JP5056021B2 - Optical laminate - Google Patents

Description

The present invention relates to an optical laminate.

In an image display device such as a cathode ray tube display (CRT), a liquid crystal display (LCD), a plasma display (PDP), an electroluminescence display (ELD), etc., the outermost surface generally has antireflection properties, hardware properties, transparency, etc. Optical laminates having various functions are provided. As the base material for these functional layers, an acrylic resin having excellent transparency and hardness is used. However, the base material of such a functional layer is easily charged due to its high insulating properties, and dirt due to adhesion of dust or the like is generated, and there are obstacles due to charging in the display manufacturing process as well as in use. There was a problem that occurred.

In order to prevent such charging, an antistatic layer containing a conductive antistatic agent has been conventionally provided on a part of the optical laminate (see, for example, Patent Document 1). As the antistatic agent, known antistatic agents such as quaternary ammonium salts and inorganic conductive ultrafine particles have been used.

In recent years, the use of organic conductive materials instead of various antistatic agents as antistatic agents has begun to be studied. The organic conductive material has attracted attention as a good conductive material having permanent conductivity and excellent transparency. The organic conductive material is classified into two types: an electron conduction type in which electrons move via carriers such as solitons and polarons, and an ion conduction type in which ions themselves move in the system. Examples of the electron conductive organic conductive material include polyacetylene, polyaniline, and polythiophene. However, these electron conductive organic conductive materials have a problem that the antistatic performance is not stable due to humidity and temperature.

On the other hand, as an ion conductive type organic conductive material, an optical element composition using a lithium ion conductive antistatic agent such as lithium perfluoroalkyl sulfonate, lithium bisperfluoroalkyl sulfonimide, or lithium perchlorate. It is disclosed (for example, see Patent Document 2). However, when a composition containing such a lithium ion conduction type antistatic agent is applied using a coater such as a gravure coater, rust may be generated on the metal part of the coater.

JP 2006-126808 A JP 200531282 A

SUMMARY OF THE INVENTION In view of the above situation, the present invention aims to provide an optical laminate that maintains transparency, stably exhibits antistatic performance, and can suppress rust generation on a coater or the like during production. It is.

The present invention is an optical laminate comprising a hard coat layer on a light transmissive substrate, wherein the hard coat layer contains an organic boron compound, and the organic boron compound comprises a polyether, a poly It is an optical laminate characterized by being an ionic conjugate of aldehyde or polyketone and boron .
The present invention is an optical laminate comprising an antistatic layer and a hard coat layer on a light transmissive substrate, wherein the antistatic layer contains an organic boron compound, It is also an optical laminate characterized in that it is an ionic conjugate of polyether, polyaldehyde or polyketone and boron .
The hard coat layer is formed of a hard coat layer composition containing a resin, a solvent, and an organoboron compound, and the solvent preferably contains a permeable solvent.
The antistatic layer is formed of a composition for an antistatic layer containing a resin, a solvent, and an organic boron compound, and the solvent preferably contains a permeable solvent.
The present invention is also a polarizing plate comprising a polarizing element, wherein the optical laminate of the present invention is provided on the surface of the polarizing element opposite to the surface on which the hard coat layer is present in the optical laminate. It is also a polarizing plate characterized by being made.
The present invention is also an image display device comprising the optical laminate of the present invention or the polarizing plate of the present invention on the outermost surface.
The present invention is described in detail below.

The present invention is an optical laminate comprising an ion conductive type organic boron compound as an antistatic agent. By containing the organoboron compound as an antistatic agent, it has high transparency and can exhibit stable antistatic performance that is not affected by temperature and humidity. Furthermore, the organoboron compound has the advantages of low cost and low toxicity. Similarly, it is preferable because there is an advantage that the occurrence frequency of bleed is low compared to the case of using a lithium ion conduction type antistatic agent which is an ion conduction type.
As the organic boron compound, an ionic conjugate of polyether, polyaldehyde or polyketone and boron is preferable.

The optical layered body of the present invention uses the above organic boron compound as an antistatic agent and has good charging performance. The optical layered body of the present invention is obtained by forming a hard coat layer on a light transmissive substrate (optical layered body 1), and an antistatic layer and a hard coat layer on the light transmissive substrate. Can be mentioned (optical laminate 2).

The optical laminate 1 is an optical laminate obtained by forming a hard coat layer on a light transmissive substrate, and the hard coat layer contains the organoboron compound. Furthermore, the optical layered body 2 is formed by forming an antistatic layer and a hard coat layer on a light-transmitting substrate, and the antistatic layer contains the organoboron compound. .

