JP2013134833A - Optical laminate and surface light source device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical laminate having sufficient surface hardness, high interlayer adhesion and high durability, and to provide a surface light source device including the same.SOLUTION: An optical laminate 100 includes an easy adhesion layer 101 provided on the surface of a substrate 121, and a hardened layer 111 provided in direct contact therewith. The easy adhesion layer is a layer formed of a composition X containing urethane resin, and the hardened layer is formed by hardening a composition Y containing a monomer A, a monomer B and a photopolymerization initiator. The monomer A contains one or more isocyanate group per molecule, and one or more polymerizable unsaturated group per molecule. Monomer B has three or more polymerizable unsaturated groups per molecule, and does not contain isocyanate group. The photopolymerization initiator has a melting point of 100°C or lower, and has an absorption coefficient of 2.0×10(ml/g cm in MeOH) or less in a 365nm wavelength band.

Description

  The present invention relates to an optical laminate and a surface light source device including the same.

2. Description of the Related Art Conventionally, an optical laminate is widely used as a member constituting an optical device such as a display device, a light source device, and a lighting fixture. For example, for the purpose of improving the light extraction efficiency of a light source device having a light emitting element such as an organic electroluminescence (EL) element, it has been proposed to provide a light extraction film formed by curing an acrylic resin on the surface of the light emitting element. (Patent Document 1).
Further, when an acrylic resin layer is provided on the alicyclic olefin resin film layer, urethane is interposed between the acrylic resin layer and the alicyclic olefin resin film layer for the purpose of improving the adhesion. Providing a predetermined layer containing resin has also been proposed (Patent Document 2).

International Publication No. 2009/081750 JP 2009-274390 A

When an alicyclic olefin resin film with high gas barrier performance is employed to effectively seal the organic EL element, and a light extraction film is further provided on the alicyclic olefin resin film, the light extraction film is good with the alicyclic olefin resin film. It is necessary to be in close contact with the surface and sufficient surface hardness is also required.
However, the acrylic resin having a sufficient surface hardness found in the prior art is an alicyclic olefin resin having sufficient adhesion even when the easy-adhesion layer described in Patent Document 2 is used. There is a problem that it cannot be adhered to the film.
In particular, when a film provided with a concavo-convex structure layer for increasing the light extraction efficiency is employed as the light extraction film, it is necessary to use a material having a high hardness as the material of such a film in order to prevent loss of the concavo-convex structure. Nothing has been found that has such a high hardness and can be adhered to the alicyclic olefin resin film with sufficient adhesion.

  Accordingly, an object of the present invention is to provide an optical laminate having a sufficient surface hardness, and having high adhesion between the layers constituting the laminate and high durability.

  Another object of the present invention is a surface light source device including an organic EL element, which provides a surface light source device having high light extraction efficiency, high surface hardness, hardly delamination between layers, and high durability. There is.

As a result of studies by the present inventors to solve the above-described problems, a predetermined easy-adhesion layer is provided between the base material and the cured layer in the optical laminate having the base material and the effect layer for extracting light. In addition to providing the above, the inventors have found that the above-mentioned problems can be solved by setting the material of the hardened layer to a predetermined material, and the present invention has been completed.
That is, according to the present invention, the following is provided.

[1] An optical laminate comprising a base material, an easy-adhesion layer provided on the surface of the base material, and a cured layer provided in direct contact with the easy-adhesion layer,
The easy adhesion layer is a layer formed of the composition X containing a urethane resin,
The cured layer is a layer formed by curing a composition Y containing monomer A, monomer B and a photopolymerization initiator,
The monomer A is a monomer containing one or more isocyanate groups per molecule and one or more polymerizable unsaturated groups per molecule,
The monomer B is a monomer having 3 or more polymerizable unsaturated groups per molecule and not containing an isocyanate group,
The optical polymerization initiator is a photopolymerization initiator having a melting point of 100 ° C. or lower and having an extinction coefficient of 2.0 × 10 ² (ml / g · cm in MeOH) or more in a 365 nm wavelength band. body.

[2] In the optical laminate according to [1],
In the composition Y, an optical layered body in which the content ratio of isocyanate groups in the total amount of monomers is 0.25 mmol / g or more, and the ratio of the monomer B in the total amount of monomers is 15% by weight or more.
[3] In the optical laminate according to [1] or [2],
The hardened layer is an optical laminate having a concavo-convex structure provided on a surface opposite to a surface in contact with the easy-adhesion layer.

[4] In the optical laminate according to [3],
The cured layer is
Applying the composition Y on the easy-adhesion layer to obtain a coating film,
With the mold applied to the coating film, the composition Y is cured by irradiating the coating film with light through the base material and the easy-adhesion layer,
An optical laminate formed by peeling the mold.
[5] In the optical laminate according to any one of [1] to [4],
The hardened layer is an optical laminate containing particles.

[6] In the optical laminate according to any one of [1] to [5],
The easy adhesion layer is an optical laminate containing silica particles.
[7] In the optical laminate according to any one of [1] to [6],
The composition X is an optical laminate including the urethane resin as a water-based urethane resin.
[8] A surface light source device including an organic electroluminescence light-emitting element,
The surface light source device further provided with the optical laminated body in any one of [1]-[7] in the light emission surface side rather than the said organic electroluminescent light emitting element.

  The optical layered body of the present invention has high adhesion between the base material and the cured layer through the easy-adhesion layer, and the surface hardness of the cured layer is sufficiently high. be able to. Furthermore, when the alicyclic structure-containing polymer resin is used as the base material, the gas barrier performance of the alicyclic structure-containing polymer resin can be further exhibited while having the above-described characteristics. And deterioration of the device over time can be suppressed. In addition, since the surface light source device of the present invention includes the optical layered body of the present invention, the optical layered body can increase the light extraction efficiency, has a high surface hardness, is difficult to cause delamination, and has a simple structure. And can be a device having high durability.

FIG. 1 is a perspective view schematically showing an example of the optical layered body of the present invention provided with a cured layer having an uneven structure. FIG. 2 is a cross-sectional view showing a cross section of the optical laminate shown in FIG. 1 cut along a plane passing through line 1a-1b. FIG. 3 is a partial top view schematically showing an enlarged structure of the surface of the light diffusion layer of the optical laminate shown in FIG. FIG. 4 is a partial cross-sectional view showing a cross section of the light diffusion layer shown in FIG. 3 cut along a plane that passes through the line 10a of FIG. 3 and is perpendicular to the main surface of the optical laminate. FIG. 5 is a perspective view schematically showing an example of the surface light source device of the present invention. FIG. 6 is a cross-sectional view showing a cross section of the surface light source device 10 shown in FIG. 5 taken along a plane passing through the line 1a-1b in FIG. 5 and perpendicular to the surface direction of the base material.

〔Overview〕
The optical layered body of the present invention includes a base material, an easy-adhesion layer provided on the surface of the base material, and a cured layer provided in direct contact with the easy-adhesion layer.

〔Base material〕
As a base material used for this invention, the arbitrary films which can be used as a component of an optical laminated body can be used. As the material for the film that can be used as the substrate, specifically, an alicyclic structure-containing polymer resin is preferable from the viewpoints of adhesion with an easy-adhesion layer, strength as a member of an optical laminate, transparency, and the like. In addition, polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, polycarbonate, (meth) acrylic resin, and the like can be given.

[Substrate: Polymer resin containing alicyclic structure]
The alicyclic structure-containing polymer resin is a resin containing an alicyclic structure-containing polymer and other optional components as required.

  The alicyclic structure-containing polymer has an alicyclic structure in the main chain and / or side chain, and is usually an amorphous thermoplastic polymer. Examples of the alicyclic structure in the alicyclic structure-containing polymer include a saturated alicyclic hydrocarbon (cycloalkane) structure and an unsaturated alicyclic hydrocarbon (cycloalkene) structure. From the viewpoint, a cycloalkane structure is preferable. The number of carbon atoms constituting the alicyclic structure is not particularly limited, but is usually 4 to 30, preferably 5 to 20, more preferably 5 to 15, when the mechanical strength, heat resistance, In addition, the moldability characteristics of the film are highly balanced and suitable.

  The ratio of the repeating unit having an alicyclic structure constituting the alicyclic structure-containing polymer is preferably 55% by weight or more, more preferably 70% by weight or more, and particularly preferably 90% by weight or more. It is preferable from a viewpoint of transparency and heat resistance that the ratio of the repeating unit which has an alicyclic structure in an alicyclic structure containing polymer exists in this range.

  Examples of the alicyclic structure-containing polymer include norbornene polymers, monocyclic olefin polymers, cyclic conjugated diene polymers, vinyl alicyclic hydrocarbon polymers, and hydrides thereof. Among these, norbornene polymers can be suitably used because of their good transparency and moldability.

Examples of the norbornene polymer include a ring-opening polymer of a monomer having a norbornene structure, a ring-opening copolymer of a monomer having a norbornene structure and another monomer, or a hydride thereof; norbornene structure Or an addition copolymer of a monomer having a norbornene structure with another monomer, or a hydride thereof. Among these, a ring-opening (co) polymer hydride of a monomer having a norbornene structure is particularly suitable from the viewpoints of transparency, moldability, heat resistance, low hygroscopicity, dimensional stability, lightness, and the like. Can be used.
As the alicyclic structure-containing polymer, the alicyclic structure-containing polymer resin may contain only one kind of these polymers alone, or may contain two or more kinds in combination at any ratio. Also good.

  The molecular weight of the alicyclic structure-containing polymer contained in the alicyclic structure-containing polymer resin is appropriately selected according to the purpose of use, but using cyclohexane as a solvent (provided that the polymer does not dissolve in cyclohexane) May be toluene) The weight average molecular weight (Mw) in terms of polyisoprene measured by gel permeation chromatography (in terms of polystyrene when the solvent is toluene), usually 10,000 or more, preferably 15 50,000 or more, more preferably 20,000 or more, and usually 100,000 or less, preferably 80,000 or less, more preferably 50,000 or less. When the weight average molecular weight is in such a range, the mechanical strength and molding processability of the obtained substrate are highly balanced, which is preferable.

Examples of optional components that can be contained in the alicyclic structure-containing polymer resin include antioxidants, heat stabilizers, light stabilizers, ultraviolet absorbers, antistatic agents, dispersants, chlorine scavengers, flame retardants, and crystals. Nucleating agents, reinforcing agents, antiblocking agents, antifogging agents, mold release agents, pigments, organic or inorganic fillers, neutralizing agents, lubricants, decomposition agents, metal deactivators, antifouling agents, antibacterial agents, Known additives such as other resins and thermoplastic elastomers can be listed.
The amount of these additives can be within a range that does not impair the effects of the present invention. For example, it is 0-50 weight part normally with respect to 100 weight part of polymers contained in alicyclic structure containing polymer resin, Preferably it is 0-30 weight part.

