JP4633503B2 - Optical laminate - Google Patents

Description

  The present invention relates to an optical laminate that prevents interface reflection and interference fringes.

  An image display surface in an image display device such as a liquid crystal display (LCD) or a cathode ray tube display device (CRT) is required to reduce reflection due to light rays emitted from an external light source and to improve its visibility. On the other hand, by using an optical laminate (for example, an antireflection laminate) in which an antiglare layer or an antireflection layer is formed on a light transmissive substrate, reflection of the image display surface of the image display device can be achieved. It is common to reduce and improve visibility.

  However, in an optical laminated body in which layers having a large difference in refractive index are laminated, it has often been observed that interface reflection and interference fringes occur at the interface between the layers that overlap each other. In particular, when black is reproduced on the image display surface of the screen display device, it is often pointed out that interference fringes are conspicuously generated, and as a result, the visibility of the image is lowered and the appearance of the image display surface is impaired. It was. In particular, when the refractive index of the light-transmitting substrate is different from the refractive index of the hard coat layer, interference fringes are likely to occur.

  On the other hand, in Unexamined-Japanese-Patent No. 2003-75605 (patent document 1), on a transparent base film, a medium refractive index layer whose refractive index is 1.5-1.7, and refractive index are 1.6-1. By using an antireflection hard coat sheet in which a high refractive index layer of .8 and a low refractive index layer made of a refractive index material lower than the high refractive index layer are laminated in this order from the transparent substrate film side, interfacial reflection is achieved. In addition, it has been proposed that interference fringes and the like can be eliminated. This prior art can be said to have been made by paying attention to the material itself constituting each layer. Japanese Patent Laid-Open No. 2003-205563 (Patent Document 2) proposes a method of forming a hard coat layer on a base material using a resin containing a solvent that dissolves the base material.

However, the present inventors have confirmed that when a hard coat layer is formed on a polyethylene terephthalate base material, a polyethylene terephthalate base material and a hard coat are formed by interposing an adhesive layer comprising a specific composition. There has not yet been proposed that the interface state with the layer can be improved and the reflection interface and interference fringes can be effectively prevented.
JP 2003-75605 A JP 2003-205563 A

  In the present invention, when the hard coat layer is formed on the polyethylene terephthalate base material, the present inventors intervene an adhesive layer containing a specific composition, thereby preventing interfacial reflection and interference fringes. The knowledge that generation | occurrence | production can be prevented effectively was acquired. Accordingly, an object of the present invention is to provide an optical laminate that effectively prevents the occurrence of interface reflection and interference fringes at the interface between the polyethylene terephthalate substrate and the hard coat layer, and has improved mechanical strength and visibility. Is.

Therefore, the optical laminate according to the present invention is
A polyethylene terephthalate base material is provided with a hard coat layer via an adhesive layer,
The adhesive layer is formed of a resin and a dispersion;
The dispersion is a metal oxide fine particle having a primary particle diameter in the range of 1 to 30 nm, an ionizing radiation curable resin, a dispersant having an anionic polar group, an organic solvent, a titanate-based or aluminum-based one. And a coupling agent.

Optical laminate
Adhesive layer The adhesive layer is formed of a composition comprising a resin and a dispersion. The mixing ratio of the resin and the dispersion can be determined as appropriate, but is preferably 75:25 or more and 92: 8 or less. Moreover, the preferable refractive index of the whole contact bonding layer is 1.67 or more and 1.69 or less, and the film thickness of an contact bonding layer becomes like this. Preferably it is 50 to 150 nm.

1) As the resin resin, one having a refractive index of 1.50 or more and 1.53 or less when it is dried and cured is preferably used. As a specific example of the resin, a polyester resin or a urethane resin is preferably a main resin.

  Specific examples of the polyester resin include terephthalic acid, isophthalic acid, phthalic acid, methylphthalic acid, trimellitic acid, pyromellitic acid, adipic acid, sebacic acid, succinic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid. Acid raw materials such as acid, hexahydrophthalic acid and their reactive derivatives, ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol 1,4-cyclohexanedimethanol, neopentyl glycol, isopentyl glycol, bishydroxyethyl terephthalate, hydrogenated bisphenol A, hydrogenated bisphenol AA alkylene oxide adduct, trimethylolethane, Trimethylolpropane, glycerol, pentaerythritol, which was prepared in a manner well known from the alcohol feedstock such as 2,2,4-trimethylpentane-1,3-diol is not particularly limited. The most preferable polyester resin is an amorphous copolymer polyester.

  As a specific example of the urethane-based resin, it is preferable to use, for example, a reaction-curable urethane-based adhesive such as a moisture curable type (one-component type) or a thermosetting type (two-component type). That is, in the moisture curable type, a polyisocyanate compound oligomer and prepolymer, and in the thermosetting type, a polyisocyanate compound monomer, oligomer and prepolymer, and a polyol compound oligomer and prepolymer can be mixed and used. When these reaction-curing urethane adhesives are used, an aging treatment is performed after lamination at a temperature of room temperature to 40 ° C.