Hereinafter, the base material and composition used in the present invention will be specifically described. In the present invention, unless otherwise specified, curable resin precursors such as monomers, oligomers, and prepolymers are referred to as “resins”.

(Optical laminate 1)
Hard coat layer The optical laminate 1 is formed by forming a hard coat layer containing the organoboron compound. The “hard coat layer” in the present invention refers to a layer showing a hardness of “H” or higher in a pencil hardness test specified by JIS K5600-5-4 (1999). In the present invention, the hard coat layer preferably has a pencil hardness of 2H or more, and the Vickers hardness is preferably 250 N / mm or more.

The hard coat layer contains an organic boron compound, and the solid content of the organic boron compound is preferably 30 to 70% by mass. If the content is less than 30% by mass, sufficient antistatic performance may not be obtained. If the content exceeds 70% by mass, the coating film strength may decrease, such being undesirable.

Although the said hard-coat layer is not specifically limited as long as it has transparency, It is preferable to contain resin further.
The resin is not particularly limited. For example, an ionizing radiation curable resin that is a resin curable by ultraviolet rays or an electron beam, an ionizing radiation curable resin, and a solvent-drying resin (added to adjust the solid content during coating) The resin may be a mixture of a resin that forms a film only by drying the solvent, or a thermosetting resin, and preferably an ionizing radiation curable resin. Moreover, according to a preferable aspect of the present invention, a resin comprising at least an ionizing radiation curable resin and a thermosetting resin can be used.

Examples of the ionizing radiation curable resin include compounds having one or more unsaturated bonds such as compounds having an acrylate functional group. Examples of the compound having one unsaturated bond include ethyl (meth) acrylate, ethylhexyl (meth) acrylate, styrene, methylstyrene, N-vinylpyrrolidone and the like. Examples of the compound having two or more unsaturated bonds include polymethylolpropane tri (meth) acrylate, hexanediol (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, pentaerythritol tri ( Reaction products such as (meth) allyllate and polyfunctional compounds such as (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate And poly (meth) acrylate esters of polyhydric alcohols). In the present specification, “(meth) acrylate” refers to methacrylate and acrylate.

In addition to the above compounds, relatively low molecular weight polyester resins having unsaturated double bonds, polyether resins, acrylic resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, etc. It can be used as an ionizing radiation curable resin.

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-amino oxime esters, thioxanthones, propiophenones, benzyls, benzoins, and acylphosphine oxides. Further, it is preferable to use a mixture of photosensitizers, and specific examples thereof include n-butylamine, triethylamine, poly-n-butylphosphine and the like.

As the photopolymerization initiator, in the case of a resin system having a radical polymerizable unsaturated group, it is preferable to use acetophenones, benzophenones, thioxanthones, benzoin, benzoin methyl ether or the like 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 metallocene compound, a benzoin sulfonic acid ester or the like is used alone or as a mixture as a photopolymerization initiator. It is preferable. The addition amount of the photopolymerization initiator is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the ionizing radiation curable composition.

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. As a specific example of a preferable 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. Specific examples of preferable thermoplastic resins include, for example, styrene resins, (meth) acrylic resins, vinyl acetate resins, vinyl ether resins, halogen-containing resins, alicyclic olefin resins, polycarbonate resins, and polyester resins. , Polyamide resins, cellulose derivatives, silicone resins, rubbers or elastomers. As the thermoplastic resin, it is usually preferable to use a resin that is non-crystalline and soluble in an organic solvent (particularly a common solvent capable of dissolving a plurality of polymers and curable compounds). In particular, resins with high moldability or film formability, transparency and weather resistance, such as styrene resins, (meth) acrylic resins, alicyclic olefin resins, polyester resins, cellulose derivatives (cellulose esters, etc.) Etc. are preferred.

According to a preferred embodiment of the present invention, when the material of the light-transmitting substrate is a cellulose resin such as triacetyl cellulose “TAC”, as a preferred specific example of the thermoplastic resin, a cellulose resin such as nitrocellulose, acetyl Examples include cellulose, cellulose acetate propionate, and ethyl hydroxyethyl cellulose. By using a cellulose-based resin, it is possible to improve the adhesion and transparency between the light-transmitting substrate and the hard coat layer.

Examples of the thermosetting resin that can be used as the 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, Examples thereof include silicon resins and polysiloxane resins. 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 used in combination as necessary.

