheet, the selective reflection layer transmits only specific circularly polarized light and reflects other light (other circularly polarized light, linearly polarized light, etc.) in the selective reflection band. .

  As an example of the circularly polarized light separating sheet, a composition capable of exhibiting a cholesteric liquid crystal phase (cholesteric liquid crystal composition) is applied to a transparent resin substrate to obtain a liquid crystal layer, and then at least one light irradiation and / or addition is performed. Examples thereof include a circularly polarized light separating sheet that is cured by heat treatment.

As the cholesteric liquid crystal composition, a composition containing a rod-like liquid crystal compound that can be cured by itself or with other substances can be used. Specifically, for example, a rod-like liquid crystal compound having a Δn value of 0.10 or more and having at least two reactive groups in one molecule can be given.
More specifically, examples of the rod-like liquid crystal compound include a compound represented by the formula (1A).
^{R 3 -C 3 -D 3 -C 5} -M-C 6 -D 4 -C 4 -R 4 Formula (1A)
(Wherein R ³ and R ⁴ are reactive groups, each independently (meth) acryl group, (thio) epoxy group, oxetane group, thietanyl group, aziridinyl group, pyrrole group, vinyl group, allyl group, D ³ and D ⁴ are groups selected from the group consisting of fumarate group, cinnamoyl group, oxazoline group, mercapto group, iso (thio) cyanate group, amino group, hydroxyl group, carboxyl group, and alkoxysilyl group. A group selected from the group consisting of a bond, a linear or branched alkyl group having 1 to 20 carbon atoms, and a linear or branched alkylene oxide group having 1 to 20 carbon atoms; C ^{3 to} C ⁶ are a single bond, —O—, —S—, —S—S—, —CO—, —CS—, —OCO—, —CH ₂ —, —OCH ₂ —, —C═. N—N═C—, —NHCO— _{, -OCOO -, - CH 2 COO-} , and .M represents a group selected from the group consisting of -CH ₂ OCO- represents a mesogenic group, specifically, have a unsubstituted or substituted group Azomethines, azoxys, phenyls, biphenyls, terphenyls, naphthalenes, anthracenes, benzoic acid esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, alkoxy-substituted Two to four skeletons selected from the group of phenylpyrimidines, phenyldioxanes, tolanes, and alkenylcyclohexylbenzonitriles are converted to —O—, —S—, —S—S—, —CO—, —CS. -, - OCO -, - CH 2 -, - OCH 2 -, - C = N-N = C -, - NHCO -, - OCOO -, - C ₂ COO-, and is formed are joined by a linking group of -CH ₂ OCO-, and the like.)
Examples of the substituent that the mesogenic group M may have include a halogen atom, an optionally substituted alkyl group having 1 to 10 carbon atoms, a cyano group, a nitro group, —O—R ⁵ , —O—C. (═O) —R ⁵ , —C (═O) —O—R ⁵ , —O—C (═O) —O—R ⁵ , —NR ⁵ —C (═O) —R ⁵ , —C ( = O) -NR < ⁵ > R < ⁷ > or -O-C (= O) -NR < ⁵ > R < ⁷ >. Wherein, R ⁵ and ^{R 7} represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, when it is alkyl group, and the alkyl group, -O -, - S -, - O-C (= O) —, —C (═O) —O—, —O—C (═O) —O—, —NR ⁶ —C (═O) —, —C (═O) —NR ⁶ —, —NR ^6- or -C (= O)-may be present (except when two or more of -O- and -S- are present adjacent to each other). Wherein, R ⁶ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Examples of the substituent in the “optionally substituted alkyl group having 1 to 10 carbon atoms” include a halogen atom, a hydroxyl group, a carboxyl group, a cyano group, an amino group, and an alkoxy group having 1 to 6 carbon atoms. Group, alkoxyalkoxy group having 2 to 8 carbon atoms, alkoxyalkoxyalkoxy group having 3 to 15 carbon atoms, alkoxycarbonyl group having 2 to 7 carbon atoms, alkylcarbonyloxy having 2 to 7 carbon atoms Group, an alkoxycarbonyloxy group having 2 to 7 carbon atoms, and the like.
In the present invention, the rod-like liquid crystalline compound preferably has an asymmetric structure. Here, the asymmetric structure is a structure in which R ³ -C ³ -D ³ -C ⁵ -and -C ⁶ -D ⁴ -C ⁴ -R ⁴ are different in the general formula (1A) with the mesogenic group M as the center. Say. By using a rod-like liquid crystal compound having an asymmetric structure, alignment uniformity can be further improved.

  In the present invention, the rod-like liquid crystalline compound preferably has a Δn value of 0.10 or more. When a compound having an Δn value of 0.30 or more is used, the absorption edge on the long wavelength side of the ultraviolet absorption spectrum may extend to the visible range, but desired optical performance even when the absorption edge of the spectrum extends to the visible range. It can be used as long as it does not adversely affect By having such a high Δn value, a circularly polarized light separating sheet having high optical performance (for example, circularly polarized light separating characteristics) can be provided.

  In the present invention, the rod-like liquid crystal compound preferably has at least two reactive groups in one molecule. Specific examples of the reactive group include an epoxy group, a thioepoxy group, an oxetane group, a thietanyl group, an aziridinyl group, a pyrrole group, a fumarate group, a cinnamoyl group, an isocyanate group, an isothiocyanate group, an amino group, a hydroxyl group, and a carboxyl group. , Alkoxysilyl groups, oxazoline groups, mercapto groups, vinyl groups, allyl groups, methacryl groups, and acrylic groups. By having these reactive groups, a stable cured product can be obtained when the cholesteric liquid crystal composition is cured.