Other Components According to a preferred embodiment of the present invention, it is preferable to add a compound having an isocyanate group to the composition for an adhesive layer. Specific examples of the compound having an isocyanate group include tolylene diisocyanate (TDI), 3,3′-tolylene-4,4′-isocyanate, diphenylmethane 4,4′-diisocyanate (MDI), and triphenylmethane p, p ′. , P "-triisocyanate (TM), 2,4-tolylene dimer (TT), naphthalene-1,5-diisocyanate, tris (4-phenylisocyanate) thiophosphate, crude (MDI), TDI trimer , Dicyclohexamethane 4,4′-diisocyanate (HMDI), hydrogenated TDI (HTDI), metaxylylene diisocyanate (XDI), hexahydrometaxylylene diisocyanate (HXDI), hexamethylene diisocyanate, trimethylpropane-1-methyl 2-isocyano 4-carbabamate, polymethylene polyphenyl isocyanate, 3,3′-dimethoxy 4,4′-diphenyl diisocyanate, diphenyl ether 2,4,1′-triisocyanate, m-xylylene diisocyanate (MXDI), polymethylene polyphenyl isocyanate ( PAPI) etc. The addition amount of the compound having an isocyanate group is preferably 10% by weight or more based on the total amount of the composition for the adhesive layer.

Other resins may be added to the composition for the adhesive layer used in the present invention, and examples thereof include ionizing radiation curable resins. The addition of an ionizing radiation curable resin is preferable because the adhesion and flexibility of the hard coat layer laminated on the adhesive layer can be freely adjusted.
Among the ionizing radiation curable resins, those having an acrylate functional group are preferable. For example, relatively low molecular weight polyester resins, polyether resins, acrylic resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, (meth) acrylates of polyfunctional compounds such as polyhydric alcohols Monofunctional monomers such as oligomers or prepolymers such as ethyl (meth) acrylate, ethylhexyl (meth) acrylate, styrene, methylstyrene, N-vinylpyrrolidone as reactive diluents and polyfunctional monomers such as trimethylolpropane tri ( (Meth) acrylate, hexanediol (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate Rate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate may be preferably mentioned.

  In order to convert the ionizing radiation curable resin into an ultraviolet curable resin, acetophenones, benzophenones, Michler benzoylbenzoate, α-amyloxime ester, tetramethylthiuram monosulfide, thioxanthone, etc. As a photosensitizer, n-butylamine, triethylamine, tri-n-butylphosphine and the like can be mixed and used. In particular, in the present invention, it is preferable to mix urethane acrylate as an oligomer and dipentaerythritol hexaacrylate as a monomer.

2) The dispersion is composed of metal oxide fine particles having a primary particle diameter in the range of 1 to 30 nm, ionizing radiation curable resin, a dispersant having an anionic polar group, an organic solvent, a titanate or aluminum. And a coupling agent of the system. The dispersion is preferably prepared such that the refractive index when dried and cured is 1.72 or more and 1.80 or less.

Metal oxide fine particles Metal oxide fine particles have a high refractive index of medium refractive index to high refractive index (1.90 to 2.55) and are colorless or non-colored, and any shape is possible. It may be. The primary particle diameter of the metal oxide fine particles in the present invention is 1 to 30 nm. Those having a thickness of 30 nm or less are preferably used. The primary particle diameter of the metal oxide fine particles may be visually measured with a scanning electron microscope (SEM), a transmission electron microscope (TEM), or the like, or a dynamic light scattering method or a static light scattering method is used. Mechanical measurement may be performed by a particle size distribution meter or the like.

  Specific examples of the metal oxide fine particles include one or two selected from the group consisting of titanium oxide, zirconium oxide, zinc oxide, tin oxide, cerium oxide, antimony oxide, indium tin mixed oxide and antimony tin mixed oxide. The above mixture is mentioned, Preferably titanium oxide is mentioned. Specific examples of titanium oxide include rutile type, anatase type, and amorphous type. Preferably, rutile type titanium oxide having a high refractive index can be preferably used.

Specific examples of the ionizing radiation-curable resin ionizing radiation curable resin, a monomer having an ionizing radiation directly by irradiation, or by the action of the initiator indirectly the functional groups which occur polymerization reaction such as ultraviolet light or electron beam Or an oligomer is mentioned. In the present invention, a radically polymerizable monomer or oligomer having an ethylenic double bond can be mainly used, and a photoinitiator may be combined as necessary. Also, other ionizing radiation curable resins can be used. For example, a photocationically polymerizable monomer or oligomer such as an epoxy group-containing compound may be used. A photocationic polymerization initiator is used in combination with the photocationic polymerizable resin as necessary. The monomer or oligomer that is a resin is preferably a polyfunctional resin having two or more polymerizable functional groups so that cross-linking occurs between the molecules of the resin.

  Specific examples of radically polymerizable monomers and oligomers having an ethylenic double bond include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, hydroxybutyl acrylate, 2-hydroxy-3-phenoxy. Monofunctional (meth) acrylates such as cypropyl acrylate, carboxypolycaprolactone acrylate, acrylic acid, methacrylic acid, acrylamide; diacrylates such as pentaerythritol triacrylate, ethylene glycol diacrylate, pentaerythritol diacrylate monostearate; trimethylolpropane Tri (meth) acrylates such as triacrylate and pentaerythritol triacrylate; pentaerythritol tetraacrylate derivative or dipe Polyfunctional (meth) acrylates such as data erythritol pentaacrylate, or can include these radical polymerizable monomers are polymerized oligomer. In the present specification, “(meth) acrylate” means acrylate and / or methacrylate.

  Among the ionizing radiation curable resins, it is preferable to use a resin in which a hydroxyl group is left in the molecule. Since the hydroxyl group is also an anionic polar group, this resin has high affinity with the metal oxide fine particles and acts as a dispersion aid. Therefore, by using this resin, the dispersibility of the metal oxide fine particles in the dispersion is improved, and the amount of the dispersant used is reduced. Since the dispersant does not have a function as a resin, the coating strength can be improved by reducing the blending ratio of the dispersant.