The hard coat layer in the optical layered body 1 dissolves or disperses the organic boron compound, the resin and, if necessary, additives (for example, a polymerization initiator, an antiglare agent, an antifouling agent, a leveling agent) in a solvent. The resulting solution or dispersion is used as a composition for a hard coat layer, a coating film is formed from the composition, and the coating film is cured. The solvent can be selected and used according to the type and solubility of the resin, and can dissolve at least solids (a plurality of polymers and curable resin precursors, reaction initiators, other additives) uniformly. If it is. Examples of such solvents include ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), ethers (dioxane, tetrahydrofuran, etc.), aliphatic hydrocarbons (hexane, etc.), alicyclic hydrocarbons ( Cyclohexane, etc.), aromatic hydrocarbons (toluene, xylene, etc.), halogenated carbons (dichloromethane, dichloroethane, etc.), esters (methyl acetate, ethyl acetate, butyl acetate, etc.), water, alcohols (ethanol, isopropanol, Butanol, cyclohexanol, etc.), cellosolves (methyl cellosolve, ethyl cellosolve, etc.), cellosolve acetates, sulfoxides (dimethylsulfoxide, etc.), amides (dimethylformamide, dimethylacetamide, etc.), etc. It may be a mixed solvent.

The hard coat layer composition preferably contains a permeable solvent that is permeable to the light transmissive substrate. In the present invention, the “permeability” of the osmotic solvent is intended to include all concepts such as permeability, swellability and wettability with respect to the light-transmitting substrate. When such a permeable solvent swells and wets the light-transmitting substrate, a part of the hard coat layer composition permeates to the light-transmitting substrate. Thereby, high strength can be obtained. Furthermore, the organoboron compound contained in the hard coat layer composition can be present in a sufficiently dispersed state without agglomerating in the hard coat layer, and excellent antistatic performance can be maintained. .

Furthermore, the said solvent can be determined according to whether resin in a hard-coat layer has adhesiveness with respect to a base material. For example, when the resin has no adhesion to the substrate, it is preferable to use a solvent that has permeability to the substrate. For example, when the base material is TAC, specific examples of the permeable solvent include ketones; acetone, methyl ethyl ketone, cyclohexanone, methyl isobutyl ketone, diacetone alcohol, esters; methyl formate, methyl acetate, ethyl acetate, butyl acetate. , Ethyl lactate, nitrogen-containing compounds; nitromethane, acetonitrile, N-methylpyrrolidone, N, N-dimethylformamide, glycols; methyl glycol, methyl glycol acetate, ethers; tetrahydrofuran, 1,4-dioxane, dioxolane, diisopropyl ether, Halogenated hydrocarbons; methylene chloride, chloroform, tetrachloroethane, glycol ethers; methyl cellosolve, ethyl cellosolve, butyl cellosolve, cellosolve acetate, other dimethyls Sulfoxide, include propylene carbonate, or include mixtures thereof, preferably esters, ketones; methyl acetate, ethyl acetate, butyl acetate, methyl ethyl ketone. In addition, alcohols such as methanol, ethanol, isopropyl alcohol, butanol, and isobutyl alcohol, and aromatic hydrocarbons such as toluene and xylene can be mixed with the permeable solvent.
Moreover, in the composition for hard-coat layers, it is desirable that the permeable solvent is 10 to 100% by mass, particularly 50 to 100% by mass, based on the total amount of the solvent.

Although the content rate (solid content) of the raw material in the said composition for hard-coat layers is not limited, Usually, it is preferable to set it as 5-70 mass%, especially 25-60 mass%.
Depending on the purpose of increasing the hardness of the hard coat layer, suppressing cure shrinkage, controlling the refractive index, imparting anti-glare properties, etc., the hard coat layer composition has a resin, a dispersant, and a surface activity. Agents, other antistatic agents, silane coupling agents, thickeners, anti-coloring agents, coloring agents (pigments, dyes), antifoaming agents, leveling agents, flame retardants, UV absorbers, adhesion promoters, polymerization inhibitors Further, an antioxidant, a surface modifier, etc. may be added.

The method for preparing the hard coat layer composition is not particularly limited as long as each component can be uniformly mixed. For example, the composition can be performed using a known apparatus such as a paint shaker, a bead mill, a kneader, or a mixer.

Specifically, the step of forming the hard coat layer is performed by applying the hard coat layer composition to form a coating film, and curing the obtained coating film. The coating method is not particularly limited. For example, spin coating method, dip method, spray method, die coating method, bar coating method, roll coater method, meniscus coater method, flexographic printing method, screen printing method, pea coater method, etc. Can be mentioned.

Although it does not specifically limit as hardening of the said coating film, It is preferable to form by drying as needed and making it harden | cure by heating, active energy ray irradiation, etc.