In the present invention, the cholesteric liquid crystal composition can optionally contain a crosslinking agent in order to improve the film strength and durability after curing. As the cross-linking agent, it reacts simultaneously when the liquid crystal layer coated with the liquid crystal composition is cured, or heat treatment is performed after curing to accelerate the reaction, or the reaction proceeds spontaneously by moisture to increase the cross-linking density of the liquid crystal layer. Those that can be enhanced and that do not deteriorate the alignment uniformity can be appropriately selected and used, and those that are cured by ultraviolet rays, heat, moisture, etc. can be suitably used. Specific examples of the crosslinking agent include, for example, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 2- (2-vinyl Polyfunctional acrylate compounds such as loxyethoxy) ethyl acrylate; epoxy compounds such as glycidyl (meth) acrylate, ethylene glycol diglycidyl ether, glycerin triglycidyl ether, pentaerythritol tetraglycidyl ether; 2,2-bishydroxymethylbutanol-tris [ 3- (1-aziridinyl) propionate], 4,4-bis (ethyleneiminocarbonylamino) diphenylmethane, trimethylolpropane-tri-β-aziridinini Aziridine compounds such as lupropionate; Isocyanurate type isocyanates derived from hexamethylene diisocyanate, hexamethylene diisocyanate, isocyanurate type isocyanates, biuret type isocyanates, adduct type isocyanates; polyoxazoline compounds having an oxazoline group in the side chain; vinyltrimethoxysilane; N- (2-aminoethyl) 3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane, N- (1 , 3-dimethylbutylidene) -3- (triethoxysilyl) -1-propanamine and the like alkoxysilane compounds. Moreover, a well-known catalyst can be used according to the reactivity of this crosslinking agent, and productivity can be improved in addition to an improvement in film strength and durability.
The blending ratio of the crosslinking agent is preferably 0.1 to 15% by weight in a cured film obtained by curing the cholesteric liquid crystal composition. When the blending ratio of the crosslinking agent is less than 0.1% by weight, the effect of improving the crosslinking density cannot be obtained. Conversely, when the blending ratio is more than 15% by weight, the stability of the liquid crystal layer is lowered, which is not preferable.

In the present invention, the cholesteric liquid crystal composition can optionally contain a photoinitiator. As the photoinitiator, known compounds that generate radicals or acids by ultraviolet rays or visible rays can be used. Specifically, benzoin, benzylmethyl ketal, benzophenone, biacetyl, acetophenone, Michler's ketone, benzyl, benzylisobutyl ether, tetramethylthiuram mono (di) sulfide, 2,2-azobisisobutyronitrile, 2,2-azobis -2,4-dimethylvaleronitrile, benzoyl peroxide, di-tert-butyl peroxide, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1- (4 -Isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-diethylthioxanthone, methylbenzoyl formate, 2,2-dieto Cyacetophenone, β-ionone, β-bromostyrene, diazoaminobenzene, α-amylcinnac aldehyde, p-dimethylaminoacetophenone, p-dimethylaminopropiophenone, 2-chlorobenzophenone, pp′-dichlorobenzophenone, pp ′ -Bisdiethylaminobenzophenone, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-propyl ether, benzoin n-butyl ether, diphenyl sulfide, bis (2,6-methoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, 2,4,6-trimethylbenzoyldiphenyl-phosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2-methyl-1 [ 4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, anthracenebenzophenone, α-chloroanthraquinone , Diphenyl disulfide, hexachlorobutadiene, pentachlorobutadiene, octachlorobutene, 1-chloromethylnaphthalene, 1,2-octanedione, 1- [4- (phenylthio) -2- (o-benzoyloxime)] and 1- [9-Ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] ethanone 1- (o-acetyloxime), (4-methylphenyl) [4- (2-methylpropyl) phenyl] iodonium Hexafluorophosphate, 3-methyl-2-butynyltetramethylsulfonate Arm hexafluoroantimonate, diphenyl - (p-phenylthiophenyl) sulfonium hexafluoroantimonate, and the like. In addition, two or more compounds can be mixed depending on the desired physical properties, and if necessary, a known photosensitizer or a tertiary amine compound as a polymerization accelerator is added to control curability. You can also.
The blending ratio of the photoinitiator is preferably 0.03 to 7% by weight in the cholesteric liquid crystal composition. When the blending amount of the photoinitiator is less than 0.03% by weight, the degree of polymerization is lowered and the film strength may be lowered. On the other hand, if it is more than 7% by weight, the alignment of the liquid crystal is inhibited and the liquid crystal phase may become unstable.

  In the present invention, the cholesteric liquid crystal composition can optionally contain a surfactant. As the surfactant, those not inhibiting the orientation can be appropriately selected and used. As the surfactant, specifically, a nonionic surfactant containing siloxane or fluorinated alkyl group in the hydrophobic group portion can be preferably used, and an oligomer having two or more hydrophobic group portions in one molecule. Is particularly preferred. These surfactants are PF-151N, PF-636, PF-6320, PF-656, PF-6520, PF-3320, PF-651, PF-652 from PolyFox, OMNOVA, FTX- from Neos 209F, FTX-208G, FTX-204D, Seimi Chemical's Surflon KH-40, and the like can be used. The blending ratio of the surfactant is preferably 0.05% by weight to 3% by weight in the cured film obtained by curing the cholesteric liquid crystal composition. When the blending ratio of the surfactant is less than 0.05% by weight, the orientation regulating force at the air interface is lowered and an orientation defect may occur, which is not preferable. On the other hand, when the amount is more than 3% by weight, it is not preferable because an excessive surfactant may enter between liquid crystal molecules and lower the alignment uniformity.

  In the present invention, the cholesteric liquid crystal composition can further contain other optional components as necessary. Examples of the other optional components include a chiral agent, a solvent, a polymerization inhibitor for improving pot life, an antioxidant for improving durability, an ultraviolet absorber, and a light stabilizer. These optional components can be added as long as the desired optical performance is not deteriorated.

  The manufacturing method of a cholesteric liquid crystal composition is not specifically limited, It can manufacture by mixing the said essential component and arbitrary components.

  In the present invention, as a method of forming the selective reflection layer using the cholesteric liquid crystal composition, the cholesteric liquid crystal composition is applied to the base film 132 to obtain a liquid crystal layer, and then at least one time of light irradiation and And / or a method of curing by heating treatment.

  The material of the substrate film 132 is not particularly limited, and a substrate having a thickness of 1 mm and a total light transmittance of 80% or more can be used. Specifically, alicyclic olefin polymers, chain olefin polymers such as polyethylene and polypropylene, triacetyl cellulose, polyvinyl alcohol, polyimide, polyarylate, polyester, polycarbonate, polysulfone, polyethersulfone, modified acrylic polymer, epoxy resin, Examples thereof include a single layer or laminated film made of a synthetic resin such as polystyrene or acrylic resin. Among these, an alicyclic olefin polymer or a chain olefin polymer is preferable, and an alicyclic olefin polymer is particularly preferable from the viewpoint of transparency, low hygroscopicity, dimensional stability, lightness, and the like.