  Specific examples of the resin in which a hydroxyl group is left in the molecule include those in which pentaerythritol polyfunctional (meth) acrylate or dipentaerythritol polyfunctional (meth) acrylate is used as a binder resin skeleton, and the hydroxyl group is left in the molecule. It is done. In such a resin, two or more molecules of (meth) acrylic acid are ester-bonded to one molecule of pentaerythritol or dipentaerythritol, but some of the hydroxyl groups inherent in the pentaerythritol or dipentaerythritol molecule are For example, pentaerythritol triacrylate can be exemplified. Since pentaerythritol polyfunctional acrylate and dipentaerythritol polyfunctional acrylate have two or more ethylenic double bonds in one molecule, a crosslinking reaction occurs during polymerization, and high coating strength can be obtained.

Examples of photoinitiators for initiating photoinitiator radical polymerization include 1-hydroxy-cyclohexyl-phenyl-ketone, 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one , Benzyldimethylketone, 1- (4-dodecylphenyl) -2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- (4-isopropyl Phenyl) -2-hydroxy-2-methylpropan-1-one, benzophenone, and the like, among which 1-hydroxy-cyclohexyl-phenyl-ketone and 2-methyl-1 [4- (methylthio) phenyl] -2-Morpholinopropan-1-one initiates and accelerates the polymerization reaction by irradiation with ionizing radiation even in a small amount In, it is preferably used in the present invention. These can be used alone or in combination of two or more. These are also present in commercial products, for example, 1-hydroxy-cyclohexyl-phenyl-ketone is available from Ciba Geigy Japan under the trade name Irgacure 184.

The dispersant having an anionic polar group has an anionic polar group having a high affinity for the metal oxide fine particles, particularly the titanium oxide fine particles, and is dispersible for the metal oxide fine particles. Is added to give Examples of the anionic polar group include a carboxyl group, a phosphate group, and a hydroxyl group. As the dispersant having an anionic polar group, specifically, a product group supplied by Big Chemie Japan under the trade name of Dispersic, namely Disperbyk-111, Disperbyk-110, Disperbyk-116, Disperbyk- 140, Disperbyk-161, Disperbyk-162, Disperbyk-163, Disperbyk-164, Disperbyk-170, Disperbyk-171, Disperbyk-174, Disperbyk-180, and Disperbyk-180.

  Among these, the main chain having an ethylene oxide chain skeleton has a molecular structure in which a side chain comprising an anionic polar group as described above or a side chain having an anionic polar group is bonded, and the number average It is preferable to use a compound having a molecular weight of 2,000 to 20,000 because particularly good dispersibility is obtained. The number average molecular weight can be measured by a GPC (gel permeation chromatography) method. In the above Dispersic series, Dispersic 163 (Disperbyk-163) is mentioned as one that meets such conditions.

Organic solvent An organic solvent is used to dissolve / disperse solid components in a dispersion, for example, alcohols such as isopropyl alcohol, methanol and ethanol; ketones such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; ethyl acetate and acetic acid Esters such as butyl; halogenated hydrocarbons; aromatic hydrocarbons such as toluene and xylene; or a mixture thereof can be used.

  In the present invention, it is preferable to use a ketone-based organic solvent. As a ketone solvent, it contains a single solvent composed of one kind of ketone, a mixed solvent composed of two or more kinds of ketones, and other solvents together with one or more kinds of ketones, and has lost its properties as a ketone solvent. Those that are not can be used. Preferably, a ketone solvent in which 70% by weight or more, particularly 80% by weight or more of the solvent is occupied by one or two or more ketones is used.

Coupling agent Use of titanate-based or aluminum-based coupling agent improves the dispersibility of the metal oxide fine particles and decreases the viscosity of the coating composition, improves the workability, increases the filling of the metal oxide fine particles, and increases the interfacial voids. It has the effect of reducing (decrease in agglomerates).

  Examples of the titanate or aluminum coupling agent include a carboxyl type, a pyrophosphate type, a phosphite type, and an amino type, which have a property of shifting from hydrophobic to hydrophilic in this order.

  Specific examples of titanate coupling agents include those having a hydrophilic group containing Ti that interacts with metal oxide fine particles and a hydrophobic group that interacts with a resin or solvent matrix. For example, Ajinomoto Co., Inc. Product group (KR-TTS, KR-46B, KR-55, KR-41B, KR-38S, KR-138S, KR-238S, 338X, KR- 44, KR9SA). For example, in the case of alkyl titanates, those having a long alkyl chain, those forming a stable complex, and polymers having a high molecular weight are desirable.

  Specific examples of the aluminum coupling agent include aluminum isopropylate, monosec-butoxyaluminum diisopropylate, aluminum sec-butyrate, aluminum ethylate, ethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate), alkyl Examples include acetoacetate aluminum diisopropylate, aluminum monoacetylacetonate bis (ethylacetoacetate), aluminum tris (acetylacetonate), aluminum = monoisopropoxymonooroxyethylacetoacetate, and cyclic aluminum oxide isopropylate.

The other component dispersion contains, in addition to the above essential components, a polymerization initiator of an ionizing radiation curable resin as necessary, but may further contain other components. For example, an ultraviolet shielding agent, an ultraviolet absorber, a surface conditioner (leveling agent), or the like can be used as necessary.

Preparation Method of Dispersion The metal oxide fine particles are preferably 30 to 65% by weight based on the total solid content. The coupling agent is desirably contained in an amount of 1 to 15% by weight, more preferably 3 to 10% by weight, based on the total solid content. The dispersion is preferably blended with an organic solvent in a proportion of 50 to 99.5 parts by weight with respect to 0.5 to 50 parts by weight of the total solid content. The dispersant is desirably 10 to 20% by weight based on the total solid content. The resin is desirably 20 to 60% by weight based on the total solid content.