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 film thickness is a value measured by observing the cross section with an electron microscope (SEM, TEM, STEM).

Examples of the active energy ray irradiation include irradiation with ultraviolet rays or electron beams. Specific examples of the ultraviolet light source include light sources such as an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc lamp, a black light fluorescent lamp, and a metal halide lamp. As the wavelength of the ultraviolet light, a wavelength range of 190 to 380 nm can be used. Specific examples of the electron beam source include various electron beam accelerators such as a cockcroft-wald type, a bandegraft type, a resonant transformer type, an insulated core transformer type, a linear type, a dynamitron type, and a high frequency type.

Light-transmitting substrate The light-transmitting substrate is preferably one having smoothness and heat resistance and excellent mechanical strength. Specific examples of the material forming the light-transmitting substrate include polyester (polyethylene terephthalate, polyethylene naphthalate), cellulose triacetate, cellulose diacetate, cellulose acetate butyrate, polyester, polyamide, polyimide, polyethersulfone, polysulfone, Examples thereof include thermoplastic resins such as polypropylene, polymethylpentene, polyvinyl chloride, polyvinyl acetal, polyether ketone, polymethyl methacrylate, polycarbonate, and polyurethane, preferably polyester (polyethylene terephthalate, polyethylene naphthalate), cellulose triacetate Is mentioned.

The light-transmitting substrate preferably uses the thermoplastic resin as a flexible film-like material, but uses a plate of these thermoplastic resins depending on the usage mode in which curability is required. It is also possible, or a glass plate plate may be used.

In addition, examples of the light-transmitting substrate include an amorphous olefin polymer (Cyclo-Olefin-Polymer: COP) film having an alicyclic structure. This is a base material in which a norbornene polymer, a monocyclic olefin polymer, a cyclic conjugated diene polymer, a vinyl alicyclic hydrocarbon polymer, or the like is used. ZEONEX, ZEONOR (norbornene resin), Sumilite FS-1700 manufactured by Sumitomo Bakelite Co., Ltd., Arton (modified norbornene resin) manufactured by JSR Corporation, Appel (cyclic olefin copolymer) manufactured by Mitsui Chemicals, Examples include Topas (cyclic olefin copolymer) manufactured by Ticona, Optretz OZ-1000 series (alicyclic acrylic resin) manufactured by Hitachi Chemical Co., Ltd., and the like.
Further, the FV series (low birefringence, low photoelastic modulus film) manufactured by Asahi Kasei Chemicals Corporation is also preferable as an alternative base material for triacetylcellulose.

The thickness of the light-transmitting substrate is preferably 20 μm or more and 300 μm or less, more preferably the upper limit is 200 μm and the lower limit is 30 μm. When the light-transmitting substrate is a plate-like body, the thickness may exceed these thicknesses. The base material is a coating called an anchor agent or primer in addition to physical treatment such as corona discharge treatment and oxidation treatment to improve adhesion when forming a hard coat layer, an antistatic layer, etc. on the substrate. Application may be performed in advance.

The optical layered body 1 of the present invention has other layers (an antiglare layer, a low refractive index layer, an antifouling layer, an adhesive layer, other hard coats) as necessary, as long as light transmittance and the like are not impaired. 1 layer or two or more layers can be appropriately formed. Among these, it is preferable to have at least one of an antiglare layer, a low refractive index layer, and an antifouling layer. These layers may be the same as those of a known antireflection laminate.

Specifically, for example, as shown in FIG. 1, an optical laminated body in which an antiglare layer 4 and a hard coat layer 5 are formed in this order on a light transmissive substrate 3 can be exemplified. . Hereinafter, arbitrary layers will be described.

Antiglare layer The antiglare layer may be formed, for example, between a light-transmitting substrate and a hard coat layer or a low refractive index layer (described later). The antiglare layer may be formed from a composition for an antiglare layer containing a resin and an antiglare agent.

As said resin, it can select from what was demonstrated by the term of the composition for hard-coat layers suitably, and can be used.

As the antiglare agent, various fine particles can be used. The average particle size of the fine particles is not limited, but is generally about 0.01 to 20 μm. Further, the shape of the fine particles may be any of a spherical shape, an elliptical shape, and the like, and preferably a spherical shape. The fine particles include inorganic or organic particles.

The fine particles exhibit anti-glare properties and are preferably transparent. Specific examples of the fine particles include silica beads for inorganic materials and plastic beads for organic materials. Specific examples of plastic beads include styrene beads (refractive index 1.60), 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.