  The said base film can have an orientation film as needed. By having the alignment film, the cholesteric liquid crystal composition applied thereon can be aligned in a desired direction. The alignment film is subjected to corona discharge treatment, if necessary, on the substrate surface, followed by cellulose, silane coupling agent, polyimide, polyamide, polyvinyl alcohol, epoxy acrylate, silanol oligomer, polyacrylonitrile, phenol resin, poly A solution in which oxazole, cyclized polyisoprene or the like is dissolved in water or a solvent is applied using a known method such as reverse gravure coating, direct gravure coating, die coating, bar coating, and the like, and then dried. It can be formed by subjecting to rubbing treatment. The thickness of the alignment film may be any film thickness that provides the desired alignment uniformity of the liquid crystal layer, and is preferably 0.001 to 5 μm, and more preferably 0.01 to 2 μm.

  Application | coating of the liquid-crystal composition to the said base film can be performed by well-known methods, such as reverse gravure coating, direct gravure coating, die coating, and bar coating. The thickness of the coating layer of the liquid crystal composition can be appropriately adjusted so that a desired liquid crystal layer dry film thickness described later can be obtained.

  Before curing the coating layer obtained by the coating, an orientation treatment can be performed as necessary. The alignment treatment can be performed, for example, by heating the coating layer at 50 to 150 ° C. for 0.5 to 10 minutes. By performing the alignment treatment, the cholesteric liquid crystal layer can be aligned well.

A cured liquid crystal layer that is a cured product of the cholesteric liquid crystal composition can be obtained by curing the cholesteric liquid crystal composition after performing an alignment treatment as necessary. The curing step can be performed by a combination of one or more light irradiations and a heating treatment. Specifically, the heating conditions are, for example, a temperature of 40 to 200 ° C., preferably 50 to 200 ° C., more preferably 50 to 140 ° C., and a time of 1 second to 3 minutes, preferably 5 to 120 seconds. it can. The light used for light irradiation in the present invention includes not only visible light but also ultraviolet rays and other electromagnetic waves. Specifically, the light irradiation can be performed by, for example, irradiating light having a wavelength of 200 to 500 nm for 0.01 second to 3 minutes. Further, for example, a weakly irradiated ultraviolet ray of 0.01 to 50 mJ / cm ² and heating may be alternately repeated several times to obtain a circularly polarized light separating sheet having a wide reflection band. After extending the reflection band by the above-mentioned weak ultraviolet irradiation, etc., a relatively strong ultraviolet ray of 50 to 10,000 mJ / cm ² is irradiated to completely polymerize the liquid crystalline compound to form a cured liquid crystal layer. it can. The expansion of the reflection band and the irradiation with strong ultraviolet rays may be performed in the air, or a part or all of the process may be performed in an atmosphere in which the oxygen concentration is controlled (for example, in a nitrogen atmosphere). .

  In the present invention, the step of applying and curing the cholesteric liquid crystal composition on the transparent resin substrate is not limited to one time, and two or more cured liquid crystal layers can be formed by repeating the application and curing a plurality of times.

  In the selective reflection layer, a dry film thickness of the cured liquid crystal layer is preferably 0.5 μm to 10.0 μm, more preferably 1.0 μm to 5.0 μm. If the dried film thickness of the cured liquid crystal layer is thinner than 0.5 μm, the reflectivity decreases, and conversely if it is thicker than 10.0 μm, the cured liquid crystal layer is colored when observed from an oblique direction, Each is not preferred. The dry film thickness refers to the total film thickness of each layer when the cured liquid crystal layer is two or more layers, and the film thickness when the cured liquid crystal layer is one layer.

  By the above process, a laminated structure having the base film 132 and the selective reflection layer 131 provided thereon is obtained. By sticking this on the substrate 101, the structure of the substrate 101, the selective reflection layer 131 and the base film 132 shown in FIG. 1 can be obtained. Preferably, the light-emitting element 120 including the transparent electrode 111, the light-emitting layer 121, the reflective electrode 112, and the like is provided on one surface of the substrate 101, and then the base film 132 and the selective reflection layer 131 are provided on the opposite surface of the substrate 101. The body can be affixed.

(Second Embodiment)
FIG. 8 is a cross-sectional view showing the layer configuration of the second embodiment of the organic EL light source device of the present invention. In FIG. 8, an apparatus 800 is different from the first embodiment in that a diffusion layer 841 is provided between the substrate 101 and the selective reflection layer 131.

Such a diffusion layer 841 includes:
Diffusion layer (b): a resin in which particles as fillers are dispersed in a resin as a binder, and diffusion layer (b): a film having fine irregularities can be used.

(Diffusion layer (I))
In the case of using the diffusion layer (a) (a diffusion layer composed of a binder and a filler) as the diffusion layer, the binder resin includes an epoxy resin, a silicone resin, an acrylic resin, polyethylene, a propylene-ethylene copolymer, polystyrene, Copolymer of aromatic vinyl monomer and (meth) acrylic acid alkyl ester having lower alkyl group, polyethylene terephthalate, terephthalic acid-ethylene glycol-cyclohexanedimethanol copolymer, polycarbonate, alicyclic structure Resin or the like can be used.

The filler material is not particularly limited, and inorganic and organic fillers can be appropriately selected and used.
Inorganic fillers include glass, silicon oxide, aluminum hydroxide, aluminum oxide, titanium oxide, zinc oxide, barium sulfate, magnesium silicate, etc .; organic fillers include fluororesin, polystyrene resin, acrylic resin, polycarbonate resin, Examples thereof include silicone resin, polyethylene resin, ethylene-vinyl acetate copolymer, acrylonitrile, polyurethane, polyvinyl chloride, polyacrylonitrile, polyamide, polysiloxane resin, melamine resin, benzoguanamine resin, or a cross-linked product thereof.

  The shape of the filler is not particularly limited, and examples thereof include a spherical shape, an ellipsoidal shape, a cubic shape, a needle shape, a rod shape, a spindle shape, a plate shape, a scale shape, and a fiber shape. Spherical or nearly ellipsoidal shape is preferable in that it can be achieved.

  The size of the filler is preferably 0.2 μm to 50 μm in diameter, more preferably 0.5 μm to 10 μm. In addition, when the diameter here is not a perfect sphere, the diameter of the sphere of the same volume is substituted. In the case of a filler having a significantly different size in one direction such as a needle shape, a diameter of a circle having the same area as the cross-sectional area of the cross section perpendicular to the direction is substituted.