[Shape and physical properties of substrate]
The material constituting the substrate is preferably a material having high transparency. For example, it is preferable that the total light transmittance measured by using the material as a test piece having a thickness of 1 mm is usually 70% or more, preferably 80% or more, and more preferably 90% or more.

  Although the thickness of a base material is not specifically limited, The minimum can be 10 micrometers or more. Moreover, the upper limit can be 500 micrometers or less.

  The substrate is preferably a long film from the viewpoint of production efficiency. Here, the “long” means one having a length of at least 5 times the width, preferably 10 times or more, specifically in the form of a roll. It has a length that can be wound and stored or transported. It is efficient by forming a base film as a long film, continuously forming an easy-adhesion layer and a cured layer thereon, and cutting the resulting long optical laminate into a desired shape as necessary. Manufacturing can be performed.

  The substrate may be composed of a single layer or may be composed of a plurality of layers. When the substrate is composed of a plurality of layers, the substrate may be a laminate of a plurality of films with an adhesive or a pressure-sensitive adhesive, and a plurality of layers made of different materials depending on a production method such as coextrusion. May be formed. Further, the substrate may be isotropic without undergoing an operation such as stretching, or may be provided with anisotropy by an operation such as stretching.

[Production method of substrate]
Although the manufacturing method of a base material is not specifically limited, For example, it can obtain by shape | molding the above-mentioned resin etc. with a well-known film forming method. Examples of the film forming method include a cast forming method, an extrusion forming method, and an inflation forming method. Among them, the melt extrusion method without using a solvent is preferable because the amount of residual volatile components can be efficiently reduced, the environmental load is low, the manufacturing operation is easy, and the manufacturing efficiency is high. Examples of the melt extrusion method include an inflation method using a die, and a method using a T die is preferable in terms of excellent productivity and thickness accuracy.

[Easily adhesive layer]
The easy-adhesion layer is a layer that is provided between the substrate and the cured layer and improves the adhesion between the substrate and the cured layer. The easy adhesion layer is preferably provided in direct contact with the surface of the substrate. You may provide functional layers, such as an antistatic layer and a diffusivity provision layer, between a base material and an easily bonding layer.

[Composition X: water-based urethane resin]
The easy adhesion layer is a layer formed of the composition X containing a urethane resin. In a preferred embodiment, the composition X contains a urethane resin as a water-based urethane resin. The water-based urethane resin is a urethane resin that can exist in a form dispersed in a water-based medium such as water.

  Examples of the water-based urethane resin include (i) a water-based urethane resin obtained by reacting a component containing two or more active hydrogens in one molecule on average with (ii) a polyvalent isocyanate component, or the above (i ) Component and (ii) component are urethanated in an organic solvent which is inert to the reaction and has a high affinity for water under the condition of excess isocyanate group to obtain an isocyanate group-containing prepolymer, Examples thereof include water-based urethane resins produced by chain extension using a sum, chain extender, and addition of water to form a dispersion. These water-based urethane resins may contain an acid component (acid residue). The isocyanate group may be masked with a blocking agent (phenols, caprolactams, oximes, active methylenes, hydrazines, etc.). Among these, active methylenes and hydrazines are particularly preferable because the dissociation temperature of the blocking agent is low.

The chain extension method of the isocyanate group-containing prepolymer may be a known method. For example, water, a water-soluble polyamine, glycols or the like is used as the chain extender, and the isocyanate group-containing prepolymer and the chain extender component are used. May be reacted in the presence of a catalyst as necessary.

The component containing an average of 2 or more active hydrogens in one molecule of the component (i) is not particularly limited, but preferably has a hydroxylic active hydrogen. Specific examples of such compounds include the following.

(1) Diol compound Examples of the diol compound include ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, and 1,4-butylene glycol. 1,5-pentanediol, neopentyl glycol, 1,6-hexane glycol, 2,5-hexanediol, dipropylene glycol, 2,2,4-trimethyl-1,3-pentanediol, tricyclodecane dimethanol 1,4-cyclohexanedimethanol, 2,2-dimethylpropanediol, 1,4-butanediol and the like.

(2) Polyether diol As the polyether diol, for example, an alkylene oxide adduct of the above-mentioned diol compound; a ring-opening (co) polymer of an alkylene oxide and a cyclic ether (eg, tetrahydrofuran); polyethylene glycol, polypropylene glycol, ethylene Examples include glycols such as a glycol-propylene glycol copolymer, glycol, polytetramethylene glycol, polyhexamethylene glycol, and polyoctamethylene glycol.

(3) Polyester diol As the polyester diol, for example, dicarboxylic acid such as adipic acid, succinic acid, sebacic acid, glutaric acid, maleic acid, fumaric acid, phthalic acid or the anhydride thereof and those mentioned in the above (1) Obtained by polycondensation with diol compounds such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,8-octamethylenediol, neopentylglycol and the like under conditions of excess hydroxyl group Etc. More specifically, for example, ethylene glycol-adipic acid condensate, butanediol-adipine condensate, hexamethylene glycol-adipic acid condensate, ethylene glycol-propylene glycol-adipic acid condensate, or lactone with glycol as an initiator. And polylactone diol obtained by ring-opening polymerization.

(4) Polyether ester diol As the polyether ester diol, for example, an ether group-containing diol (for example, the polyether diol or diethylene glycol of (2) above) or a mixture of this and other glycols in the above (3) Examples include those obtained by reacting an alkylene oxide in addition to the exemplified dicarboxylic acid or its anhydride (for example, polytetramethylene glycol-adipic acid condensate).

(5) Polycarbonate diol Examples of the polycarbonate diol include, for example, the general formula: HO—R— (O—C (O) —O—R) x—OH (wherein R is a carbon atom having 1 to 12 carbon atoms). A saturated fatty acid diol residue, x represents the number of repeating units of the molecule, and is usually an integer of 5 to 50). These include a transesterification method in which a saturated aliphatic diol and a substituted carbonate (diethyl carbonate, diphenyl carbonate, etc.) are reacted under the condition that the hydroxyl group is excessive, the saturated aliphatic diol and phosgene are reacted, or as necessary. Then, it can be obtained by a method of further reacting with a saturated aliphatic diol.

  The compounds as exemplified in the above (1) to (5) may be used alone or in combination of two or more.

  As the (ii) polyvalent isocyanate component to be reacted with the component (i), an aliphatic, alicyclic or aromatic compound containing an average of two or more isocyanate groups in one molecule can be used.

  The aliphatic diisocyanate compound is preferably an aliphatic diisocyanate having 1 to 12 carbon atoms, and examples thereof include hexamethylene diisocyanate, 2,2,4-trimethylhexane diisocyanate, and hexane diisocyanate (HDI). The alicyclic diisocyanate compound is preferably an alicyclic diisocyanate having 4 to 18 carbon atoms, such as 1,4-cyclohexane diisocyanate, methylcyclohexylene diisocyanate, isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate (HMDI), and the like. Can be mentioned. Examples of the aromatic isocyanate include tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and xylylene diisocyanate.

  In addition, those containing an acid residue in the water-based urethane resin can be dispersed in water without using a surfactant (hereinafter also referred to as an emulsifier) or in a small amount. Therefore, it is expected that the water resistance of the coating film is improved. This is called a self-emulsifying type, and means a state in which the polyurethane resin is dispersed and stabilized in water only by molecular ionicity without using a surfactant. Since a surfactant is unnecessary, it is preferable because it has excellent adhesion to alicyclic structure-containing polymers, (meth) acrylic resins, and polyester resins, and can maintain high transparency. The acid residue content is 20 to 250 mgKOH / g, preferably 25 to 150 mgKOH / g, as the acid value of the water-based urethane resin. If the acid value is less than 20, water dispersibility tends to be insufficient, and it is often necessary to use a surfactant. On the other hand, if the acid value is greater than 250, the water resistance of the coating tends to be poor. In the present application, “(meth) acryl” means acryl and / or methacryl. Similarly, “(meth) acrylate” means acrylate and / or methacrylate.

  As a method for introducing an acid group into a water-based urethane resin, a conventionally used method can be used without any particular limitation. For example, dimethylolalkanoic acid is a part of the glycol component described in (2) to (4) above. Or the method of introduce | transducing an acid group by introduce | transducing a carboxyl group to polyether diol, polyester diol, polyether ester diol, etc. previously by replacing with all is preferable. Examples of the dimethylol alkanoic acid used here include dimethylol acetic acid, dimethylol propionic acid, and dimethylol butyric acid.

  Moreover, since the water dispersibility of water based urethane resin can be improved by neutralizing the acid component which remains in water based urethane resin, it is preferable to neutralize. Examples of the neutralizing agent that neutralizes the acid component include organic amines such as trimethylamine, triethylamine, tripropylamine, tributylamine, N-methyldiethanolamine, and triethanolamine, and inorganic such as sodium hydroxide, potassium hydroxide, and ammonia. Examples include bases.

  The water-based urethane resin preferably has a number average molecular weight of 1,000 or more, more preferably 20,000 or more. However, it is preferably 1,000,000 or less, more preferably 200,000 or less.

  In the production method of the present invention, it is also possible to use a commercially available aqueous urethane resin as an aqueous urethane resin as it is, for example, “Adekabon titer” series manufactured by Asahi Denka Kogyo Co., Ltd., Mitsui Toatsu Chemicals, Inc. "Olestar" series manufactured by Dainippon Ink & Chemicals, Inc. "Bondic" series, "Hydran" series manufactured by Dainippon Ink and Chemicals, "Imprunil" series manufactured by Bayer, "Sofuranate" series, "Poise" series manufactured by Kao Corporation, "Samprene" series manufactured by Sanyo Chemical Industries, Ltd., "Izelux" series manufactured by Hodogaya Chemical Co., Ltd., Daiichi Kogyo Seiyaku Co., Ltd. "Superflex" series, "Elastron" series made by Zeon, and "Neolet" series made by Zeneca Co., Ltd. can be used.