The dry film thickness (at the time of curing) of the antiglare layer is generally about 0.1 to 100 μm, particularly preferably in the range of 0.8 to 10 μm. When the film thickness is within this range, the function as an antiglare layer can be sufficiently exhibited.

The film thickness of the antiglare layer can be measured by the following method.
With a confocal laser microscope (Leica TCS-NT: Leica Co., Ltd .: magnification “300 to 1000 times”), the cross section of the optical laminate can be observed through transmission, the presence or absence of an interface can be determined, and the measurement can be performed according to the following measurement standards. . Specifically, in order to obtain a clear image without halation, a wet objective lens is used for the confocal laser microscope, and about 2 ml of oil having a refractive index of 1.518 is placed on the optical laminate. Judgment. The use of oil is used to eliminate the air layer between the objective lens and the optical laminate.
Measurement procedure 1: The average layer thickness was measured by laser microscope observation.
2: Measurement conditions were as described above.
For every 3: 1 screen, measure the layer thickness from the base material of the maximum uneven part and the minimum concave part one point at a time, and measure it for 5 screens, a total of 10 points, and calculate the average value. And the film thickness of the antiglare layer. This laser microscope can observe a non-destructive cross section by having a refractive index difference in each layer. Moreover, it can obtain | require similarly by performing observation for 5 screens using observation of the SEM and TEM cross-section photograph which can be observed with the difference in the composition of each layer.

Low-refractive index layer The low-refractive index layer is a layer that plays a role of reducing the reflectance when external light (for example, a fluorescent lamp, natural light, etc.) is reflected on the surface of the optical laminate. is there. These low refractive index layers preferably have a refractive index of 1.45 or less, particularly 1.42 or less.
Moreover, although the dry thickness of a low-refractive-index layer is not limited, Usually, what is necessary is just to set suitably from the range of about 30 nm-1 micrometer.

The low refractive index layer is preferably 1) a resin containing silica or magnesium fluoride, 2) a fluorine resin which is a low refractive index resin, 3) a fluorine resin containing silica or magnesium fluoride, and 4) silica. Alternatively, it is composed of a magnesium fluoride thin film or the like. About resin other than the said fluorine-type resin, resin similar to resin which comprises the said composition for hard-coat layers can be used.

As the fluororesin, a polymerizable compound containing a fluorine atom in at least a molecule or a polymer thereof can be used. The polymerizable compound is not particularly limited, and for example, those having a curing reactive group such as an ionizing radiation curable group and a thermosetting polar group are preferable. Moreover, the compound which has these reactive groups simultaneously may be sufficient. In contrast to this polymerizable compound, the polymer has no reactive group as described above.

As the polymerizable compound having an ionizing radiation curable group, fluorine-containing monomers having an ethylenically unsaturated bond can be widely used. More specifically, to illustrate fluoroolefins (eg, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, perfluorobutadiene, perfluoro-2,2-dimethyl-1,3-dioxole, etc.) Can do. As having a (meth) acryloyloxy group, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3,3-pentafluoropropyl (meth) acrylate, 2- (perfluorobutyl) Ethyl (meth) acrylate, 2- (perfluorohexyl) ethyl (meth) acrylate, 2- (perfluorooctyl) ethyl (meth) acrylate, 2- (perfluorodecyl) ethyl (meth) acrylate, α-trifluoromethacryl Fluorinated (meth) acrylate compounds such as methyl acrylate and ethyl α-trifluoromethacrylate; C 1-14 fluoroalkyl group, fluorocycloalkyl group or fluoroalkylene having at least 3 fluorine atoms in the molecule And at least two (meth) acryloyloxy groups There are also fluorine-containing polyfunctional (meth) acrylic acid ester compounds having a silyl group.

Preferable examples of the thermosetting polar group include hydrogen bond forming groups such as a hydroxyl group, a carboxyl group, an amino group, and an epoxy group. These are excellent not only in adhesion to the coating film but also in affinity with inorganic ultrafine particles such as silica. Examples of the polymerizable compound having a thermosetting polar group include 4-fluoroethylene-perfluoroalkyl vinyl ether copolymer; fluoroethylene-hydrocarbon vinyl ether copolymer; epoxy, polyurethane, cellulose, phenol, polyimide, and the like. Fluorine modified products of each resin can be mentioned.

Polymerizable compounds having both ionizing radiation curable groups and thermosetting polar groups include acrylic or methacrylic acid moieties and fully fluorinated alkyl, alkenyl, aryl esters, fully or partially fluorinated vinyl ethers, fully or partially fluorine. Illustrative examples include fluorinated vinyl esters, fully or partially fluorinated vinyl ketones, and the like.