  The refractive index of the filler is preferably different from the refractive index of the binder resin, and the refractive index difference is more preferably 0.05 or more.

  The filler may be a single material, size, refractive index or other properties, or a mixture of two or more fillers. Moreover, you may use what consists of 2 or more types of raw materials as a filler.

  The content of the filler in the diffusion layer composed of the binder and the filler is preferably 0.1 to 20 parts by weight, more preferably 1 to 10 parts by weight with respect to 100 parts by weight of the binder.

  The ratio between the average particle diameter d of the filler contained in the diffusion layer (a) and the thickness l of the diffusion layer is preferably 0.05 ≦ d / l ≦ 0.6, particularly preferably 0.07 ≦ d / l. ≦ 0.3. If it is less than 0.05, the particle size of the filler is too small or the layer thickness is too thick, so that the required scattering characteristics may not be obtained if the former, but the latter does not require a diffusion layer. If it exceeds 0.6, the adhesive force between the diffusion layer and other layers may be insufficient, and the diffusion layer may peel off. The thickness of the diffusion layer (A) can be 0.02 to 3.0 mm.

(Diffusion layer (b))
On the other hand, in the case where the diffusion layer (b) (a film having fine irregularities) is used as the diffusion layer, the film is a step of obtaining a laminate by forming a thin film on one surface of the diffusion layer film substrate. And a step of shrinking the laminated body in at least one axial direction to bend the thin film.

(Diffusion layer (b): Diffusion layer film substrate)
The diffusion layer film substrate used for the production of the diffusion layer is not particularly limited as long as it can be contracted in at least one axial direction in the plane after the thin films are laminated. For example, the diffusion layer film substrate itself may be shrunk by a means such as heating, or may be shrunk in a direction orthogonal to the stretching direction when uniaxially stretched.

  The average thickness before shrinkage of the diffusion layer film substrate is usually 5 to 1000 μm, preferably 20 to 200 μm from the viewpoint of handling.

  The diffusion layer film substrate is usually made of resin, rubber or elastomer. As the resin, styrene resin, acrylic resin, methacrylic resin, organic acid vinyl ester resin, vinyl ether resin, halogen-containing resin, olefin resin, resin having alicyclic structure, polycarbonate resin, polyester resin, polyamide resin, thermoplastic polyurethane resin , Polysulfone resins (eg, polyethersulfone, polysulfone, etc.), polyphenylene ether resins (eg, polymers of 2,6-xylenol), cellulose derivatives (eg, cellulose esters, cellulose carbameters, cellulose ethers, etc.) And silicone resins (for example, polydimethylsiloxane, polymethylphenylsiloxane, etc.).

  Examples of the resin having an alicyclic structure include the same ones as described above. For example, a cyclic olefin random described in JP-A No. 05-310845 and US Pat. No. 5,179,171. Copolymers, hydrogenated polymers described in JP-A-05-97978 and US Pat. No. 5,202,388, thermoplastic dithers described in JP-A-11-124429 and WO99 / 20676 And cyclopentadiene ring-opening polymers and hydrogenated products thereof.

  Examples of rubber or elastomer include diene rubber such as polybutadiene and polyisoprene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, acrylic rubber, urethane rubber, and silicone rubber. Among these, the material of the diffusion layer film base material is preferably a thermoplastic resin from the viewpoint of easy production.

  The thermoplastic resin constituting the diffusion layer film substrate is not particularly limited, but preferably has a glass transition temperature of 60 to 200 ° C, more preferably 100 to 180 ° C from the viewpoint of ease of processing. The glass transition temperature can be measured by differential scanning calorimetry (DSC).

  The thermoplastic resin constituting the diffusion layer film substrate preferably has a polystyrene equivalent weight average molecular weight of 5,000 to 500,000, more preferably 8,000 to 200,000, and particularly preferably 10,000. ~ 100,000. When the weight average molecular weight is within this range, molding processability is improved and mechanical strength can be improved. This weight average molecular weight can be measured by gel permeation chromatography.

  Resin, rubber or elastomer constituting the diffusion layer film base is a colorant such as pigment or dye, fluorescent whitening agent, dispersant, thermal stabilizer, light stabilizer, ultraviolet absorber, antistatic agent, antioxidant Agent, chlorine scavenger, flame retardant, crystallization nucleating agent, antiblocking agent, antifogging agent, mold release agent, organic or inorganic filler, neutralizing agent, lubricant, decomposition agent, metal deactivator, contamination prevention Agents, antibacterial agents, diffusing particles, thermoplastic elastomers and other compounding agents may be appropriately blended.

  The diffusion layer film substrate is not particularly limited by the production method. The raw material of the diffusion layer film substrate can be obtained by forming the above-described resin or the like by a known film forming method. Examples of the diffusion layer film forming method include a cast forming method, an extrusion forming method, and an inflation forming method.

  In general, the diffusion layer film base material that shrinks itself by means of heating or the like is preferably molecularly oriented in the plane. Originally, a molecule tends to be in a low energy arrangement state corresponding to an interatomic bond angle. The state in which molecules are regularly arranged in a plane includes distortion in the bonding state of the molecules, and can be said to be a high energy arrangement state. When the diffusion layer film base material in the high energy arrangement state is heated, the molecules try to return to the low energy arrangement state, and the entire diffusion layer film base material contracts. The state of molecular orientation can be measured by a known method, for example, using an automatic birefringence meter KOBRA21ADH.

  The diffusion layer film base material that itself shrinks by means of heating or the like can be obtained, for example, by forming the above-described resin or the like on a raw film by a known molding method and stretching the raw film. Moreover, it can be set as the film base material which orients a molecule | numerator by applying a magnetic field, an electric field, or a rubbing process instead of an extending | stretching process, and shows a contractility. By forming rubber or elastomer on an elastic film by a known molding method and pulling the elastic film in the in-plane direction, it is possible to obtain a film base material that exhibits shrinkage utilizing resilience due to elasticity. . Furthermore, a film made of a curable resin can be swollen with a solvent or the like in advance, and a film substrate can be formed by utilizing the shrinkage that occurs when the swollen film dries. Among these, the film base material which shows the contractility obtained by extending | stretching a raw film is preferable.