[Composition X: Other components]
The easy adhesion layer may contain silica particles. In order to obtain such an easy-adhesion layer, the composition X for forming the easy-adhesion layer may contain silica particles. When the easy-adhesion layer contains silica particles, a multi-layered product consisting of a base material and an easy-adhesion layer is prepared in the production of the optical layered body of the present invention, and this is made into a roll state for the convenience of storage or transportation. Quality deterioration at the time can be reduced.
Examples of the silica particles include a spherical shape, an elliptical shape, and a structure in which the particles are connected in a network shape. The particle size of the silica particles can be about 50 nm to 200 nm. It is preferable that the content rate of the silica particle in the composition X is 5-30 weight part with respect to 100 weight part (solid content) of water-system urethane resin. By setting it as such a ratio, the above-described effect of reducing the quality deterioration can be satisfactorily exhibited without impairing the performance of the optical laminate.

  In addition to the water-based urethane resin and the optional silica particles, the composition X can contain an appropriate amount of optional components as necessary. Such optional components include heat stabilizers, weather stabilizers, leveling agents, antistatic agents, slip agents, antiblocking agents, organotin reaction catalysts, antifogging agents, lubricants, dyes, pigments, natural oils, synthetic oils. , Waxes, crosslinkers, and water and other media.

  When the thickness of the easy-adhesion layer formed on the base material used in the present invention is 1 μm or less, the composition X preferably contains a crosslinking agent for the purpose of improving the mechanical strength of the easy-adhesion layer. As the crosslinking agent, any compound having a functional group that reacts with the reactive group of the water-based urethane resin can be used without particular limitation, but water-based epoxy compounds, water-based amino compounds, water-based isocyanate compounds, water-based carbodiimide compounds. It is preferable to use an aqueous oxazoline compound from the viewpoint of versatility of the material, and particularly preferable to use an aqueous epoxy compound, an aqueous amino compound, and an aqueous oxazoline compound from the viewpoint of adhesiveness.

  When using a water-based epoxy compound as a crosslinking agent, the water-based epoxy compound may be a compound that is soluble in water or has two or more epoxy groups emulsified. For example, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol; 1 mol of glycol such as 1,4-butanediol, 1,6-hexane glycol, neopentyl glycol and 2 mol of epichlorohydrin Diepoxy compounds obtained by etherification, polyepoxy compounds obtained by etherification of 1 mol of polyhydric alcohols such as glycerin, polyglycerin, trimethylolpropane, pentaerythritol, sorbitol and 2 mol or more of epichlorohydrin, phthalic acid, terephthalic acid Epoxidation of diepoxy compounds obtained by esterification of 1 mol of dicarboxylic acid such as oxalic acid, adipic acid and 2 mol of epichlorohydrin Thing, and the like.

  When an aqueous amino compound is used as the cross-linking agent, the aqueous amino compound may be any compound that is soluble in water or has two or more amino groups emulsified. For example, carbodihydrazide, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, dodecanedioic acid dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrazide, acrylic acid dihydrazide Examples thereof include compounds, melamine resins, urea resins, and guanamine resins.

  When a water-based isocyanate compound is used as a crosslinking agent, the water-based isocyanate compound is soluble in water or an emulsified compound having two or more non-blocked isocyanate groups or block-type isocyanate groups. Good. Examples of the non-blocking isocyanate compound include compounds obtained by reacting a polyfunctional isocyanate compound with a monovalent or polyvalent nonionic polyalkylene ether alcohol. Examples of the block isocyanate compound include 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), 4,4′-diphenylmethane diisocyanate (MDI), Xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), methylcyclohexyl diisocyanate (H6TDI), 4,4'-dicyclohexylmethane diisocyanate (H12MDI), 1,3-bis (isocyanatomethyl) cyclohexane (H6XDI), tetramethylxylylene Range isocyanate (TMXDI), 2,2,4-trimethylhexamethylene diisocyanate (TMHDI), hexamethylene diisocyanate (HDI), norbornene diisocyanate (NBDI) ), 2,4,6-triisopropylphenyl diisocyanate (TIDI), 1,12-diisocyanatododecane (DDI), 2,4, -bis- (8-isocyanatooctyl) -1,3-dioctylcyclobutane (OCDI), n-Pentane-1,4-diisocyanate and their isocyanurate-modified products, adduct-modified products, burette-modified products, allophanate-modified products, and those polymers having one or more isocyanate groups are polyoxyalkylene groups, carboxyls And compounds obtained by modification with a group, etc., making it water-soluble and / or water-dispersible, and masking the isocyanate group with a blocking agent (phenols, caprolactams, oximes, active methylenes, hydrazines, etc.) .

  When an aqueous carbodiimide compound is used as a crosslinking agent, the aqueous carbodiimide compound may be a compound that is soluble in water or has two or more carbodiimide bonds (-N = C = N-) emulsified. . A compound having two or more carbodiimide bonds is obtained by a method in which two isocyanate groups are decarboxylated to form -N = C = N- using two or more molecules of polyisocyanate and a carbodiimidization catalyst. be able to. The polyisocyanate and the carbodiimidization catalyst used when producing a compound having two or more carbodiimide bonds are not particularly limited, and conventionally known ones can be used.

  The water-based oxazoline compound may be any compound that is soluble in water or has two or more oxazoline groups emulsified.

  The ratio of the water-based urethane resin and the crosslinking agent in the composition X is 1 to 70 parts by weight, preferably 5 to 60 parts by weight (solid content), based on 100 parts by weight (solid content) of the water-based urethane resin. It is preferable to do. By adopting such a composition, it becomes possible to achieve both the strength of the coating film and the stability of the coating solution.

[Method for preparing composition X, properties]
The preparation method of the composition X is not specifically limited, For example, it can obtain by mixing the said component.
The composition X can be an aqueous dispersion in which a solid content of an aqueous urethane resin is dispersed in water to constitute an emulsion, a colloidal dispersion system, or the like. The particle size of the water-based urethane resin particles dispersed in the aqueous dispersion is preferably 0.01 μm to 0.4 μm from the viewpoint of the optical properties of the optical laminate. The particle size of the water-based urethane resin particles can be measured by a dynamic light scattering method, and for example, can be measured by a light scattering photometer DLS-8000 series manufactured by Otsuka Electronics Co., Ltd. The composition X may contain a water-soluble solvent other than water. Examples of the water-soluble solvent include methanol, ethanol, isopropyl alcohol, acetone, tetrahydrofuran, N-methylpyrrolidone, dimethyl sulfoxide, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, and the like.

  The viscosity of the composition X is preferably 15 mPa · s or less, and particularly preferably 10 mPa · s or less. When the viscosity of the dispersion is within the above range, the composition X can be uniformly applied to the surface of the substrate. The viscosity of the composition X is a value measured under a condition of 25 ° C. with a tuning fork type vibration viscometer, and by changing the ratio of the aqueous urethane resin in the composition X, the particle size of the aqueous urethane resin, and the like, The viscosity of the composition X can be adjusted.

[Properties of easy-adhesion layer and formation method]
The easy adhesion layer preferably has a pencil hardness of H or more at a thickness of 20 μm. By setting it in the above range, scratch resistance can be imparted to the optical laminate.

  The easy-adhesion layer is cured by, for example, applying the composition X on the surface of the base material to form a coating film (layer of the composition X in a liquid state) and drying it as necessary. Can be formed.

  Before providing the easy-adhesion layer, the surface of the base material on which the easy-adhesion layer is provided may be modified to further improve the adhesion between the base material and the easy-adhesion layer. Examples of the surface modification treatment for the substrate include energy ray irradiation treatment and chemical treatment. Examples of the energy ray irradiation treatment include corona discharge treatment, plasma treatment, electron beam irradiation treatment, and ultraviolet ray irradiation treatment. From the viewpoint of processing efficiency, corona discharge treatment and plasma treatment are preferred, and corona discharge treatment is particularly preferred. Examples of the chemical treatment include saponification treatment, dipping in an aqueous oxidizing agent solution such as potassium dichromate solution, concentrated sulfuric acid, and then washing with water.

  The method for applying the composition X on the substrate is not particularly limited, and a known application method can be employed. Specific coating methods include wire bar coating, dipping, spraying, spin coating, roll coating, gravure coating, air knife coating, curtain coating, slide coating, and extrusion coating. Can be mentioned. The coating amount of the composition X is not particularly limited, but the thickness after drying is preferably 0.01 to 5 μm, more preferably 0.02 to 2 μm, and particularly preferably 0.03 to 1 μm. Within the above range, sufficient adhesive strength between the substrate and the easy-adhesion layer can be obtained, and an optical laminate having no defects such as warping of the film can be provided.

  Although the method of hardening the coating film of the composition X is not specifically limited, For example, it can be hardened by drying at the temperature of about 80 to 130 degreeC.

[Curing layer]
In the present invention, the hardened layer is a layer provided in direct contact with the easy-adhesion layer. The cured layer is a layer formed by curing a composition Y containing monomer A, monomer B, and a photopolymerization initiator.

[Components of Composition Y]
In composition Y, monomer A is a monomer containing one or more isocyanate groups per molecule and one or more polymerizable unsaturated groups per molecule. Monomer B is a monomer having 3 or more polymerizable unsaturated groups per molecule and no isocyanate group. When the composition Y contains the monomers A and B, the cured layer formed by curing the composition Y can have both high adhesion with the easy-adhesion layer and high surface hardness.

  Examples of such polymerizable unsaturated groups include (meth) acryloyl groups and vinyl groups.

  Specific examples of the monomer A include (meth) acryloyl isocyanate, 2- (meth) acryloyloxyethyl isocyanate, 3- (meth) acryloyloxypropyl isocyanate, 2- (meth) acryloyloxy-1-methylethyl isocyanate, 2- (Meth) acryloyloxy-2-methylethyl isocyanate, 1,1-bis [(meth) acryloyloxymethyl] ethyl isocyanate, and m- (meth) acryloyloxyphenyl isocyanate. Among these, 2- (meth) acryloyloxyethyl isocyanate and 1,1-bis [(meth) acryloyloxymethyl] ethyl isocyanate are considered from the viewpoints of handleability, chemical stability, and industrial availability. Is preferred.