  The dispersion is obtained by mixing essential components and other components in an arbitrary order, adding a medium such as beads to the resulting mixture, and appropriately dispersing the mixture with a paint shaker or bead mill. It is done. More specifically, it may be adjusted by the method disclosed in JP-A-2003-96400. Therefore, the contents of the specification and drawings disclosed in this publication form the contents of this specification.

Light transmissive substrate The optical laminate according to the present invention uses a polyethylene terephthalate substrate (refractive index of 1.60 to 1.65) as the light transmissive substrate.

The hard coat layer “hard coat layer” refers to a layer having a hardness of “H” or higher in a pencil hardness test defined by JIS 5600-5-4 (1999). The thickness of the hard coat layer (during curing) is in the range of 0.1 to 100 μm, preferably 0.8 to 20 μm. The hard coat layer is formed of a resin and an optional component. In order to impart flexibility to the hard coat layer, it is preferable to add an oligomer or polymer of a dimer or higher.

The resin resin is preferably transparent, and specific examples thereof include an ionizing radiation curable resin that is a resin curable by ultraviolet rays or an electron beam, a mixture of an ionizing radiation curable resin and a solvent-drying resin, or a heat Examples of the curable resin include ionizing radiation curable resins.

  Specific examples of the ionizing radiation curable resin include those having an acrylate functional group, for example, a polyester resin, polyether resin, acrylic resin, epoxy resin, urethane resin, alkyd resin, spiroacetal resin, polybutadiene having a relatively low molecular weight. Resins, polythiol polyene resins, oligomers or prepolymers such as (meth) allylates of polyfunctional compounds such as polyhydric alcohols, and reactive diluents, and specific examples thereof include ethyl (meth) acrylate, ethylhexyl (meta ) Monofunctional monomers such as acrylate, styrene, methylstyrene, N-vinylpyrrolidone and polyfunctional monomers such as polymethylolpropane tri (meth) acrylate, hexanediol (meth) acrylate, tripropylene glycol di (meth) Acrylate, diethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, etc. .

  When using an ionizing radiation curable resin as an ultraviolet curable resin, it is preferable to use a photopolymerization initiator. Specific examples of the photopolymerization initiator include acetophenones, benzophenones, Michler benzoylbenzoate, α-amyloxime ester, tetramethylchuram monosulfide, and thioxanthones. Further, it is preferable to use a mixture of photosensitizers, and specific examples thereof include n-butylamine, triethylamine, poly-n-butylphosphine and the like.

  The solvent-drying resin used by mixing with the ionizing radiation curable resin mainly includes a thermoplastic resin. As the thermoplastic resin, those generally exemplified are used. By adding the solvent-drying resin, coating film defects on the coated surface can be effectively prevented. According to a preferred embodiment of the present invention, when the material of the transparent substrate is a cellulose resin such as TAC, as a preferred specific example of the thermoplastic resin, a cellulose resin such as nitrocellulose, acetylcellulose, cellulose acetate propionate, Examples thereof include ethyl hydroxyethyl cellulose.

  Specific examples of the thermosetting resin include phenol resin, urea resin, diallyl phthalate resin, melanin resin, guanamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin, aminoalkyd resin, melamine-urea cocondensation resin, silicon resin. And polysiloxane resin. When a thermosetting resin is used, a curing agent such as a crosslinking agent and a polymerization initiator, a polymerization accelerator, a solvent, a viscosity modifier and the like can be further added as necessary.

Antistatic Agent and / or Antiglare Agent The hard coat layer according to the present invention preferably comprises an antistatic agent and / or an antiglare agent. The antistatic agent may be the same as that described in the section of the antistatic layer described later, and the antiglare agent may be the same as described in the section of the antiglare layer described later.

In order to form the solvent hard coat layer, a hard coat layer composition in which the above components are mixed with a solvent is used. Specific examples of the solvent include alcohols such as isopropyl alcohol, methanol and ethanol; ketones such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; esters such as acetone, methyl acetate, ethyl acetate and butyl acetate; halogenated hydrocarbons; Aromatic hydrocarbons such as toluene and xylene; or a mixture thereof, preferably ketones.

Other Layers The optical layered body according to the present invention is basically composed of a light-transmitting substrate, a thin layer formed thereon, and a hard coat layer as described above. However, one or two or more layers described below may be formed on the hard coat layer in consideration of the function or application as an optical laminate.
Antistatic layer The antistatic layer comprises an antistatic agent and a resin. The mixing weight ratio of the antistatic agent and the resin is 90:10 or more and 10:90 or less, preferably 75:25 or more and 50:50 or less.

Antistatic agent (conductive agent)
Specific examples of the antistatic agent that forms the antistatic layer include quaternary ammonium salts, pyridinium salts, various cationic compounds having a cationic group such as first to third amino groups, sulfonate groups, and sulfate esters. Anionic compounds having anionic groups such as bases, phosphate ester bases, phosphonate bases, amphoteric compounds such as amino acids and aminosulfate esters, nonionic compounds such as amino alcohols, glycerols, and polyethylene glycols, tin And organic metal compounds such as titanium alkoxides and metal chelate compounds such as acetylacetonate salts thereof, and compounds obtained by increasing the molecular weight of the compounds listed above. Coupling having a tertiary amino group, a quaternary ammonium group, or a metal chelate moiety, and a monomer or oligomer polymerizable by ionizing radiation, or a polymerizable functional group polymerizable by ionizing radiation Polymerizable compounds such as organometallic compounds such as agents can also be used as antistatic agents.