  The diffusion layer film base material exhibiting shrinkage obtained by stretching the raw film is not particularly limited by the stretching method, and may be stretched by either a uniaxial stretching method or a biaxial stretching method. In the case of biaxial stretching, it usually shrinks in two directions within the film plane. Stretching methods include a method of uniaxial stretching in the longitudinal direction using the difference in peripheral speed on the roll side; a uniaxial stretching method such as a method of uniaxial stretching in the transverse direction using a tenter stretching machine; At the same time as stretching in the longitudinal direction using the guide rail, the biaxial stretching method that stretches in the transverse direction depending on the spread angle of the guide rail, and the longitudinal direction using the difference in the peripheral speed between the rolls, and both ends thereof And a biaxial stretching method such as a sequential biaxial stretching method in which the film is gripped and stretched in the transverse direction using a tenter stretching machine.

  When the shrinkage rate in the main shrinkage direction is significantly increased, elongation may occur in a direction perpendicular to the main shrinkage direction, and the elongation may cause cracks in the uneven shape. From the viewpoint of suppressing the occurrence of cracks during shrinkage, (i) uniaxially stretching in the transverse direction is preferably performed with the longitudinal shrinkage during stretching preferably controlled to 20% or less, more preferably 15% or less (transverse) Uniaxial stretching method) or (II) biaxial stretching in the longitudinal and lateral directions (biaxial stretching method) is preferred.

  Examples of the apparatus used for stretching include a longitudinal uniaxial stretching machine, a tenter stretching machine, a bubble stretching machine, and a roller stretching machine.

  The temperature during stretching is preferably between (Tg-30 ° C) and (Tg + 60 ° C), more preferably (Tg-10 ° C), where Tg is the glass transition temperature of the material constituting the diffusion layer film substrate. ) And (Tg + 50 ° C.). What is necessary is just to select a draw ratio suitably so that it may become the dimension of the unevenness | corrugation desired according to the tension | pulling characteristic of the film to be used.

  When it is desired to obtain high irregularities, the stretch ratio is generally set high although it depends on the film quality and thickness of the thin film. In order to obtain low unevenness, the draw ratio is set low. For example, the draw ratio in the main drawing direction is usually 1.01 to 30 times, preferably 1.01 to 10 times, and more preferably 1.05 to 5 times. When the draw ratio is less than 1.01, the concavo-convex shape may not occur, and when it is more than 30 times, the film strength may be reduced. For this reason, a draw ratio can be made into the said suitable range.

(Diffusion layer (b): Thin film)
The average thickness of the thin film before shrinkage is preferably 1 nm to 50 μm. As for the thickness of the thin film, a vertical section of the thin film is photographed with a transmission electron microscope, and an average value of the thickness is obtained from the photograph image.

  Thin films include inorganic thin films and organic thin films. The inorganic thin film used in the present invention is made of an inorganic substance. Examples of the inorganic substance constituting the thin film include metals; metal compounds such as metal oxides and metal nitrides; nonmetals; nonmetal compounds such as nonmetal oxides. Specifically, aluminum, silicon, magnesium Metal, nonmetal such as palladium, platinum, zinc, tin, nickel, silver, copper, gold, antimony, yttrium, indium, stainless steel, chromium, titanium, tantalum, zirconium, niobium, lanthanum, cerium; or their oxidation And nitrides; or mixtures thereof.

  The average thickness of the inorganic thin film is preferably 1 nm to 5 μm. If the thickness is less than 1 nm, it is difficult to form a concavo-convex shape. If the thickness is more than 5 μm, cracks are likely to occur in the inorganic thin film layer during shrinkage. When an inorganic thin film is used, a fine concavo-convex shape having an average distance between the convex vertices of 50 nm to 10 μm can be easily obtained.

  The method for forming the inorganic thin film is not particularly limited, and vapor deposition methods such as vacuum deposition, ion plating, sputtering, CVD (chemical vapor deposition); spin coating method, dating method, roll coating method, spray method, vapor method, gravure Examples thereof include coating methods such as a coater and a blade coater, coating methods such as a screen printing method and an ink jet method; an electroless plating method and an electrolytic plating method.

  The organic thin film is not particularly limited as long as the thin film has a curved structure due to shrinkage. The organic thin film preferably has a shrinkage rate under a temperature condition for shrinking the diffusion layer film substrate smaller than that of the diffusion layer film substrate. The average thickness of the organic thin film is preferably 100 nm to 50 μm. If the thickness is less than 100 nm, it is difficult to form the uneven shape, and if it is more than 50 μm, it is difficult to control the unevenness, which is not preferable. When an organic thin film is used, a fine concavo-convex shape having an average distance between vertices of convex portions of 500 nm to 50 μm can be easily obtained.

  Examples of the organic thin film include those made of a thermoplastic resin and those made of a curable resin.

  As a thermoplastic resin, the thing similar to what was illustrated as what can be used for the said diffusion layer film base material can be mentioned. Moreover, the thin film may contain the compounding agent like resin used for the said diffusion layer film base material.

  As a method for forming an organic thin film made of a thermoplastic resin, (1) a method of co-extruding a resin constituting a diffusion layer film substrate and a resin constituting a thin film; (2) molding a thermoplastic resin into a thin film (3) A method of applying a solution containing thermoplastic resin on the surface of the diffusion layer film substrate and drying it.

  The curable resin includes a thermosetting resin and an energy beam curable resin. The energy rays refer to visible light, ultraviolet rays, electron beams, and the like.

  Specific examples of the thermosetting resin include phenol resin, urea resin, diallyl phthalate resin, melamine resin, guanamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin, aminoalkyd resin, melamine urea co-condensation resin, silicon resin, Examples thereof include polysiloxane resins.

  The energy ray curable resin is not particularly limited. For example, the radical polymerizable unsaturated group (for example, acryloyloxy group, methacryloyloxy group, vinyloxy group, styryl group, vinyl group, etc.) and / or cationic polymerizable group (epoxy) Group, thioepoxy group, vinyloxy group, oxetanyl group, etc.), specifically, relatively low molecular weight polyester resin, polyether resin, acrylic resin, methacrylic resin, epoxy resin, urethane resin, alkyd Examples thereof include resins, spiroacetal resins, polyptagene resins, polythiol polyene resins, and the like.