Moreover, as a fluorine resin, the following can be mentioned, for example. Polymer of monomer or monomer mixture containing at least one fluorine-containing (meth) acrylate compound of a polymerizable compound having an ionizing radiation curable group; at least one fluorine-containing (meth) acrylate compound; and methyl (meth) Copolymers with (meth) acrylate compounds that do not contain fluorine atoms in the molecule such as acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate; fluoroethylene , Fluorine-containing compounds such as vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, 3,3,3-trifluoropropylene, 1,1,2-trichloro-3,3,3-trifluoropropylene, hexafluoropropylene Monomer homopolymer or Copolymer such as. Silicone-containing vinylidene fluoride copolymers obtained by adding a silicone component to these copolymers can also be used.

The silicone component is not particularly limited. For example, (poly) dimethylsiloxane, (poly) diethylsiloxane, (poly) diphenylsiloxane, (poly) methylphenylsiloxane, alkyl-modified (poly) dimethylsiloxane, azo group-containing (poly ) Dimethylsiloxane, dimethylsilicone, phenylmethylsilicone, alkyl-aralkyl-modified silicone, fluorosilicone, polyether-modified silicone, fatty acid ester-modified silicone, methylhydrogen silicone, silanol group-containing silicone, alkoxy group-containing silicone, phenol group-containing silicone, methacryl Modified silicone, amino modified silicone, carboxylic acid modified silicone, carbinol modified silicone, epoxy modified silicone, mercapto modified silicone, Tsu-containing modified silicone, polyether-modified silicone are exemplified. Among them, those having a dimethylsiloxane structure are preferable.

More specifically, as the dimethylsiloxane structure, polydimethylsiloxane, polymethylphenylsiloxane, polymethylvinylsiloxane, or other polyalkyl, polyalkenyl, or polyarylsiloxane having a silanol group at the terminal may be added to various crosslinking agents such as tetra Tetrafunctional silanes such as acetoxysilane, tetraalkoxysilane, tetraethylmethyl ketoxime silane, tetraisopropenyl silane, trifunctional silanes such as alkyl or alkenyl triacetoxy silane, triketoxime silane, triisopropenyl silane trialkoxy silane, etc. And those that have been reacted in advance in some cases.

Furthermore, non-polymers or polymers composed of the following compounds can also be used as the fluororesin. That is, a fluorine-containing compound having at least one isocyanato group in the molecule is reacted with a compound having at least one functional group in the molecule that reacts with an isocyanato group such as an amino group, a hydroxyl group, or a carboxyl group. Compound obtained: a compound obtained by reacting a fluorine-containing polyol such as fluorine-containing polyether polyol, fluorine-containing alkyl polyol, fluorine-containing polyester polyol, fluorine-containing ε-caprolactone modified polyol with a compound having an isocyanato group Can be used.

In addition to the above-described polymerizable compound or polymer having a fluorine atom, resin components as described in the hard coat layer composition can be mixed and used. Furthermore, various additives and solvents can be used as appropriate in order to improve the curing agent for curing reactive groups and the like, to improve the coating property, and to impart antifouling properties.

In forming the low refractive index layer, for example, it can be formed using a composition containing a raw material component (a composition for a refractive index layer). More specifically, a raw material component (resin, etc.) and, if necessary, an additive (for example, “fine particles having voids”, a polymerization initiator, an antistatic agent, an antiglare agent, etc., described later) are dissolved or dispersed in a solvent. A low refractive index layer can be obtained by using the resulting solution or dispersion as a composition for a low refractive index layer, forming a coating film from the composition, and curing the coating film. In addition, additives, such as a polymerization initiator, an antistatic agent, and an anti-glare agent, are not specifically limited, A well-known thing can be mentioned.

In the low refractive index layer, it is preferable to use “fine particles having voids” as the low refractive index agent. The “fine particles having voids” can lower 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 at least inside and / or on the surface depending on the form, structure, aggregated state, and dispersed state of the fine particles inside the coating. The low refractive index layer using these fine particles can adjust the refractive index to 1.30 to 1.45.