Moreover, electroconductive ultrafine particles are mentioned. Specific examples of the conductive fine particles include those made of a metal oxide. Examples of such metal oxides include ZnO (refractive index 1.90, the numerical value in parentheses below represents the refractive index), CeO ₂ (1.95), Sb ₂ O ₂ (1.71), SnO. ₂ (1.997), indium tin oxide (1.95) often referred to as ITO, In ₂ O ₃ (2.00), Al ₂ O ₃ (1.63), antimony-doped tin oxide (abbreviation) ATO, 2.0), aluminum-doped zinc oxide (abbreviation: AZO, 2.0), and the like. The fine particles refer to those having a so-called submicron size of 1 micron or less, and preferably those having an average particle size of 0.1 nm to 0.1 μm.

As specific examples of the resin resin, a thermoplastic resin, a thermosetting resin, an ionizing radiation curable resin, or an ionizing radiation curable compound (including an organic reactive silicon compound) can be used. As the resin, a thermoplastic resin can also be used, but it is more preferable to use a thermosetting resin, and more preferable is an ionizing radiation curable composition containing an ionizing radiation curable resin or an ionizing radiation curable compound. It is.

  The ionizing radiation curable composition is a mixture of a polymerizable unsaturated bond or a prepolymer, an oligomer, and / or a monomer having an epoxy group in a molecule. Here, the ionizing radiation refers to an electromagnetic wave or a charged particle beam having an energy quantum capable of polymerizing or crosslinking molecules, and usually an ultraviolet ray or an electron beam is used.

  Examples of prepolymers and oligomers in ionizing radiation curable compositions include unsaturated polyesters such as unsaturated dicarboxylic acid and polyhydric alcohol condensates, and methacrylates such as polyester methacrylate, polyether methacrylate, polyol methacrylate, and melamine methacrylate. Acrylates such as polyester acrylate, epoxy acrylate, urethane acrylate, polyether acrylate, polyol acrylate, and melamine acrylate, and cationic polymerization type epoxy compounds.

  Examples of the monomer in the ionizing radiation curable composition include styrene monomers such as styrene and α-methylstyrene, methyl acrylate, 2-ethylhexyl acrylate, methoxyethyl acrylate, butoxyethyl acrylate, and butyl acrylate. Acrylic esters such as methoxybutyl acrylate and phenyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, methoxyethyl methacrylate, ethoxymethyl methacrylate, phenyl methacrylate, lauryl methacrylate, etc. , 2- (N, N-diethylamino) ethyl acrylate, 2- (N, N-dimethylamino) ethyl acrylate, 2- (N, N-dibenzylamino) methyl acrylate, acrylic acid- 2- (N, N-diethyla B) Unsaturated substituted amino alcohol esters such as propyl, unsaturated carboxylic acid amides such as acrylamide and methacrylamide, ethylene glycol diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, 1,6-hexanediol di Compounds such as acrylate, triethylene glycol diacrylate, polyfunctional compounds such as dipropylene glycol diacrylate, ethylene glycol diacrylate, propylene glycol dimethacrylate, diethylene glycol dimethacrylate, and / or two or more thiol groups in the molecule Polythiol compounds having, for example, trimethylolpropane trithioglycolate, trimethylolpropane trithiopropylate, pentaerythritol tet And lathioglycolate.

  Usually, as the monomer in the ionizing radiation curable composition, the above compounds are used alone or in combination of two or more as required, but in order to give ordinary application suitability to the ionizing radiation curable composition. Further, the prepolymer or oligomer is preferably 5% by weight or more, and the monomer and / or polythiol compound is preferably 95% by weight or less.

  When flexibility is required when an ionizing radiation curable composition is applied and cured, it is preferable to reduce the amount of monomer or use an acrylate monomer having 1 or 2 functional groups. When wear resistance, heat resistance, and solvent resistance are required when an ionizing radiation curable composition is applied and cured, ionizing radiation curing such as using an acrylate monomer with three or more functional groups It is possible to design a sex composition. Here, 2-hydroxy acrylate, 2-hexyl acrylate, and phenoxyethyl acrylate are exemplified as those having one functional group. Examples of those having 2 functional groups include ethylene glycol diacrylate and 1,6-hexanediol diacrylate. Examples of the functional group having 3 or more include trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate.

  In order to adjust physical properties such as flexibility and surface hardness when an ionizing radiation curable composition is applied and cured, a resin that is not cured by ionizing radiation irradiation can be added to the ionizing radiation curable composition. . Specific examples of the resin include the following. Thermoplastic resins such as polyurethane resin, cellulose resin, polyvinyl butyral resin, polyester resin, acrylic resin, polyvinyl chloride resin, and polyvinyl acetate. Among these, addition of a polyurethane resin, a cellulose resin, a polyvinyl butyral resin, or the like is preferable from the viewpoint of improving flexibility.

  When hardening after application | coating of an ionizing radiation curable composition is performed by ultraviolet irradiation, a photoinitiator and a photoinitiator are added. As the photopolymerization initiator, in the case of a resin system having a radical polymerizable unsaturated group, acetophenones, benzophenones, thioxanthones, benzoin, benzoin methyl ether and the like are used alone or in combination. In the case of a resin system having a cationic polymerizable functional group, an aromatic diazonium salt, an aromatic sulfonium salt, an aromatic iodonium salt, a metatheron compound, a benzoin sulfonic acid ester or the like is used alone or as a mixture as a photopolymerization initiator. . The addition amount of a photoinitiator is 0.1-10 weight part with respect to 100 weight part of ionizing radiation-curable compositions.