  Specific examples of the monomer B include glycerin tri (meth) acrylate, glycerin alkylene oxide tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane ethoxytri (meth) acrylate, and trimethylolpropane polyalkylene oxide tri. (Meth) acrylate, trimethylolpropane tricaprolactonate tri (meth) acrylate, trimethylolethane tri (meth) acrylate, trimethylolethane polyalkylene oxide tri (meth) acrylate, trimethylolhexanetri (meth) acrylate, trimethylol Hexane polyalkylene oxide tri (meth) acrylate, trimethylol octane tri (meth) acrylate, trimethylol alcohol Tan polyalkylene oxide tri (meth) acrylate, pentaerythritol tri (meth) acrylate, trihydroxybenzene (such as pyrogallol) polyalkylene oxide adduct triacrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol polyalkylene oxide tetra (meth) Acrylate, pentaerythritol tetracaprolactonate tetra (meth) acrylate, diglycerin tetra (meth) acrylate, diglycerin tri (meth) acrylate, diglycerin polyalkylene oxide tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate , Ditrimethylolpropane polyalkylene oxide tetra (meth) acrylate, isocyanuric acid O-modified tri (meth) acrylate, isocyanuric acid EO-modified tetra (meth) acrylate, ditrimethylolethane tetra (meth) acrylate, ditrimethylolethane polyalkylene oxide tetra (meth) acrylate, ditrimethylolbutanetetra (meth) acrylate, ditrimethylol Butane polyalkylene oxide tetra (meth) acrylate, ditrimethylol hexane tetra (meth) acrylate, ditrimethylol hexane polyalkylene oxide tetra (meth) acrylate, ditrimethylol octane tetra (meth) acrylate, ditrimethylol octane polyalkylene oxide tetra (meth) Acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa ( (Meth) acrylate, dipentaerythritol polyalkylene oxide penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol polyalkylene oxide hexa (meth) acrylate, dipentaerythritol hexacaprolactonate hexa (meth) acrylate , Tripentaerythritol hexa (meth) acrylate, tripentaerythritol hepta (meth) acrylate, tripentaerythritol octa (meth) acrylate, tripentaerythritol polyalkylene oxide hexa (meth) acrylate, tripentaerythritol polyalkylene oxide hepta (meth) Acrylate, tripentaerythritol polyalkylene oxide octa (meth) acrylate It can include various (meth) acrylate rates.

In the composition Y, a photopolymerization initiator is used as a polymerization initiator from the viewpoint of facilitating polymerization by a photopolymer method (2P method). The photopolymerization initiator is a polymerization initiator that develops an action when exposed to light (that is, in response to light irradiation). Here, the light for polymerization is not only visible light but also ultraviolet light, infrared light, And other energy rays. In particular, from the viewpoint of ease of operation, a polymerization initiator that is sensitive to visible light or ultraviolet light is particularly preferable. Moreover, it is preferable that a polymerization initiator is a radical polymerization initiator. The photopolymerization initiator used in the present invention is a photopolymerization initiator having an extinction coefficient of 2.0 × 10 ² (ml / g · cm in MeOH) or more in the 365 nm wavelength band. Among these, particularly preferable is an extinction coefficient of 4.0 × 10 ² (ml / g · cm in MeOH) or more, particularly preferably 1.0 × 10 ³ (ml / g · cm in MeOH) or more. . The upper limit of the extinction coefficient is 1.0 × 10 ⁵ (ml / g · cm in MeOH) or less, and particularly preferably 5.0 × 10 ⁴ (ml / g · cm in MeOH) or less. By using a photopolymerization initiator having an extinction coefficient within this range, the adhesiveness is good, and the working efficiency can be improved by increasing the curing rate.

  Specific examples of the radical polymerization initiator sensitive to visible light or ultraviolet light include 2,2-dimethoxy-1,2-diphenylethane-1-one (IRGACURE651), 2-methyl-1- [4- (methylthio) phenyl. ] -2-morpholinopropan-1-one (IRGACURE907), 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1 (IRGACURE369), 2-dimethylamino-2- (4-methyl) Acetophenone or derivatives thereof such as -benzyl) -1- (4-morpholin-4-yl-phenyl) -butan-1-one (IRGACURE 379); 4,4′-bis (dimethylamino) benzophenone, 4-benzoyl-4 Benzophenone or its derivatives such as' -methyldiphenyl sulfide; Zoin dimethyl ketal, 2,4,6-trimethylbenzoyldiphenylphosphine oxide (IRGACURE819), 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (Lucirin TPO), 1,2-octanedione, 1- [4- (Phenylthio)-, 2- (O-benzoyloxime)] (IRGACUREOXE1), ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O -Acetyloxime) (IRGACUREOXE2), bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide (CGI403), and the like.

  Among the photopolymerization initiators, those having a melting point of 100 ° C. or less are preferable. When the melting point is 100 ° C. or lower, there is an advantage that the solubility is increased even in a solvent-free composition. Those having a melting point of 60 ° C. or lower are more preferred, and the lower limit of the melting point is not particularly limited, but those having a melting point of −30 ° C. are preferred.

  The addition amount of the photopolymerization initiator is 3% by weight or more, preferably 4% by weight or more, based on the total amount of the composition Y in the cured layer in consideration of the polymerization rate and the like. The upper limit of the addition amount is not particularly limited, but is preferably 10% by weight or less in consideration of the adhesion and durability of the cured layer.

  In addition to the monomer A and the monomer B, the composition Y can contain any other monomer. Such optional monomers include a monomer having no isocyanate group and one polymerizable unsaturated group per molecule (hereinafter referred to as “monomer C”), and a monomer having no isocyanate group and having a polymerizable unsaturated group. Mention may be made of two monomers per molecule (hereinafter referred to as “monomer D”).

  Specific examples of the monomer C include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, Benzyl (meth) acrylate, methoxyethyl (meth) acrylate, methoxyethoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, ethoxyethoxyethyl (meth) acrylate, diethylene glycol mono (meth) acrylate, triethylene glycol mono (meth) Acrylate, dipropylene glycol mono (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxyethoxyethyl (meth) acrylate, p-tert-butylphenol Enoxyethoxyethyl (meth) acrylate, p-nonylphenoxyethoxyethyl (meth) acrylate, octylphenoxyethoxyethyl (meth) acrylate, ethoxylated phenylphenol (meth) acrylate, ethoxylated O-phenylphenol (meth) acrylate, Phenoxypolyethylene glycol (meth) acrylate, 2- (meth) acryloyloxyethyl succinate, dodecylphenoxyethoxyethyl (meth) acrylate, isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, tricyclo [5.2.1.02, 6] Various (meth) acrylates such as decane monomethylol (meth) acrylate and tetrahydrofurfuryl (meth) acrylate; diethylene glycol monovinyl ester Ter, 1,4-butanediol monovinyl ether, triethylene glycol monovinyl ether, hexaethylene glycol monovinyl ether, vinyl ethers such as 1,4-cyclohexanedimethanol monovinyl ether; N-vinylpyrrolidone, N-vinylformamide, N-acryloyl Mention may be made of N-vinylamide compounds such as morpholine.

  Specific examples of monomer D include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene Glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, pentyl glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, hydroxy Pivalyl hydroxypivalate di (meth) acrylate, hydroxypivalyl hydroxypivalate dicaprolactonate di (meth) acrylate, , 6-hexanediol di (meth) acrylate, tricyclodecane methanol di (meth) acrylate, tricyclodecane dimethylol di (meth) acrylate, tricyclodecane dimethylol dicaprolactonate di (meth) acrylate, isocyanuric acid EO Modified di (meth) acrylate, 9,9-bis (4- (meth) acryloyloxyphenyl) fluorene, 9,9-bis (3-methyl-4- (meth) acryloyloxyphenyl) fluorene, 9,9-bis (3-methyl-4- (2- (meth) acryloyloxyethoxy) phenyl) fluorene, bisphenol A tetraethylene oxide adduct di (meth) acrylate, bisphenol A polyalkylene oxide adduct di (meth) acrylate, bisphenol F tet Ethylene oxide adduct di (meth) acrylate, bisphenol F polyalkylene oxide adduct di (meth) acrylate, bisphenol S tetraethylene oxide adduct di (meth) acrylate, bisphenol S polyalkylene oxide adduct di (meth) acrylate, water Addition bisphenol A tetraethylene oxide adduct di (meth) acrylate, water addition bisphenol A polyalkylene oxide adduct di (meth) acrylate, water addition bisphenol F tetraethylene oxide adduct di (meth) acrylate, water addition bisphenol F polyalkylene Oxide adduct di (meth) acrylate, water added bisphenol A di (meth) acrylate, water added bisphenol F di (meth) acrylate, dihydroxy base Zen (catechol, resorcin, hydroquinone, etc.) polyalkylene oxide di (meth) acrylate, alkyldihydroxybenzene polyalkylene oxide di (meth) acrylate, bisphenol A tetraethylene oxide adduct dicaprolactonate di (meth) acrylate, bisphenol F tetra Ethylene oxide adduct dicaprolactonate di (meth) acrylate, tricyclo [5.2.1.02,6] decane dimethanol di (meth) acrylate, 1,4-cyclohexanedimethanol di (meth) acrylate, etc. Various acrylates; fumaric acid esters such as diethyl fumarate, diisobutyl fumarate, di-n-butyl fumarate; diethylene glycol divinyl ether, 1,4-butanediol divinyl ether , It may be mentioned triethylene glycol divinyl ether, hexaethylene glycol divinyl ether, a vinyl ether such as 1,4-cyclohexane dimethanol divinyl ether.

  In composition Y, the content of isocyanate groups in the total amount of monomers (total of monomer A, monomer B, and other arbitrary monomers such as monomer C and monomer D) is 0.25 mmol / g or more, and monomer The ratio of the monomer B in the total amount is preferably 15% by weight or more. By containing the isocyanate group and the monomer B in such a ratio, the composition Y can provide a cured layer having a high level of high adhesion with an easy adhesion layer based on isocyanate and high surface hardness based on crosslinking. it can.

  In the composition Y, it is preferable that the acid value in the total amount of monomers is within a predetermined range. Specifically, the upper limit of the acid value is preferably 5 mgKOH / g or less, and more preferably 3 mgKOH / g or less. The acid value of all the monomers can be determined from the acid value of each monomer and the ratio of each monomer contained in all the monomers. By setting the acid value in such a low range, the storage stability of the composition Y is improved, and the production of the cured layer is facilitated. That is, since it is difficult to cause a change in properties such as an increase in viscosity from the preparation of the composition Y to the use, there is a limitation in the process that the preparation of the composition Y must be performed immediately before use. Less.

The composition Y can contain optional components as necessary in addition to the monomer A, the monomer B, the polymerization initiator, and other optional monomers (such as the monomer C and the monomer D). Specifically, particles, solvents, matting agents, slip agents, antistatic agents, and surfactants can be contained.

  The cured layer preferably contains particles. In order to obtain such a preferred cured layer, the composition Y can contain particles. When the hardened layer contains particles, light can be diffused in the hardened layer, thereby improving the extraction efficiency.