Examples of the inorganic fine particles having voids include silica fine particles prepared by the method described in JP-A-2001-233611. Further, it may be silica fine particles obtained by the production methods described in JP-A-7-133105, JP-A-2002-79616, JP-A-2006-106714, and the like. 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 a part of the surface of the coating are manufactured for the purpose of increasing the specific surface area in addition to the silica fine particles, and the packing column and the porous surface Examples include a release material that adsorbs various chemical substances on the part, a porous fine particle used for catalyst fixation, a dispersion or aggregate of hollow fine particles intended to be incorporated into a heat insulating material or a low dielectric material. As a specific example, aggregates of porous silica fine particles and silica fine particles 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 diameter of the “fine particles having voids” 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. The average particle diameter is a value measured by a dynamic light scattering method or the like. The “fine particles having voids” are usually about 0.1 to 500 parts by mass, preferably about 10 to 200 parts by mass with respect to 100 parts by mass of the resin in the low refractive index layer.

Examples of the solvent include, but are not limited to, those exemplified for the hard coat layer composition, preferably methyl isobutyl ketone, cyclohexanone, isopropyl alcohol (IPA), n-butanol, t-butanol, diethyl ketone. PGME and the like.

The preparation method of the composition for a low refractive index layer is not particularly limited as long as the components can be mixed uniformly, and may be performed according to a known method. For example, it can mix using the well-known apparatus mentioned above in formation of a hard-coat layer.

The formation method of a coating film should just follow a well-known method. For example, the various methods described above for forming the hard coat layer can be used.

In the formation of the low refractive index layer, the viscosity of the composition for the low refractive index layer is in the range of 0.5 to 5 cps (25 ° C.), preferably 0.7 to 3 cps (25 ° C.) at which preferable coating properties are obtained. Preferably. An antireflection film excellent in visible light can be realized, a uniform thin film with no coating unevenness can be formed, and a low refractive index layer particularly excellent in adhesion to a substrate can be formed.

What is necessary is just to select the hardening method of the obtained coating film suitably according to the content etc. of the composition. For example, in the case of an ultraviolet curing type, the coating film may be cured by irradiating with ultraviolet rays. When a heating means is used for the curing treatment, it is preferable to add a thermal polymerization initiator that generates, for example, a radical by heating to start polymerization of the polymerizable compound.

The film thickness (nm) d _A of the low refractive index layer is expressed by the following formula (I):
d _A = mλ / (4n _A ) (I)
(In the above formula, n _A represents the refractive index of the low refractive index layer, m represents a positive odd number, preferably 1 and λ is a wavelength, preferably a value in the range of 480 to 580 nm) Those satisfying these conditions are preferred.

In the present invention, the low refractive index layer has the following formula (II):
_{120 <n A d A <145} (II)
It is preferable from the viewpoint of low reflectivity.

Antifouling layer The antifouling layer is difficult to adhere to dirt (fingerprints, water-based or oil-based inks, pencils, etc.) on the outermost surface of the optical laminate, or can be easily wiped off even when it adheres. It is a layer that plays a role. According to a preferred embodiment of the present invention, an antifouling layer may be provided for the purpose of preventing the outermost surface of the low refractive index layer from being stained, and in particular, one surface of the light-transmitting substrate on which the low refractive index layer is formed; It is preferable to provide an antifouling layer on both opposite sides. By forming the antifouling layer, the optical laminate can be further improved in antifouling properties and scratch resistance. Even when there is no low refractive index layer, an antifouling layer may be provided for the purpose of preventing contamination on the outermost surface.

In general, the antifouling layer can be formed of a composition containing an antifouling agent and a resin. The antifouling agent is mainly intended to prevent the outermost surface of the optical laminate from being stained, and can also impart scratch resistance to the optical laminate. Examples of the antifouling agent include fluorine compounds, silicon compounds, and mixed compounds thereof. More specifically, silane coupling agents having a fluoroalkyl group, such as 2-perfluorooctylethyltriaminosilane, and the like can be mentioned, and those having an amino group can be preferably used. It does not specifically limit as said resin, Resin illustrated by the above-mentioned composition for hard-coat layers can be mentioned.

The antifouling layer can be formed, for example, on the hard coat layer. In particular, it is desirable to form the antifouling layer so as to be the outermost surface. The antifouling layer can be replaced, for example, by imparting antifouling performance to the hard coat layer itself.

(Optical laminate 2)
Next, the optical laminate 2 of the present invention will be described. The optical layered body 2 of the present invention is formed by forming an antistatic layer and a hard coat layer on a light transmissive substrate. In the optical layered body 2, the antistatic layer contains an organic boron compound, and the solid content of the organic boron compound is preferably 30 to 70% by mass. If the content is less than 30% by mass, sufficient antistatic performance may not be obtained.

Antistatic layer The antistatic layer comprises the organic boron compound and, if necessary, a resin and an additive (for example, a polymerization initiator, an antiglare agent, an antifouling agent, a leveling agent) in a solvent. It can be obtained by using a solution or dispersion obtained by dissolving or dispersing as a composition for an antistatic layer, forming a coating film from the composition, and curing the coating film.