  When ultraviolet rays or visible rays are used as energy rays, a photopolymerization initiator, a photosensitizer, or the like is included in the curable resin. Examples of the photopolymerization initiator include acetophenones, benzophenones, Michler benzoylbenzoate, α-amyloxime ester, tetramethylthiuram monosulfide, thioxanthones, and the like. Examples of the photosensitizer include n-butylamine, triethylamine, and tri-n-butylphosphine.

  The thin film made of a curable resin may contain compounding agents such as a curing agent such as a crosslinking agent and a polymerization initiator, a polymerization accelerator, a solvent, and a viscosity modifier.

  The formation method of the organic thin film which consists of curable resin is not specifically limited. The organic thin film which consists of curable resin is obtained by apply | coating the composition of curable resin to the diffusion layer film base-material surface, and hardening, for example. When forming the curable resin thin film, it is desirable to heat-treat at a temperature lower by 5 ° C. or more than the glass transition temperature T1 of the diffusion layer film substrate. If a high temperature is applied during the formation of the thin film, the diffusion layer film substrate is annealed and may not shrink as designed. As the organic thin film, it is preferable to use a curable resin thin film because the fine uneven shape may be easily controlled.

(Diffusion layer (b): fold-induced structure)
In this production method, before forming a thin film on the surface of the diffusion layer film substrate, a structure for causing the bending of the thin film (folding induction structure) is formed on the surface of the diffusion layer film substrate, or the diffusion layer Forming a structure (curvature inducing structure) for causing bending of the thin film on the thin film after forming the thin film on the surface of the film base and before shrinking the base; This is preferable in the case where it is desired to improve the uniformity of the distance between the apexes of the convex portion (strip or ridge). The structure is not particularly limited as long as it causes a bending of the thin film when the base material contracts. For example, the structure is scratched on the surface by rubbing or other methods, and is mounted by an inkjet printer or a printing machine. Examples include irregularities provided by ink stamping, embossing, imprinting, and the like. It is preferable that the bending induction structure is formed at a constant interval. The interval between the fold-inducing structures is not directly related to the distance between the desired convex and concave convex vertices, and may be narrower or wider than the desired convex and concave convex distance. It is preferable that the distance between the bending induction structures is 0.05 to 100 times the desired distance between the convex vertices of the shape.

  Next, the diffusion layer film base material on which the thin film is formed is contracted to bend the thin film. The method for shrinking the diffusion layer film substrate may be appropriately selected according to the type of the diffusion layer film substrate.

The shrinkage rate of the diffusion layer film base is such that when the thin film is bent due to shrinkage of the diffusion layer film base, the shrinkage ΔL in the main shrinkage direction and the main shrinkage direction in order to prevent the thin film and the like from being cracked. It is preferable that the contraction rate ΔM in the direction orthogonal to the equation [7] and [8].
ΔL and ΔM are defined by equations [5] and [6], respectively.

Formula [5]: ΔL = (L0−L1) / L0 × 100 (L0: length before contraction in the main contraction direction, L1: length after contraction in the main contraction direction)
Formula [6]: ΔM = (M0−M1) / M0 × 100 (M0: length before contraction in the direction orthogonal to the main contraction direction, M1: length after contraction in the direction orthogonal to the main contraction direction)
Formula [7]: ΔL> 0
Formula [8]: − (ΔL × 0.3) ≦ ΔM ≦ ΔL
When it is desired to increase the anisotropy of the fine concavo-convex shape, that is, when it is desired to make the concavo-convex shape elongated in stripes in the plane, it is preferable to satisfy the equations [7] and [9].

Formula [9]: − (ΔL × 0.2) ≦ ΔM ≦ (ΔL × 0.2)
As described above, the distance between the convex vertices, the height of the irregularities, and the like can be arbitrarily adjusted simply by changing the shrinkage conditions, which is suitable for manufacturing a diffusion layer having a row.

  The main shrinkage direction is the direction in which the degree of shrinkage (shrinkage rate) is the largest. For example, a diffusion layer film substrate obtained by stretching a film made of a thermoplastic resin shrinks by heating. When the film is stretched only in a uniaxial direction, the stretching direction is usually the main shrinking direction. Moreover, when extending | stretching to a biaxial direction, a direction with a large extending | stretching ratio becomes a main shrinking direction among two extended directions normally.

  When a film made of a thermoplastic resin is uniaxially stretched, the film shrinks in a direction perpendicular to the stretching direction during stretching. In the diffusion layer film substrate using the shrinkage at the time of stretching, the direction perpendicular to the stretching direction is the main shrinking direction. In addition, when the value of the shrinkage rate ΔM in the direction orthogonal to the main shrinkage direction is negative, it indicates that the film has been stretched in the shrinkage treatment. When the film shrinks in the main shrinking direction, if the elongation in the direction perpendicular to the main shrinking direction becomes too large, the thin film tends to crack.

  The shrinkage rate in the direction orthogonal to the main shrinkage direction is preferably 1% to 90%, and more preferably 1% to 50%.

  The height of the unevenness of the diffusion layer (b) is preferably 0.3 μm or more because good diffusion and color correction effects can be obtained.

(3rd Embodiment and 4th Embodiment)
10 and 11 are cross-sectional views showing the layer structure of an organic EL light source device 1100 that is the third embodiment of the organic EL light source device of the present invention and an organic EL light source device 1200 that is the fourth embodiment.
In the light source device 800 of the second embodiment described above, the diffusion layer 841 is provided between the substrate 101 and the selective reflection layer 131. However, as in the third embodiment, the diffusion layer 1141 is used as the light output of the light source device. It can also be configured to lie on the surface 109. In such an apparatus, for example, an alignment film (not shown) is provided on the substrate 101 as necessary, and then the cholesteric liquid crystal composition as a material of the selective reflection layer and the binder as a material of the diffusion layer and It can be produced by sequentially applying and curing the filler composition.
Further, as in the fourth embodiment, a laminate in which the diffusion layer 1241 and the selective reflection layer 131 are provided on the base film 1252 is pasted via the adhesive layer 1251, so that these are provided on the surface of the apparatus. The organic EL light source device 1200 can also be used.

(Fifth embodiment)
8, the layer configuration of the organic EL light source device according to the fifth embodiment of the present invention includes a concavo-convex structure 1361 between the substrate 101 and the selective reflection layer 131 instead of the diffusion layer 841. This point is different from the second embodiment shown in FIG.