  The particles may be transparent or opaque. As the material for the particles, metals, metal compounds, resins, and the like can be used. Examples of the metal compound include metal oxides and nitrides. Specific examples of metals and metal compounds include metals having high reflectivity such as silver and aluminum, and metal compounds such as silicon oxide, aluminum oxide, zirconium oxide, silicon nitride, tin-doped indium oxide, and titanium oxide. Can do. On the other hand, examples of the resin include methacrylic resin, polyurethane resin, and silicone resin. In particular, a silicone resin is particularly preferable from the viewpoints of dispersibility and wet heat resistance. In addition, the particle | grain material may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

The shape of the particles can be a spherical shape, a cylindrical shape, a cubic shape, a rectangular parallelepiped shape, a pyramid shape, a conical shape, a star shape, or the like.
The particle diameter of the particles is preferably 0.1 μm or more and 10 μm or less, more preferably 5 μm or less, and still more preferably 1 μm or less. Here, the particle diameter is a 50% particle diameter in an integrated distribution obtained by integrating the volume-based particle amount with the particle diameter as the horizontal axis. The larger the particle size, the larger the content ratio of particles necessary for obtaining the desired effect, and the smaller the particle size, the smaller the content. Therefore, as the particle size is smaller, desired effects such as a reduction in change in color depending on the observation angle and an improvement in light extraction efficiency can be obtained with fewer particles. When the particle shape is other than spherical, the diameter of the sphere having the same volume is used as the particle size.

  When the particles are transparent particles and the particles are contained in the resin, the difference between the refractive index of the particles and the refractive index of the resin is preferably 0.05 to 0.5. More preferably, it is 07-0.5. Here, either the particle or the refractive index of the resin may be larger. If the refractive index of the particle and the resin is too close, the diffusion effect cannot be obtained and the color unevenness is not suppressed. Conversely, if the difference is too large, the diffusion increases and the color unevenness is suppressed, but the light extraction effect is reduced. become.

  It is preferable that the content rate of the particle | grains in the composition Y is 3 to 50 weight% as a ratio of the particle | grains in the sum total of particle | grains and a monomer total amount.

  Examples of the solvent that can be contained in the composition Y include methyl ethyl ketone, ethyl acetate, butyl acetate, cyclohexane, and cyclohexanone. However, for the convenience of forming the cured layer, it is preferable that the composition Y is prepared without adding a solvent and does not require a treatment for volatilizing the solvent during curing.

The preparation method of the composition Y is not specifically limited, For example, it can obtain by mixing the said component.
Although the property of the composition Y is not specifically limited, It is preferable that the viscosity is a range suitable for operations, such as liquid feeding, application | coating, hardening after application | coating. Specifically, the lower limit of the viscosity is preferably 5 cP or more, and more preferably 30 cP or more. On the other hand, the upper limit of the viscosity is preferably 500 cP or less, and more preferably 100 cP or less.

[Method of curing composition Y]
The composition Y is applied on the surface of the easy-adhesion layer to obtain a coating film (a layer of the composition Y in a liquid state). If necessary, the solvent in the layer is volatilized and further subjected to a curing treatment. Thus, the composition Y can be cured to obtain a cured layer.

  The method for applying the composition Y onto the substrate is not particularly limited, and a known application method can be employed. Specific coating methods include wire bar coating, dipping, spraying, spin coating, roll coating, gravure coating, air knife coating, curtain coating, slide coating, and extrusion coating. Can be mentioned. The coating amount of the composition Y is not particularly limited, but can be adjusted so that the thickness of the cured layer obtained after curing becomes a desired thickness.

  The curing treatment can be appropriately performed according to the monomer and polymerization initiator used. In the present invention, since a photopolymerization initiator that is sensitive to visible light or ultraviolet light is used as the polymerization initiator, it can be carried out by irradiation with visible light or ultraviolet light.

  In the curing process, a concavo-convex structure can be provided on the surface of the cured layer opposite to the surface in contact with the easy-adhesion layer by a photopolymer method (2P method). In other words, the mold is placed on the coating, and in that state, the coating Y is irradiated with light through the base material and the easy-adhesion layer to cure the composition Y, and then the mold is peeled off to accurately follow the mold. A hardened layer having a concavo-convex structure with a simple shape can be formed with high efficiency.

  As a mold used for the photopolymer method, a mold having a desired shape can be used. Further, by using a roll having a roll shape, an optical laminate having a long shape can be produced in-line with high efficiency.

[Shape and properties of cured layer]
The hardened layer is preferably made of a material having high hardness from the viewpoint of easily obtaining scratch resistance on the surface. Specifically, when a layer having a film thickness of 7 μm is formed on a substrate without a concavo-convex structure, a material having a pencil hardness of HB or higher is preferable, a material of H or higher is more preferable, and 2H The material which becomes above is more preferable. In particular, when the hardened layer is a light diffusion layer having a concavo-convex structure, a highly durable concavo-convex structure can be easily formed by employing such a material having high hardness.
It is preferable that the surface hardness of the hardened layer that is actually used as the optical layered body of the present invention, such as forming a concavo-convex structure on the surface, is not less than a predetermined high hardness. Specifically, the ΔHz evaluation value in the steel wool test is preferably a predetermined value or less. Specifically, the value of ΔHz is preferably 25 or less, and more preferably 15 or less.

Here, the steel wool test uses a surface property tester (HEIDON-14D, manufactured by Asahi Glass Works), and steel wool (BONSTAR # 0000) is applied to the surface of the hardened layer side of the optical laminate at a weight of 200 g / cm2. The haze value of the optical laminate before and after the test was measured with a turbidimeter (NDM 2000, manufactured by Nippon Denshoku Co., Ltd.), and ΔHz was calculated by the following formula. Do by calculating.
ΔHz = (haze value after SW test) − (haze value before SW test)

  The haze of the cured layer can be 0% to 95% depending on the requirements for the film. When the haze of the hardened layer is 0% to 20%, both the extraction efficiency and the front luminance can be increased. When the haze of the cured layer is 75% to 95%, both the light extraction efficiency and the change in color depending on the observation angle can be reduced. The haze can be adjusted, for example, by appropriately adjusting the content ratio of the particles described above.

The hardened layer preferably has a concavo-convex structure provided on the surface opposite to the surface in contact with the easy adhesion layer. By having such a concavo-convex structure, good extraction efficiency can be achieved when the optical laminate of the present invention is used as a member provided on a light extraction surface of an optical device such as a display device or a light source device. Such an uneven structure can be formed, for example, by the photopolymer method described above.
Specifically, the concavo-convex structure can preferably include a concavo-convex structure including a plurality of concave portions including slopes and flat portions located around the concave portions. Here, the “slope” is a surface that forms an angle that is not parallel to the surface direction of the substrate. On the other hand, the surface on the flat portion can be a surface parallel to the surface direction of the substrate.

  FIG. 1 is a perspective view schematically showing an example of an optical laminate of the present invention provided with a cured layer having a concavo-convex structure layer, and FIG. 2 is a plane passing through the optical laminate shown in FIG. 1 along line 1a-1b. It is sectional drawing which shows the cross section cut | disconnected by. The optical laminate 100 shown in FIG. 1 has a structure in which a base film 121, an easy-adhesion layer 101, and a cured layer 111 are laminated in this order, and the surface 10U of the cured layer 111 is around the recess 113 and the recess 113. It has a concavo-convex structure consisting of a flat portion 114 located in the area.

  Such a concavo-convex structure will be described in more detail with reference to FIGS. FIG. 3 is a partial top view schematically showing the structure of the surface 10U of the hardened layer 111 in an enlarged manner. FIG. 4 is a partial cross-sectional view showing a cross section of the cured layer 111 taken along a plane that passes through the line 10a of FIG. 3 and is perpendicular to the main surface of the optical layered body.

  Each of the plurality of recesses 113 is a depression having a regular quadrangular pyramid shape. Therefore, the slopes 11A to 11D of the recess 113 have the same shape, and the bases 11E to 11H form a square. The line 10a is a line that passes over all the vertices 11P of the recesses 113 in a row, and is a line parallel to the bottom sides 11E and 11G of the recesses 113.

  The recess 113 is continuously arranged in two orthogonal arrangement directions at a constant interval. One of the two arrangement directions X is parallel to the bases 11E and 11G. In this direction X, the plurality of recesses 113 are aligned at a constant interval 11J. The other direction Y of the two arrangement directions is parallel to 11F and 11H. In this direction Y, the plurality of recesses 113 are aligned at a constant interval 11K.

  The angles formed by the inclined surfaces 11A to 11D constituting each of the concave portions 113 and the flat portion 114 (for the inclined surfaces 11B and 11D, the angles 11L and 11M shown in FIG. 4 respectively) are set to 60 °, for example. The apex angle of the regular quadrangular pyramid that is formed, that is, the angle formed by the opposing inclined surfaces at the apex 11P (the angle 11N shown in FIG. 4 for the angles formed by the inclined surfaces 11B and 11D) is also 60 °.

  Thus, when the hardened layer of the optical laminate has a configuration including a plurality of concave portions and a flat portion positioned around each concave portion, such a surface becomes a surface corresponding to the device light exit surface of the surface light source device. In addition, the light extraction efficiency can be increased, the change in color depending on the viewing angle can be reduced, and the occurrence of chipping of the uneven structure due to external impact can be prevented, which in turn improves the mechanical strength of the light exit surface of the device. Can be made.

  When the optical layered body of the present invention includes a cured layer having the above-described concavo-convex structure, displacement of at least one of the x-coordinate and y-coordinate of the chromaticity coordinate in all hemispherical directions in the light emitted from the cured layer side. This can be reduced compared to the case where the above configuration is not adopted. For this reason, in the surface light source device of this invention, when an optical laminated body is provided with the hardened layer which has a concavo-convex structure, the change of the color by an observation angle can be suppressed. As a method of measuring the displacement of chromaticity in all hemispherical directions, for example, the spectral radiance on the normal direction of the device light exit surface (that is, the direction perpendicular to the device light exit surface macroscopically ignoring the concave portion). When a meter is installed and the normal direction is set to 0 °, a chromaticity coordinate can be calculated from the emission spectrum measured in each direction by providing a mechanism that can rotate the light exit surface of the device from -90 to 90 °. The displacement can be calculated.

  When the concavo-convex structure is observed from the direction perpendicular to the optical layered body, the ratio of the area occupied by the flat portion to the total of the area occupied by the flat portion and the area occupied by the concave portion (hereinafter referred to as “flat portion ratio”). The light extraction efficiency of the surface light source device can be improved by appropriately adjusting. Specifically, by setting the flat portion ratio to 10 to 75%, good light extraction efficiency can be obtained, and the mechanical strength of the device light exit surface can be increased.