In the ionizing radiation curable composition, the following organic reactive silicon compound may be used in combination.
1 of the organosilicon compound can be represented by the general formula R _m Si (OR ′) _n , R and R ′ represent an alkyl group having 1 to 10 carbon atoms, a subscript m of R and a subscript n of OR ′ Each is an integer satisfying the relationship m + n = 4.

  Specifically, tetramethoxysilane, tetraethoxysilane, tetra-iso-propoxysilane, tetra-n-propoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, tetra-tert-butoxysilane, tetrapenta Ethoxysilane, tetrapenta-iso-propoxysilane, tetrapenta-n-propoxysilane, tetrapenta-n-butoxysilane, tetrapenta-sec-butoxysilane, tetrapenta-tert-butoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltri Butoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethylethoxysilane, dimethylmethoxysilane, dimethylpropoxysilane, dimethylbutoxysilane, methyl Silane, methyl diethoxy silane, hexyl trimethoxy silane and the like.

  The organosilicon compound that can be used in combination with the ionizing radiation curable composition is a silane coupling agent. Specifically, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ- Aminopropyltriethoxysilane, γ-methacryloxypropylmethoxysilane, N-β- (N-vinylbenzylaminoethyl) -γ-aminopropylmethoxysilane / hydrochloride, γ-glycidoxypropyltrimethoxysilane, aminosilane, methyl Methoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, hexamethyldisilazane, vinyltris (β-methoxyethoxy) silane, octadecyldimethyl [3- (trimethoxysilyl) propyl ] Ammonium chloride, methyltrichlorosilane, dimethyldichlorosilane and the like.

  The thickness of the antistatic layer is preferably about 30 nm to 1 μm.

Antiglare layer The antiglare layer comprises an antiglare agent and a resin. The thickness of the antiglare layer is preferably about 1 μm to 10 μm. The solvent and the resin may be the same as described for the hard coat layer.

Antiglare The antiglare agent particles Preferably, inorganic, may be of any organic system. The fine particles exhibit anti-glare properties and are preferably transparent. Specific examples of the fine particles include silica beads in the case of inorganic systems, and plastic beads in the case of organic systems, and more preferably those having transparency. Specific examples of plastic beads include styrene beads (refractive index 1.59), melamine beads (refractive index 1.57), acrylic beads (refractive index 1.49), acrylic-styrene beads (refractive index 1.54), Examples thereof include polycarbonate beads and polyethylene beads. According to a preferred embodiment of the present invention, plastic beads having a hydrophobic group on the surface thereof are preferably used, and for example, styrene beads are preferably used.

Low Refractive Index Layer The low refractive index layer is composed of a resin containing silica or magnesium fluoride, a fluorine resin that is a low refractive index resin, silica, or a fluorine resin containing magnesium fluoride, and has a refractive index of It can be composed of a thin film of 1.46 or less, also about 30 nm to 1 μm, or a thin film of silica or magnesium fluoride by chemical vapor deposition or physical vapor deposition. The resin other than the fluororesin is the same as the resin used for constituting the antistatic layer.

  More preferably, the low refractive index layer can be composed of a silicone-containing vinylidene fluoride copolymer. Specifically, this silicone-containing vinylidene fluoride copolymer is a monomer containing 30 to 90% vinylidene fluoride and 5 to 50% hexafluoropropylene (including percentages below, all in terms of mass). It is obtained by copolymerization using the composition as a raw material, and comprises 100 parts of a fluorine-containing copolymer having a fluorine content of 60 to 70% and 80 to 150 parts of a polymerizable compound having an ethylenically unsaturated group. A low refractive index having a refractive index of less than 1.60 (preferably 1.46 or less) which is a thin film having a film thickness of 200 nm or less and is provided with scratch resistance by using this resin composition. Form a layer.

  In the silicone-containing vinylidene fluoride copolymer constituting the low refractive index layer, the proportion of each component in the monomer composition is such that the vinylidene fluoride is 30 to 90%, preferably 40 to 80%, particularly preferably 40 to 40%. 70% and hexafluoropropylene is 5 to 50%, preferably 10 to 50%, particularly preferably 15 to 45%. This monomer composition may further contain 0 to 40%, preferably 0 to 35%, particularly preferably 10 to 30% of tetrafluoroethylene.

  In the above monomer composition, other copolymer components are, for example, in the range of 20% or less, preferably in the range of 10% or less, within the range in which the intended purpose and effect of the silicone-containing vinylidene fluoride copolymer are not impaired. Specific examples of such other copolymerization components are fluoroethylene, trifluoroethylene, chlorotrifluoroethylene, 1,2-dichloro-1,2-difluoroethylene, 2-bromo-3,3,3-trifluoroethylene, 3-bromo-3,3-difluoropropylene, 3,3,3-trifluoropropylene, 1,1,2-trichloro-3,3,3-tri Examples thereof include polymerizable monomers having fluorine atoms such as fluoropropylene and α-trifluoromethacrylic acid.

  The fluorine-containing copolymer obtained from the monomer composition as described above needs to have a fluorine content of 60 to 70%, preferably a fluorine content of 62 to 70%, particularly preferably 64 to 68. %. When the fluorine content is in such a specific range, the fluorine-containing polymer has good solubility in a solvent, and contains such a fluorine-containing polymer as a component. Since it has excellent adhesion to various substrates, it forms a thin film with high transparency and low refractive index and sufficiently excellent mechanical strength, so the scratch resistance of the surface on which the thin film is formed The mechanical properties such as the above can be made sufficiently high, which is extremely suitable.