  Here, the structure 1361 may have any shape as long as two or more surfaces having an inclination angle are formed on the surface, and examples thereof include a wave shape, a prism shape, a rectangular shape, and a conical shape. Further, they may be regularly arranged or randomly arranged.

  Although the use of the organic EL light source device of the present invention is not particularly limited, it can be used as a light source for a backlight of a liquid crystal display device, an illumination device, and the like, taking advantage of less tint depending on the viewing angle.

Hereinafter, the present invention will be described in more detail based on examples. In addition, this invention is not limited to the following Example.
<Production Example 1: Preparation of circularly polarized light separating sheet>
(P1-1: Preparation of transparent resin base film)
Both surfaces of a film made of an alicyclic olefin polymer (trade name “ZEONOR FILM ZF14-100” manufactured by Optes Co., Ltd.) were subjected to corona discharge treatment. An aqueous solution of 5% polyvinyl alcohol was applied to one side of the film using a # 2 wire bar, and the coating film was dried to form an alignment film having a thickness of 0.1 μm. Next, the alignment film was rubbed to prepare a transparent resin substrate film having the alignment film.

(P1-2: Formation of cured liquid crystal layer)
A cholesteric liquid crystal composition for constituting a cured liquid crystal layer was prepared with the following composition.
Solid content 40% by weight
Liquid crystalline compound (Δn (ne-no) = 0.13 rod-like liquid crystal compound 95.70 parts by weight Photopolymerization initiator (trade name IRG907 manufactured by Ciba Specialty Chemicals) 3.1 parts by weight Surfactant (Seimi Chemical Co., Ltd., trade name KH-40) 0.11 parts by weight Chiral agent (BASF, trade name LC756) 4.30 parts by weight Solvent Methyl ethyl ketone 154.82 parts by weight

This cholesteric liquid crystal composition was applied to the surface having the alignment film of the transparent resin substrate film having the alignment film prepared in (P1-1) using a # 4 wire bar. The coating film was dried at 100 ° C. for 5 minutes and subjected to orientation aging. The coating film was further irradiated with ultraviolet rays of 1.0 mJ / cm ² (UV-A: 365 nm ± 5 nm), held at 100 ° C. for 1 minute, and then irradiated with ultraviolet rays of 500 mJ / cm ² to cure the coating film, A circularly polarized light separating sheet in which a selective reflection layer 131 having a dry film thickness of 2 μm was provided on a base film 132 through an alignment film was produced. When the reflection spectrum of the obtained circularly polarized light separating sheet was measured using a spectrophotometer (JASCO V-550 manufactured by JASCO Corporation), it had selective reflection measurement as shown in FIG. 2, FIG. 6 and FIG. It was.

<Example 1>
An organic EL light source device having the configuration of the first embodiment of the present invention shown in FIG. 1 was manufactured.

(1-1: Preparation of light-emitting element)
On one surface of a glass substrate 101 having a thickness of 1.1 mm, an organic EL light emitting element including the transparent electrode 111, the organic light emitting layer 121, and the reflective electrode 112 was provided.

  At this stage, a current was applied to the organic EL light emitting device, and the light distribution of blue light having a wavelength of 480 nm and yellow light having a wavelength of 575 nm emitted from the substrate 101 was measured. The result shown in FIG. 4 was obtained.

(1-2: Manufacture of organic EL light source device)
Further, the circularly polarized light separating sheet obtained in Production Example 1 is pasted on the other surface of the substrate 101 so that the selective reflection layer 131 faces the substrate 101, and the organic EL light source device having the configuration shown in FIG. 1 is manufactured. did. When a current was passed through the obtained organic EL light emitting device and the light distribution of blue light having a wavelength of 480 nm and yellow light having a wavelength of 575 nm emitted from the light exit surface 109 was measured, the results shown in FIG. 5 were obtained.

  4 and 5, the organic EL light source device of the present invention including the circularly polarized light separating sheet in addition to the light emitting element is more blue light than the light emitting element not provided with the circularly polarized light separating sheet. It can be seen that there is a small difference in light distribution between yellow light and yellow light, and there is little change in color depending on the viewing angle.

<Example 2>
An organic EL light source device having the configuration of the second embodiment of the present invention shown in FIG. 8 was manufactured.

(2-1: Production of resin base material in which diffusing agent is dispersed)
97 parts by weight of a resin having an alicyclic structure in a transparent resin (Nippon ZEON Co., Ltd., ZEONOR) and fine particles comprising a cross-linked product of a polysiloxane polymer as a light diffusing agent (GE Toshiba Silicone Co., Ltd., Tospearl 120) 3 parts by weight was mixed, kneaded with a twin screw extruder, extruded into a stride shape, and cut with a pelletizer to produce a light diffusion substrate pellet. From this pellet, a substrate having a thickness of 0.7 mm and smooth on both sides was molded using an injection molding machine.

(2-2: Manufacture of organic EL light source device)
The circularly polarized light separating sheet obtained in (Production Example 1) and the resin base material obtained in (2-1) above are stuck so as to be in the order of selective reflection layer 131 / diffusion layer 841 / substrate 101, and a laminate. Was prepared. The laminated body and the organic EL light-emitting element having the layer structure of the glass substrate 101 / transparent electrode 111 / organic light-emitting layer 121 / reflective electrode 112 obtained in the step (1-1) of Example 1, An organic EL light source device having the configuration shown in FIG. 8 was manufactured. When current was passed through the obtained organic EL light emitting device and the light distribution was measured for blue light having a wavelength of 480 nm and yellow light having a wavelength of 575 nm emitted from the light exit surface 109, the results shown in FIG. 9 were obtained.

  As is clear from the comparison of the results of FIGS. 4 and 9, the organic EL light source device of the present invention having a diffusion layer in addition to the light emitting element and the circularly polarized light separating sheet is compared with the light emitting element not provided with the circularly polarized light separating sheet. Thus, it can be seen that the difference in light distribution between the blue light and the yellow light is small, and the change in color depending on the observation angle is small. Further, as is clear from the comparison between FIG. 5 and FIG. 9, by providing the diffusion layer, the difference in the light distribution between the blue light and the yellow light is further smaller than that of the organic EL light source device of Example 1 that does not include the diffusion layer. It has become.