  In the concavo-convex structure, the concave portion may have, for example, a cone shape, a partial spherical shape, a groove shape, and a combination thereof in addition to the pyramid shape described above. The pyramid shape may be a quadrangular pyramid having a square bottom surface as exemplified by the recess 113, but is not limited thereto, and may be a pyramid shape such as a triangular pyramid, a pentagonal pyramid, a hexagonal pyramid, or a quadrangular pyramid having a non-square base. You can also. Furthermore, the cones and pyramids mentioned in this application include not only ordinary cones and pyramids with sharp points, but also rounded tips or flat chamfered shapes (frustum-shaped shapes, etc.). Yes.

  The depth of the concave portion in the concavo-convex structure is not particularly limited, but the maximum centerline average roughness measured on the surface on which the concavo-convex structure is formed in various directions (various directions in a plane parallel to the light exit surface). The value (Ra (max)) can be in the range of 1 to 50 μm. Moreover, the preferable depth of a recessed part can be defined relatively with respect to the thickness of a hardened layer. For example, when a hard material advantageous for maintaining the durability of the uneven structure is used as the material of the hardened layer, it is possible to increase the flexibility of the optical laminate by reducing the thickness of the hardened layer. Handling of the optical laminate in the manufacturing process of the surface light source device is facilitated. Specifically, the ratio of the thickness 16E of the hardened layer 111 to the depth 16D of the recess shown in FIG. 4 is preferably 1: 1 to 1: 3.

  The lower limit of the thickness of the cured layer is preferably 1 μm or more, more preferably 5 μm or more, while the upper limit thereof is preferably 50 μm or less, more preferably 25 μm or less, and 15 μm or less. Even more preferably. In particular, when the thickness is equal to or less than the above upper limit, it is possible to prevent deformation such as curling of the optical laminate due to curing shrinkage, and to obtain a laminate having a good shape.

  In the present invention, the angle formed by the inclined surface of the recess and the light exit surface is preferably 40 to 70 °, and more preferably 45 to 60 °. For example, when the shape of the recess is a quadrangular pyramid shown in FIG. 10, the apex angle (corner 11 </ b> P in FIG. 4) is preferably 60 to 90 °. Further, from the viewpoint of improving light extraction efficiency while minimizing the change in color depending on the observation angle, it is preferable that the angle formed by the inclined surface and the surface of the base material is large, and specifically, for example, 55 ° or more. Is preferable, and it is still more preferable to set it as 60 degrees or more. In this case, the upper limit of the angle can be about 70 ° in consideration of maintaining the durability of the cured layer.

  In the concavo-convex structure, the plurality of concave portions can be arranged in any manner. For example, a plurality of recesses can be arranged along two or more directions on the surface. More specifically, they can be arranged along two orthogonal directions like the recesses 113 shown in FIGS.

  In the case where the concave portions are arranged in two or more directions, a gap between adjacent concave portions is provided in one or more directions among them, and the flat portion can be constituted by the gap. For example, in the arrangement of the recesses 113 shown in FIG. 3, gaps with intervals 11J and 11K are provided in two orthogonal directions, respectively, and the flat part 114 is configured by the gaps. By adopting such a configuration, it is possible to achieve both good light extraction efficiency and mechanical strength of the laminate surface.

[Other components]
The optical laminated body of this invention can be equipped with arbitrary layers other than the said base material, an easily bonding layer, and a hardened layer as needed. For example, an inorganic barrier layer can be provided on the surface of the substrate opposite to the surface on which the cured layer and the easy adhesion layer are provided. Further, as other optional layers, an antistatic layer, a hard coat layer, a conductivity imparting layer, and a contamination preventing layer can be provided. These arbitrary layers can be provided by a method such as a method of applying and curing the material of the arbitrary layer on the substrate, or a method of applying by thermocompression bonding.

[Inorganic barrier layer]
The inorganic barrier layer that the optical layered body of the present invention can optionally include is an inorganic material as a main component, a component existing in the outside air such as moisture and oxygen, and the internal configuration of a device such as a display device and a light emitting device It is a layer having an ability to barrier a component that can deteriorate an element (for example, a light emitting layer of an organic EL element).
The upper limit of the water vapor permeability of the inorganic barrier layer is preferably 1.0 g / m 2 · day or less, and more preferably 0.2 g / m 2 · day or less. On the other hand, the lower limit of the water vapor transmission rate is most preferably 0 g / m 2 · day, but even a value higher than that can function preferably within the range below the upper limit.

  The material of the inorganic barrier layer is not particularly limited, but preferable materials include silicon oxide, nitride, nitride oxide, aluminum oxide, nitride, nitride oxide, DLC (diamond-like carbon), and 2 of these. The above can be a mixed material. In terms of transparency, silicon oxides and nitride oxides are particularly preferred, while DLC is particularly preferred in terms of affinity with the alicyclic structure-containing polymer resin that is the material of the substrate.

  Examples of silicon oxides, nitrides, and nitride oxides include SiOx (preferably 1.4 <x <2.0 for achieving both transparency and water vapor barrier properties), and SiNy (transparency, water vapor). In order to achieve both barrier properties, 0.5 <y <1.5 is preferable.), SiOxNy (When importance is attached to improving adhesion, oxygen is defined as 1 <x <2.0, 0 <y <1.0. A rich film is preferable, and when importance is placed on improving the water vapor barrier property, a nitrogen-rich film is preferable with 0 <x <0.8 and 0.8 <y <1.3. be able to. Examples of the aluminum oxide, nitride, and nitride oxide include AlOx, AiNy, and AlOxNy. From the viewpoint of inorganic barrier properties, SiOxNy, AlOx, and mixtures thereof can be used as more preferable materials. Carbon may be introduced into these oxides, nitrides, and nitride oxides. When carbon is introduced, the durability of the film during bending can be improved.

  The thickness of the inorganic barrier layer is preferably 5 to 2000 nm, more preferably 20 to 4000 nm. By setting the thickness within this range, good barrier performance can be exhibited without impairing the optical performance of the optical laminate.

  The method for forming the inorganic barrier layer is not particularly limited, but preferably a film forming method such as vapor deposition, sputtering, ion plating, ion beam assisted vapor deposition, arc discharge plasma vapor deposition, thermal CVD, plasma CVD method, etc. on a substrate. It is preferable to form by. When arc discharge plasma is used, evaporated particles having appropriate energy are generated, and a high-density film can be formed. When an inorganic barrier layer is formed using an organic substance such as HMDSO (hexamethyldisiloxane) using plasma CVD or thermal CVD, carbon can be introduced into the film, so that the durability of the film when bent Can be increased. When an inorganic barrier layer containing a plurality of types of components is formed, these can be vapor deposited or sputtered simultaneously.

In the present invention, the inorganic barrier layer protects the base material itself in addition to barriering the transmission of components such as moisture and oxygen from one surface of the optical laminate to the other surface. Can be prevented from expanding by absorbing water vapor from the outside air, and as a result, the effect of preventing deformation of the apparatus can also be exhibited.
In addition, when the transparent electrode layer is formed on the optical laminate of the present invention as a substrate, outgas is released from the base material under the conditions of the transparent electrode layer forming process such as vapor deposition and sputtering. Therefore, the conditions for forming the transparent electrode layer can be freely selected. As a result, the resistance value of the transparent electrode layer can be reduced, or the transparent electrode layer can be easily manufactured. Can be obtained.
Furthermore, in general, the alicyclic structure-containing polymer resin often has low affinity with other materials, and the inorganic barrier layer has high affinity with both the alicyclic structure-containing polymer resin and other materials. In order to obtain, an inorganic barrier layer is provided between a layer made of an alicyclic structure-containing polymer resin and a layer made of another material, so that an alicyclic structure-containing polymer resin and a layer made of another material The effect that the adhesiveness of the resin becomes good can also be exhibited.

[Surface light source device]
The surface light source device of the present invention is a surface light source device including an organic EL light emitting element, and further includes the optical laminated body of the present invention on the light output surface side of the organic EL light emitting element. Specifically, the optical layered body can be provided in the surface light source device such that the surface on the substrate side is the organic EL light emitting element side and the surface on the cured layer side is the light exit surface of the surface light source device.

[Specific example of surface light source device]
FIG. 5 is a perspective view schematically showing an example of the surface light source device of the present invention including the optical layered body 100 of the present invention including the cured layer 111 having the concavo-convex structure shown in FIGS. 1 and 2. FIG. 6 is a cross-sectional view showing a cross section of the surface light source device 10 shown in FIG. 5 cut along a plane that passes through the line 1a-1b in FIG. 5 and is perpendicular to the surface direction of the substrate.

  The surface light source device 10 is a device having a rectangular flat plate structure. The surface light source device 10 includes an organic EL element substrate 131, a transparent electrode layer 141 provided in contact with one surface 146 of the organic EL element substrate 131, and a light emitting layer 142 provided in contact with the transparent electrode layer 141. And a reflective electrode layer 143 provided in contact with the light emitting layer 142. The transparent electrode layer 141, the light emitting layer 142, and the reflective electrode layer 143 constitute the organic EL element 140. The surface light source device 10 further includes a sealing substrate 151 as an optional component on the surface 145 side of the organic EL element 140 opposite to the device light exit surface.

  The surface light source device 10 further includes an optical layered body 100 provided on the other surface 147 of the organic EL element substrate 131 in direct contact with or via an arbitrary layer (adhesive layer, inorganic barrier layer, etc.) not shown. Prepare. The optical layered body 100 is provided such that the surface on the base 121 side faces the organic EL element substrate 131 side, and therefore faces the organic EL light emitting element 140 side.

  The light from the light emitting layer 142 passes through the transparent electrode layer 141 or is reflected by the reflective electrode layer 143, passes through the light emitting layer 142 and the transparent electrode layer 141, and travels toward the device light exit surface side. Most of the light emitted from the organic EL element 140 passes through the organic EL element substrate 131, the base material 121 of the optical laminate, the easy-adhesion layer 101, and the cured layer 111 in this order, and is emitted from the surface 10U. Therefore, the surface 10 </ b> U of the optical laminate 100 serves as a device light exit surface of the surface light source device 10.