  The fluorine-containing copolymer preferably has a molecular weight of 5,000 to 200,000, particularly 10,000 to 100,000 in terms of polystyrene-equivalent number average molecular weight. By using a fluorine-containing copolymer having such a molecular weight, the viscosity of the resulting fluorine-based resin composition becomes a suitable size, and therefore surely has a suitable coating property. It can be. The fluorine-containing copolymer preferably has a refractive index of 1.45 or less, particularly 1.42 or less, more preferably 1.40 or less. When a fluorine-containing copolymer having a refractive index exceeding 1.45 is used, a thin film formed from the obtained fluorine-based paint may have a small antireflection effect.

In addition, the low refractive index layer also can be formed of a thin film made of SiO _2, an evaporation method, a sputtering method, or a plasma CVD method or the like, or to form a SiO ₂ gel film from the sol solution containing SiO ₂ sol It may be formed by a method. The low refractive index layer, in addition to SiO ₂ also, the or a thin film MgF _2, but may be configured in other materials, in terms of high adhesion to the lower layer, it is preferable to use a SiO ₂ thin film. Among the above methods, when the plasma CVD method is used, it is preferable to use organosiloxane as a raw material gas under the condition that there is no other inorganic vapor deposition source, and to maintain the deposition target as low as possible. It is preferable.

  According to a preferred embodiment of the present invention, it is preferable to use “fine particles having voids”. The “fine particles having voids” can reduce the refractive index while maintaining the layer strength of the low refractive index layer. In the present invention, the term “fine particles having voids” refers to a structure in which a gas is filled with gas and / or a porous structure containing gas, and the gas in the fine particle is compared with the original refractive index of the fine particle. It means fine particles whose refractive index decreases in inverse proportion to the occupation ratio. The present invention also includes fine particles capable of forming a nanoporous structure inside and / or at least part of the surface depending on the form, structure, aggregation state, and dispersion state of the fine particles inside the coating film. It is.

  As specific examples of the inorganic fine particles having voids, silica fine particles prepared by using the technique disclosed in Japanese Patent Application Laid-Open No. 2001-233611 are preferably exemplified. Since silica fine particles having voids are easy to manufacture and have high hardness, when a low refractive index layer is formed by mixing with a binder, the layer strength is improved and the refractive index is 1.20-1. It is possible to prepare within the range of about 45. In particular, as specific examples of the organic fine particles having voids, hollow polymer fine particles prepared by using the technique disclosed in JP-A-2002-80503 are preferably exemplified.

  The fine particles capable of forming a nanoporous structure inside and / or at least part of the surface of the coating film are manufactured for the purpose of increasing the specific surface area in addition to the silica fine particles, and the packing column and the surface porosity Examples include controlled release materials that adsorb various chemical substances in the mass part, porous fine particles used for catalyst fixation, or dispersions and aggregates of hollow fine particles intended to be incorporated into heat insulating materials and low dielectric materials. it can. As such a specific example, an aggregate of porous silica fine particles and a silica fine particle manufactured by Nissan Chemical Industries, Ltd. were linked in a chain form from the product names Nippon and Nippon manufactured by Nippon Silica Kogyo Co., Ltd. as commercial products. From the colloidal silica UP series (trade name) having a structure, those within the range of the preferable particle diameter of the present invention can be used.

  The average particle size of the fine particles is 5 nm or more and 300 nm or less, preferably the lower limit is 8 nm or more and the upper limit is 100 nm or less, more preferably the lower limit is 10 nm or more and the upper limit is 80 nm or less. When the average particle diameter of the fine particles is within this range, excellent transparency can be imparted to the low refractive index layer.

Method for producing optical laminate
Adjustment of Liquid Composition Each liquid composition for the antistatic layer, thin layer, hard coat layer and the like may be adjusted by mixing and dispersing the components described above according to a general preparation method. For mixing and dispersing, it is possible to appropriately disperse with a paint shaker or a bead mill.

Specific examples of the coating method of each liquid composition on the surface of the coating light transmissive substrate and the surface of the antistatic layer include spin coating, dipping, spraying, die coating, bar coating, roll coater, Various methods such as a meniscus coater method, a flexographic printing method, a screen printing method, and a speed coater method can be used.

Use of optical laminate The optical laminate according to the present invention is used as a hard coat laminate, preferably as an antireflection laminate. The optical laminate according to the present invention is used for a transmissive display device. In particular, it is used for display displays of televisions, computers, word processors and the like. In particular, it is used on the surface of displays such as CRTs and liquid crystal panels.

Example 1
Preparation of composition for adhesive layer 1) Byron 280 (manufactured by Toyobo) as a resin composition resin
As solvent, toluene and methyl ethyl ketone: methyl ethyl ketone (1: 1)
2) Composition of the dispersion
Rutile type titanium oxide: MT-01 (manufactured by Teica) 10 parts by weight Dispersant 2 parts by weight Disperbic 163 (manufactured by Big Chemie Japan)
Photocurable resin: PET30 (Nippon Kayaku) 4 parts by weight Titanate coupling agent: TA-25 (manufactured by Matsumoto Kosho) 1.28 parts by weight Photoinitiator: Irgacure 184 0.2 parts by weight (manufactured by Ciba Geigy Japan)
Methyl isobutyl ketone 17.48 parts by weight

Preparation of composition for hard coat layer A hard coat resin prepared by mixing DPHA, acrylic polymer and Irgacure 184 at 80: 20: 6 was diluted with toluene.