<Example 3>
(3-1: Preparation of transparent resin base film)
Pellets of alicyclic olefin resin (manufactured by Nippon Zeon Co., Ltd., ZEONOR 1420, glass transition temperature 136 ° C.) were dried at 100 ° C. for 4 hours using a hot air dryer in which nitrogen was circulated. Next, this pellet was extruded at a molten resin temperature of 260 ° C. using a T-die film melt extrusion molding machine equipped with a 50 mmφ screw to produce a film having a width of 650 mm and a thickness of 188 μm. Each was trimmed to obtain a raw film made of an alicyclic olefin resin having a width of 600 mm.

  Both ends of a 600 mm wide raw film are held by clips and introduced into a tenter stretching machine. At a temperature of 140 ° C., the film is uniaxial so that the stretching ratio is 1.3 times in the film width direction and 1 time in the film flow direction. Stretched, the stretched film exiting from the stretching machine was removed from the clip, and both ends were continuously trimmed to obtain a base film having a width of 700 mm.

  Both sides of the film substrate are subjected to corona discharge treatment, a 5% polyvinyl alcohol aqueous solution is applied to one side of the film using a # 2 wire bar, the coating film is dried, and the film has an orientation of 0.1 μm. A film was formed. Next, the alignment film was rubbed to prepare a transparent resin substrate film having the alignment film.

(3-2: Preparation of circularly polarized light separating sheet having concavo-convex structure)
A transparent resin substrate having the alignment film prepared in (3-1) above using the same cholesteric liquid crystal composition as that prepared in the step (P1-2) of Production Example 1 using a # 4 wire bar The film was applied to the surface having an alignment film. The coating film was dried at 100 ° C. for 5 minutes and subjected to orientation aging. The coating film was further irradiated with ultraviolet rays of 1.0 mJ / cm ² (UV-A: 365 nm ± 5 nm), held at 100 ° C. for 1 minute, and then irradiated with ultraviolet rays of 500 mJ / cm ² to cure the coating film, A circularly polarized light separating sheet in which a selective reflection layer 131 having a dry film thickness of 2 μm was provided on a base film 132 through an alignment film was produced.

  Next, the surface of the thin film was rubbed in the film flow direction. When observed with a scanning electron microscope, linear scratches along the film flow direction were uniformly attached to the surface of the thin film. Next, the laminated film was passed through a hot air dryer in which hot air having a temperature of 140 ° C. was circulated, and contracted at a contraction rate ΔL = 20% in the main contraction direction.

  When the shrink film was observed with a field emission scanning electron microscope S-4700 manufactured by Hitachi, a fine uneven shape elongated in a stripe shape was uniformly formed on the surface.

(3-3: Production of organic EL light source device)
The circularly polarized light separating sheet having the concavo-convex structure obtained in (3-2) above was attached to an organic EL element to produce an organic EL light source device.

It is sectional drawing which shows schematically the organic electroluminescent light source device which concerns on one Embodiment of this invention. It is a graph which shows the relationship between the transmission wavelength and the transmittance | permeability in various observation angles of the selective reflection layer in the organic electroluminescent light source device shown in FIG. It is a graph which shows the light emission spectrum of the light emitting element in the organic electroluminescent light source device shown in FIG. 2 is a graph showing a light distribution of blue light and yellow light emitted from a substrate 101 in the organic EL light source device shown in FIG. 1. 2 is a graph showing a light distribution of blue light and yellow light emitted from a light exit surface 109 in the organic EL light source device shown in FIG. It is a graph which shows the relationship between the incident angle of blue light, and a reflectance of the selective reflection layer in the organic electroluminescent light source device shown in FIG. It is a graph which shows the relationship between the incident angle of yellow light and the reflectance of the selective reflection layer in the organic EL light source device shown in FIG. It is sectional drawing which shows schematically the organic electroluminescent light source device which concerns on another one Embodiment of this invention. 3 is a graph showing a light distribution of blue light and yellow light emitted from a substrate 101 in the organic EL light source device shown in FIG. It is a graph which shows the light distribution of the blue light and the yellow light which radiate | emit from the base film 132 in the organic electroluminescent light source device shown in FIG. It is sectional drawing which shows schematically the organic electroluminescent light source device which concerns on another one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Substrate 111 Transparent electrode 112 Reflective electrode 121 Light emitting layer 131 Selective reflective layer 132 Base film 841, 1141, 1241 Diffusion layer 1251 Adhesive layer 1252, 1352 Base film 1361 Structure

Claims (6)

An organic electroluminescence light-emitting element;
A selective reflection layer disposed on the light emission side of the organic electroluminescence light-emitting element,
The organic electroluminescence light-emitting element has an organic light-emitting layer having two or more emission intensity peaks,
The selective reflection layer, the selective reflection bandwidth of the front direction of the transmitted light, viewed contains at least one peak wavelength of the emission intensity peak,
The selective reflection layer has a transmittance ^T _{F Y} in the front direction of the wavelength 575 _{nm, N,} the average value ^T _{F Y} polar angle 60 ° direction of the transmission at a wavelength of 575 _{nm, 60,} the front direction of the transmittance at a wavelength of 480 nm ^{T F} The average value T ^F _{B, 60} of the transmittance in the direction of polar angle 60 ° of _{B, N} and wavelength 480 nm is the formula [1]:
_{^{(T F Y, 60 / T}} F Y, N)> (T F B, 60 / T F B, N) formula (1)
An organic electroluminescence light source device characterized by satisfying the above relationship . The organic electroluminescence light source device according to claim 1,
An organic electroluminescence light source device further comprising a light scattering layer. The organic electroluminescence light source device according to claim 1 or 2,
Furthermore, an organic electroluminescence light source device comprising an uneven structure layer.   The organic electroluminescence light source device according to any one of claims 1 to 3,
  The organic electroluminescence light source device, wherein the selective reflection layer has one or more selective reflection bands in a wavelength range of 500 nm to 650 nm as a selective reflection band of transmitted light in a front direction.   It is an organic electroluminescent light source device of any one of Claims 1-4, Comprising:
  The organic electroluminescence light source device, wherein the selective reflection layer has one or more selective reflection bands in a wavelength range of 400 nm to 550 nm as a selective reflection band of transmitted light having a polar angle of 60 °.   It is an organic electroluminescent light source device of any one of Claims 1-5,
  The organic electroluminescence light-emitting device, wherein the organic electroluminescence light-emitting element has a light emission intensity peak in a wavelength range of 550 nm to 600 nm.

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