  As described above, the light from the light-emitting layer 142 is transmitted through the optical laminate 100 and emitted, whereby the light extraction efficiency can be improved by the uneven structure of the surface 10U of the optical laminate 100. Further, when a layer such as the concavo-convex structure layer 111 has diffusibility, light is emitted in a state where light is further diffused thereby, and as a result, a change in color of the light-emitting surface due to an observation angle can be suppressed.

  Furthermore, since the optical laminate 100 has a high surface hardness and high adhesion between layers, the durability of the surface light source device 10 having the optical laminate 100 is extremely excellent.

  Moreover, when the optical laminated body 100 has what consists of alicyclic structure containing polymer resin as the base material 121, and when the optical laminated body 100 has an inorganic barrier layer, the light emitting layer in external air, such as water vapor | steam and oxygen, is provided. Since the component to be deteriorated is prevented from reaching the light emitting layer from the device light exit surface side, the device having a long life can be obtained.

[Organic EL element of surface light source device]
As exemplified as the organic EL element 140, the surface light source device of the present invention includes an organic EL element, and the organic EL element includes a transparent electrode layer, an electrode layer facing the transparent electrode layer such as a reflective electrode layer, and the like. The light-emitting layer is provided between these electrode layers and emits light when a voltage is applied from the electrodes.

  In the organic EL element, a layer such as an electrode or a light emitting layer constituting the element is formed on a substrate, a sealing member that covers those layers is further provided, and the layer such as the light emitting layer is sealed with the substrate and the sealing member Generally, it is configured. Usually, the element that emits light from the substrate side here is called a bottom emission type, and the element that emits light from the sealing member side is called a top emission type. Any of these may be sufficient as the surface light source device of this invention.

  In this invention, it does not specifically limit as a light emitting layer which comprises an organic EL element, A well-known thing can be selected suitably. The light-emitting material in the light-emitting layer is not limited to one type, and the light-emitting layer is not limited to one layer, and may be a single layer or a combination of a plurality of layers in order to suit the use as a light source. Thereby, light of white or a color close thereto can be emitted.

  The organic EL device may further include 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 in addition to the light emitting layer between the electrodes. The organic EL element can further include arbitrary components such as a wiring for energizing the electrode and a peripheral structure for sealing the light emitting layer.

  The electrode facing the transparent electrode layer in the optical laminate of the organic EL element is not particularly limited, and a known one can be appropriately selected. Like the organic EL element 140 shown in FIGS. 5 and 6, by using the electrode 143 facing the transparent electrode layer 141 as a reflective electrode, an organic EL element that emits light toward the cured layer 111 can be obtained. Moreover, both electrodes can be transparent electrodes, and further by having a reflecting member at a position farther from the light-emitting surface than the transparent electrode far from the light-emitting surface, it is possible to achieve light output to the light-emitting surface side.

Although it does not specifically limit as a material which comprises an electrode and the layer provided among them, The following can be mentioned as a specific example.
ITO etc. can be mentioned as a material of a transparent electrode.
Examples of the material for the hole injection layer include a starburst aromatic diamine compound.
Examples of the material for the hole transport layer include triphenyldiamine derivatives.
Examples of the host material for the yellow light-emitting layer include triphenyldiamine derivatives, and examples of the dopant material for the yellow light-emitting layer include tetracene derivatives. Examples of the material for the green light emitting layer include pyrazoline derivatives.
Examples of the host material for the blue light emitting layer include anthracene derivatives, and examples of the dopant material for the blue light emitting layer include perylene derivatives.
As a material for the red light emitting layer, a europium complex or the like can be used.
Examples of the material for the electron transport layer include an aluminum quinoline complex (Alq). Examples of the cathode material include lithium fluoride and aluminum, which are sequentially stacked by vacuum film formation.

  By appropriately combining the above or other light-emitting layers, a light-emitting layer that generates a light emission color having a complementary color relationship, which is referred to as a stacked type or a tandem type, can be obtained. The combination of complementary colors can be yellow / blue, green / blue / red, or the like.

[Application of surface light source device]
The surface light source device of the present invention having the optical laminate of the present invention can be used for use as a light source device such as a lighting fixture and a backlight device.
The luminaire includes the surface light source device of the present invention as a light source, and can further include arbitrary components such as a member for holding the light source and a circuit for supplying power. The backlight device includes the surface light source device of the present invention as a light source, and further includes a housing, a circuit for supplying electric power, a diffusion plate for making light emitted more uniform, a diffusion sheet, a prism sheet, and the like. The components can be included. The use of the backlight device can be used as a backlight of a display device such as a liquid crystal display device that displays an image by controlling pixels and a display device that displays a fixed image such as a signboard.

[Others]
The present invention is not limited to the above specific examples, and can be arbitrarily modified within the scope of the claims of the present application and equivalents thereof.
For example, the optical layered body of the present invention may further include an arbitrary layer in addition to the above-described layers. Such an arbitrary layer may be, for example, a coating layer further provided on the concavo-convex structure on the surface of the cured layer, and the coating layer defines the concavo-convex structure on the device light exit surface of the surface light source device of the present invention. It may be a thing.
Moreover, in the illustration of the above embodiment, the concave portions distributed over the entire surface of the light diffusing layer are shown as those having only the same shape distributed, but in the concave-convex structure, concave portions having different shapes are mixed. You may do it. For example, pyramid-shaped recesses of different sizes are mixed, pyramid-shaped recesses and cone-shaped recesses are mixed, or a combination of multiple pyramids and a simple pyramid shape are mixed. It may be.
Further, in the above specific example, the width of the flat portion constituting the concavo-convex structure and the interval between the adjacent flat portions are always constant, but the width of the flat portion is narrow and wide. Moreover, the location where the space | interval of a flat part is narrow and the wide location may be mixed. In such a manner, rainbow unevenness due to interference is suppressed by adopting an aspect in which one or more elements of the height, width, and interval of the flat portion are provided with a dimensional difference exceeding the difference that causes interference of emitted light. can do.
Moreover, although the surface light source device 10 of the said specific example had the board | substrate 131 for organic EL elements, and the base material 121 for optical laminated bodies, the surface light source device of this invention is not restricted to such an aspect. For example, the organic EL element substrate 131 may be omitted, and the base material 121 for the optical laminate may also serve as the organic EL element substrate, and the organic EL element 140 may be formed directly on this surface.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In the following examples, “parts” and “%” representing the quantity ratio of materials represent weight ratios unless otherwise specified.
<Example 1>
(1-1. Composition X1)
170 parts Superflex 210 (Daiichi Kogyo Seiyaku Co., Ltd .: solid content 35%), 6 parts adipic acid dihydrazide (Wako Pure Chemical Industries), 3 parts Denacol EX-521 (manufactured by Nagase ChemteX), 1800 pure water The mixture consisting of parts was uniformly stirred and mixed, and then filtered through a 3 μm filter to obtain a composition X1 for forming an easy-adhesion layer.

(1-2. Multi-layered product 1 having a base material and an easily adhesive layer)
A ZEONOR film (ZF-14-100, manufactured by Nippon Zeon Co., Ltd.) having a width of 1300 mm and a length of 1000 m was prepared as a substrate. The surface of this substrate was treated with a discharge amount of 500 W · min / m ² using a corona discharge treatment apparatus (manufactured by Kasuga Denki Co., Ltd.). Using a gravure coater on the corona-treated surface of the substrate, the composition X1 was applied so that the dry film thickness was 0.1 μm to form a coating liquid layer, and this layer was dried at 95 ° C. An easy-adhesion layer was formed to obtain a multilayer 1 having a layer structure of (base material)-(easy-adhesion layer).

(1-3. Composition Y1)
2-methacryloyloxyethyl isocyanate (isocyanate group content 6.45 mmol / g, acid value 0.0 mg KOH / g, viscosity 2.6 cP) 3 parts, trimethylolpropane triacrylate (isocyanate group content 0.0 mmol / g, acid) 50 parts by weight 0.1 mg KOH / g, viscosity 100 cP), 47 parts ethoxylated phenyl acrylate (isocyanate group content 0.0 mmol / g, acid value 1.0 mg KOH / g, viscosity 20 cP), photopolymerization initiator (Irgacure 907) An absorption coefficient of 4.665 × 102 (ml / g · cm in MeOH), a melting point of 70 to 75 ° C., manufactured by Ciba Specialty Chemicals Co., Ltd.) was uniformly stirred and mixed, and then filtered through a 3 μm filter. A composition Y1 for forming a cured layer was obtained.
In the obtained composition Y1, the isocyanate group content in the total amount of monomers was 0.19 mmol / g, and the acid value was 0.52 mgKOH / g.

(1-4. Optical laminated body 1)
A composition Y1 was applied to the surface of the multilayer body 1 on the easy adhesion layer side with a coating film thickness of 15 μm using a die coater. After coating, the polyethylene terephthalate film (Luminer U34, manufactured by Toray Industries, Inc., hereinafter referred to as PET) is laminated on the surface without leaving it, and from the base material side of the multilayer 1 using a D valve (manufactured by Fusion), It hardened | cured by irradiating an ultraviolet-ray with the integrated light quantity 800mJ / cm2, and obtained the optical laminated body 1 which has a layer structure of (base material)-(adhesion bonding layer)-(hardening layer)-(PET).

(1-5. Evaluation)
The obtained optical laminated body 1 was cut out to a size of 100 mm × 100 mm, used as a sample, and the substrate adhesion was evaluated. Evaluation of adhesion is carried out by peeling and peeling a 10 mm × 100 mm sample at a speed of 20 mm / min and an angle of 90 degrees with a tensile test device (load measuring device LTS-50N-S100 manufactured by Minebea Co., Ltd.). did. As a result, it was confirmed that the substrate was broken and there was no peeling in the cured layer and the easy-adhesion layer, and it was found that the adhesion was good.

<Example 2>
Example 1 except that the photopolymerization initiator was changed to LUCIRIN TPO (absorption coefficient 4.720 × 10 ² (ml / g · cm in MeOH), melting point 87 to 93 ° C., manufactured by Ciba Specialty Chemicals) Thus, an optical layered body 2 having a layer structure of (base material)-(adhesive layer)-(cured layer)-(PET) was obtained. As a result of evaluating and confirming the adhesiveness of the obtained optical layered body 2 in the same manner as in Example 1, it was confirmed that there was no peeling and the adhesiveness was good.

<Example 3>
Example 1 except that the photopolymerization initiator was changed to Irgacure OXE1 (absorption coefficient 6.969 × 10 ² (ml / g · cm in MeOH), melting point 40 to 42 ° C., manufactured by Ciba Specialty Chemicals) Similarly, the optical laminated body 3 which has the layer structure of (base material)-(adhesion bonding layer)-(hardening layer)-(PET) was obtained. As a result of evaluating and confirming the adhesion of the obtained optical laminate 3 in the same manner as in Example 1, it was confirmed that there was no peeling, and it was found that the adhesion was good.