Preparation of optical laminate
The mixture shown in the preparation of the adhesive layer composition was mixed to prepare the adhesive layer composition, diluted with a solvent in which toluene and methyl ethyl ketone were 1: 1, and then a polyethylene terephthalate base material having a film thickness of 100 nm by gravure coating. (188 μm: “PET A4100”: manufactured by Toyobo Co., Ltd.) was coated on one side and dried at 70 ° C. for 1 minute. Thereafter, the hard coat layer composition was applied on the adhesive layer with a gravure coater to a thickness of 6 μm, dried at 70 ° C. for 1 minute, cured by 136 mj UV irradiation, and then adhered to the PET substrate with the adhesive layer and the hard layer. A coat layer was provided. The adhesive layer produced at this time had a refractive index of 1.57, and no interference fringes were generated.

Example 2
In Example 1, 1) The resin of the composition of the adhesive layer resin was changed to LX660 and KW75 (4: 3) [Dainippon Ink Co., Ltd.], which are two-component thermosetting urethane adhesives, and are shown in Table 1. An optical laminate was obtained in the same manner except that the blending ratio and the coating film thickness were changed to 50 nm. In addition, since the composition for contact bonding layers needs thermosetting, it aged at 40 degreeC for 4 days. The refractive index of the adhesive layer produced at this time was 1.59, and no interference fringes were generated.

Example 3
In Example 1, 1) Two-component thermosetting urethane adhesive and polyester resin LX660 (manufactured by Dainippon Ink), KW75 (manufactured by Dainippon Ink) and Byron 300 are used. (Toyobo Co., Ltd.) (10: 1: 1) The optical laminate was obtained in the same manner except that the blending ratio shown in Table 1 and the film thickness were changed to 150 nm. The adhesive layer produced at this time had a refractive index of 1.58 and was a good optical laminate with no interference fringes. Since the adhesive layer composition needs to be thermally cured, it was subjected to an aging treatment at 40 ° C. for 4 days.

Comparative Example 1
The adhesive layer of Example 1 was not provided, and the product was changed to a commercially available PET base material (188 μm: A4300 [manufactured by Toyobo Co., Ltd.]) that had already been subjected to double-sided easy adhesion treatment (refractive index 1.56). In the same manner as above, an optical laminate having a hard coat layer formed was obtained. In this optical laminate, strong interference fringes were generated.

Evaluation Tests The following evaluation tests were performed on the optical laminates of Examples and Comparative Examples, and the results are shown in Table 1.

Evaluation 1: Strength (Hardness) Evaluation Pencil hardness was used for the hardness of the optical laminate. As a measuring method, it measured based on JIS-K-5400 and was the following reference | standard.
Evaluation standard evaluation A: There was a strength of 3H or more.
Evaluation x: The strength was less than H.

Evaluation 2: Adhesion evaluation test According to JIS-K-5400 (cross-cut adhesion test method), the presence or absence of peeling of the coating film on the outermost surface of the optical laminate was visually observed and evaluated according to the following criteria.
Evaluation Criteria Evaluation A: There was no peeling of the coating film.
Evaluation (circle): Although it was not all the coating films, peeling existed.
Evaluation x: All of the coating film was peeled off.

Evaluation 3: Interference fringe presence / absence test A black tape was applied to the surface opposite to the hard coat layer of the optical laminate to prevent back reflection, and the optical laminate was visually observed from the surface of the hard coat layer. Evaluated.
Evaluation criteria Evaluation A: No interference fringes were generated.
Evaluation ○: Some interference fringes were observed, but there was no problem as a product.
Evaluation x: Interference fringes were generated.

Table 1
Composition for adhesive layer Evaluation 1 Evaluation 2 Evaluation 3
Resin: Dispersion
Example 1 88:12 ◎ ◎ ○
Example 2 84:16 ◎ ◎ ○
Example 3 75:25 ◎ ◎ ◎
Comparative Example 1-◎ ◎ ×

Claims (6)

An optical laminate used for an image display surface in an image display device,
On the polyethylene terephthalate base material, a hard coat layer is provided via an adhesive layer,
The adhesive layer is formed of a polyester resin and a two-component thermosetting urethane adhesive and a dispersion,
The dispersion is a metal oxide fine particle having a primary particle diameter of 1 nm to 30 nm and a refractive index of 1.90 to 2.55, a radical polymerizable monomer or oligomer having an ethylenic double bond, an anionic property A dispersant having a polar group, an organic solvent, and a titanate or aluminum coupling agent,
The metal oxide fine particles are selected from the group consisting of titanium oxide or titanium oxide, zirconium oxide, zinc oxide, tin oxide, cerium oxide, antimony oxide, indium tin mixed oxide and antimony tin mixed oxide. The optical laminated body which is 1 type which becomes or a mixture of 2 or more types. The optical laminate according to claim 1, wherein a mixing ratio of the polyester resin and the two-component thermosetting urethane adhesive and the dispersion is 75:25 or more and 92: 8 or less.   The optical laminated body according to claim 1 or 2, wherein the adhesive layer further comprises a compound having an isocyanate group.   The optical laminate according to any one of claims 1 to 3, wherein the hard coat layer comprises an antistatic agent and / or an antiglare agent.   The optical laminate according to any one of claims 1 to 4, wherein an antistatic layer, an antiglare layer, a low refractive index layer, or two or more of these layers are formed on the hard coat layer. body.   The optical laminate according to any one of claims 1 to 5, wherein the optical laminate is an antireflection laminate.