<Example 4>
Example 1 except that the photopolymerization initiator was changed to Irgacure 651 (absorption coefficient 3.613 × 10 ² (ml / g · cm in MeOH), melting point 64 to 67 ° C., manufactured by Ciba Specialty Chemicals). Similarly, an optical layered body 4 having a layer structure of (base material)-(adhesive layer)-(cured layer)-(PET) was obtained. As a result of evaluating and confirming the adhesiveness of the obtained optical layered body 4 in the same manner as in Example 1, it was confirmed that there was no peeling and the adhesiveness was good.

<Comparative Example 1>
Example 1 except that the photopolymerization initiator was changed to Irgacure 184 (absorption coefficient 8.864 × 10 (ml / g · cm in MeOH), melting point 45 to 49 ° C., manufactured by Ciba Specialty Chemicals) Thus, an optical laminate 5 having a layer structure of (base material)-(adhesive layer)-(cured layer)-(PET) was obtained. As a result of evaluating and confirming the adhesiveness of the obtained optical laminate 5 in the same manner as in Example 1, it was found that there was peeling in the cured layer and the easy-adhesive layer, and the adhesiveness was poor.
Furthermore, after applying the composition Y1 with a coating film thickness of 15 μm to the surface of the multilayer 5 in the comparative example 5 on the easy-adhesion layer side, after leaving it for 2 minutes, the PET was laminated. When the optical layered product was produced by irradiating with ultraviolet rays, it was found that there was no peeling, but the working efficiency was significantly reduced.

<Comparative example 2>
Example 1 except that the photopolymerization initiator was changed to Irgacure 754 (absorption coefficient 5.900 × 10 (ml / g · cm in MeOH), melting point −22 ° C. or less, manufactured by Ciba Specialty Chemicals) Thus, an optical layered body 6 having a layer structure of (base material)-(adhesive layer)-(cured layer)-(PET) was obtained. As a result of evaluating and confirming the adhesion of the obtained optical laminate 6 in the same manner as in Example 1, it was found that there was peeling in the cured layer and the easy-adhesion layer, and the adhesion was poor.

<Comparative Example 3>
The photopolymerization initiator was changed to Irgacure 819 (absorption coefficient 2.309 × 10 ³ (ml / g · cm in MeOH), melting point 127 to 133 ° C., manufactured by Ciba Specialty Chemicals) to obtain composition Y7 However, the solubility was poor and it could not be cured.

From the above results, in the 365 nm wavelength band, a wavelength of 365 nm as compared with Examples 1 to 4 using a photopolymerization initiator having an extinction coefficient of 2.0 × 10 ² (ml / g · cm in MeOH) or more. In Comparative Examples 1 and 2 using a photopolymerization initiator having an extinction coefficient of less than 2.0 × 10 ² (ml / g · cm in MeOH) in the belt, adhesion is remarkably low or working efficiency is poor. I understand.

<Example 8>
(Optical laminate 8)
A cylindrical transfer roll having a diameter of 300 mm and a length of 400 mm was prepared. This transfer roll has a shape in which a regular quadrangular pyramid having an apex angle of 60 ° and a base of 25 μm is arranged in two directions orthogonal to each other at a pitch of 30 μm (that is, a flat portion having a width of 5 μm exists between adjacent quadrangular pyramids). Had.
A composition Y1 was applied to the surface of the multilayer body 1 on the easy adhesion layer side with a coating film thickness of 15 μm using a die coater. The coated surface was pressed against the transfer roll, and the multilayer 1 was nipped with a rubber roll having a diameter of 100 mm. The composition is obtained by irradiating with ultraviolet light with an integrated light quantity of 1500 mJ / cm 2 from the base material side of the multilayer object 1 at a position where the multilayer object 1 is pressed against the transfer roll, using a D valve (manufactured by Fusion). The coating film of Y1 was cured in a state where the shape on the transfer roll was transferred to obtain an optical laminate 1 having a layer structure of (base material)-(adhesive layer)-(cured layer having an uneven structure). . Similar to the optical laminate 100 shown in FIGS. 1 and 2, the optical laminate 1 has a concavo-convex structure including a plurality of recesses and a flat portion located around each recess on the surface on the cured layer side. It was. The shape of the recess was a quadrangular pyramid-shaped depression, its base was a 25 μm square, the apex angle was 60 °, and the width of the flat portion between adjacent quadrangular pyramids was 5 μm.

(Organic electroluminescence element)
A transparent electrode layer 100 nm, a hole transport layer 10 nm, a yellow light emitting layer 20 nm, a blue light emitting layer 15 nm, an electron transport layer 15 nm, an electron injection layer 1 nm on one main surface of a 0.7 mm thick glass substrate (refractive index 1.53). And a reflective electrode layer of 100 nm were formed in this order. The hole transport layer to the electron transport layer were all made of an organic material. The yellow light emitting layer and the blue light emitting layer have different emission spectra.
The material forming each layer from the transparent electrode layer to the reflective electrode layer is as follows: Transparent electrode layer; tin-added indium oxide (ITO)
Hole transport layer; 4,4′-bis [N- (naphthyl) -N-phenylamino] biphenyl (α-NPD)
・ Yellow light emitting layer: 1.5% by weight of rubrene added α-NPD
Blue light-emitting layer; iridium complex added at 10% by weight 4,4′-dicarbazolyl-1,1′-biphenyl (CBP)
-Electron transport layer; phenanthroline derivative (BCP)
-Electron injection layer; lithium fluoride (LiF)
-Reflective electrode layer: Al

The transparent electrode layer was formed by a reactive sputtering method using an ITO target, and the surface resistance was 10Ω / □ or less. In addition, the formation from the hole injection layer to the reflective electrode layer is carried out by placing a glass substrate on which a transparent electrode layer has already been formed in a vacuum evaporation apparatus, and successively using the resistance heating method for the materials from the hole transport layer to the reflective electrode layer. This was done by vapor deposition. The system internal pressure was 5 × 10 −3 Pa and the evaporation rate was 0.1 to 0.2 nm / s.
Further, wiring for energization was attached to the electrode layer, and the hole transport layer to the reflective electrode layer were sealed with a sealing member to produce an organic electroluminescence light emitting device. The obtained organic electroluminescence light-emitting element had a rectangular light-emitting surface capable of emitting white light from the glass substrate side.

(Adhesive for optical laminate adhesive)
Acrylic copolymer (AT-352, solid content concentration 35.7 wt%, made by Seiden Chemical Co.) 100 parts by weight, curing agent (tolylene diisocyanate) 0.2 parts, epoxy (A-375, made by Seiden Chemical Co.) 0 .2 parts, 1 part of silane coupling agent (S-1, manufactured by Seiden Chemical Co., Ltd.), 10 parts of silicone resin (Tospearl 120, 2.0 μm, manufactured by Momentive Materials), 30 parts of ethyl acetate It stirred uniformly and the adhesive solution was produced.

(Optical laminate with adhesive layer)
The surface of the optical laminate 8 on the substrate side was subjected to corona treatment at a discharge amount of 500 W · min / m 2 using a corona discharge treatment apparatus (manufactured by Kasuga Electric Co., Ltd.). On the corona-treated surface, the pressure-sensitive adhesive solution obtained in (15-1) above was applied using a gravure coater so that the dry film thickness was 30 μm, and dried at 85 ° C. to form a pressure-sensitive adhesive layer. An optical laminate with an adhesive layer (having a layer structure of (adhesive layer)-(base material)-(adhesive layer)-(cured layer having an uneven structure)) was obtained.

(Surface light source device)
The surface having the optical layered body of the present invention is bonded to the light emitting surface of the organic electroluminescence light-emitting element, that is, the surface on the glass substrate side, with the adhesive layer-attached optical laminate being in contact with the glass substrate. A light source device was obtained.

DESCRIPTION OF SYMBOLS 10: Surface light source device 10U: Surface of laminated body for surface light source devices 11A to 11D: Slope 11E to 11H: Bottom of concave part 100: Optical laminated body 101: Easy adhesion layer 111: Hardened layer having concavo-convex structure 113: Concave part 114: Flat part 121: Optical laminate base material 131: Organic EL element substrate 140: Organic EL element 141: Transparent electrode layer 142: Light emitting layer 143: Reflective electrode layer 144: Transparent electrode layer 151: Sealing substrate

Claims (8)

An optical laminate comprising a base material, an easy-adhesion layer provided on the surface of the base material, and a cured layer provided in direct contact with the easy-adhesion layer,
The easy adhesion layer is a layer formed of the composition X containing a urethane resin,
The cured layer is a layer formed by curing a composition Y containing monomer A, monomer B and a photopolymerization initiator,
The monomer A is a monomer containing one or more isocyanate groups per molecule and one or more polymerizable unsaturated groups per molecule,
The monomer B is a monomer having 3 or more polymerizable unsaturated groups per molecule and not containing an isocyanate group,
The optical polymerization initiator is a photopolymerization initiator having a melting point of 100 ° C. or lower and having an extinction coefficient of 2.0 × 10 ² (ml / g · cm in MeOH) or more in a 365 nm wavelength band. body. The optical laminate according to claim 1,
In the composition Y, an optical layered body in which the content ratio of isocyanate groups in the total amount of monomers is 0.25 mmol / g or more, and the ratio of the monomer B in the total amount of monomers is 15% by weight or more. In the optical laminated body according to claim 1 or 2,
The hardened layer is an optical laminate having a concavo-convex structure provided on a surface opposite to a surface in contact with the easy-adhesion layer. In the optical laminated body according to claim 3,
The cured layer is
Applying the composition Y on the easy-adhesion layer to obtain a coating film,
With the mold applied to the coating film, the composition Y is cured by irradiating the coating film with light through the base material and the easy-adhesion layer,
An optical laminate obtained by peeling the mold. In the optical layered product according to any one of claims 1 to 4,
The hardened layer is an optical laminate containing particles. In the optical layered product according to any one of claims 1 to 5,
The easy adhesion layer is an optical laminate containing silica particles. In the optical layered product according to any one of claims 1 to 6,
The composition X is an optical laminate including the urethane resin as a water-based urethane resin. A surface light source device comprising an organic electroluminescence light emitting element,
The surface light source device further equipped with the optical laminated body of any one of Claims 1-7 in the light emission surface side rather than the said organic electroluminescent light emitting element.

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