The solvent may be appropriately selected from known solvents according to the type of the organic boron compound to be used, and examples thereof include those exemplified in the hard coat layer composition. As for the said solvent, it is preferable to use a permeable solvent similarly to the said composition for hard-coat layers. In the antistatic composition, the permeable solvent is a permeable solvent that is permeable to the light-transmitting substrate. When such a permeable solvent swells and wets the light-transmitting substrate, a part of the composition for the antistatic layer permeates to the light-transmitting substrate. By this, high intensity | strength can be obtained similarly to the case where the said composition for hard-coat layers osmose | permeates. Furthermore, the organic boron compound can be present in a sufficiently dispersed state without aggregating in the antistatic layer, and excellent antistatic performance can be maintained.

The resin is not particularly limited, and examples thereof include an ionizing radiation curable resin, a solvent drying resin, and a thermosetting resin. These resins are not particularly limited, and examples thereof include those described above. In particular, it is preferable to use an ionizing radiation curable resin that has high transparency, has durability against heat and light, and does not inhibit the antistatic function after curing.

In addition to the components described above, an additive may be added to the antistatic layer composition as necessary. Examples of the additive include resins other than those described above, surfactants, coupling agents, thickeners, anti-coloring agents, coloring agents such as pigments or dyes, antifoaming agents, leveling agents, flame retardants, ultraviolet absorbers, Infrared absorbers, adhesion-imparting agents, polymerization inhibitors, antioxidants, surface modifiers and the like can be mentioned. As these, known materials usually used for an antistatic layer can be used.

The method for preparing the antistatic layer composition is not particularly limited as long as each component can be uniformly mixed, and may be carried out according to a known method. For example, a known apparatus such as a paint shaker, a bead mill, a kneader, or a mixer can be used.

Specifically, the antistatic layer in the present invention is formed by coating the antistatic layer composition on a light-transmitting substrate to form a coating film, and then curing the obtained coating film. Done. The coating method is not particularly limited. For example, spin coating method, dip method, spray method, dye coating method, bar coating method, roll coater method, meniscus coater method, flexographic printing method, screen printing method, and pea coater method. And the like.

After the formation of the coating film, curing may be performed as necessary. Although it does not specifically limit as said hardening method, Although it can select suitably according to the kind etc. of resin to be used, For example, it can harden | cure by irradiation of energy rays, such as an ultraviolet-ray.

The thickness (dry thickness) of the antistatic layer is usually about 10 to 500 nm, and preferably 50 to 200 nm. When the thickness is less than 10 nm, it is desirable for optical performance such as total light transmittance and haze, but the desired antistatic performance (saturation band voltage less than 2.0 kV) may not be obtained. Also, when the thickness exceeds 500 nm, it takes a very long time for the cross-sectional phase of the hard coat layer to exist in the light-transmitting substrate via the antistatic layer, which is inefficient in terms of production processing There is a risk of becoming. For the reasons described above, it is preferable to set the film thickness within the above range. The thickness of the antistatic layer can also be measured in the same manner as the hard coat layer.

The optical laminate 2 of the present invention is an optical laminate comprising an antistatic layer and a hard coat layer on a light transmissive substrate. In the optical layered body 2, the hard coat layer may or may not contain the organic boron compound.

In the optical laminate 2, when the hard coat layer contains an organic boron compound, it is preferable to form the hard coat layer described in the optical laminate 1. When the hard coat layer does not contain an organic boron compound in the optical laminate 2, the hard coat layer is made of the same composition as the hard coat layer composition described in the optical laminate 1 except that the organic boron compound is not contained. It is preferable to form.

The hard coat layer in the optical layered body 2 preferably contains a permeable solvent that is permeable to the light-transmitting substrate and the antistatic layer. When such a permeable solvent swells and wets the light-transmitting substrate, a part of the hard coat layer composition permeates to the light-transmitting substrate through the antistatic layer. Thereby, high strength can be obtained. Such a permeable solvent is not particularly limited, and examples thereof include those described above.

The optical layered body 2 of the present invention appropriately comprises one or more other layers (antiglare layer, low refractive index layer, antifouling layer, adhesive layer, other hard coat layer, etc.) as necessary. You may have. These layers may be the same as those of a known antireflection laminate, and for example, those described above can be used. Specifically, for example, as shown in FIG. 2, an antistatic layer 6 and a hard coat layer 5 are formed in this order on a light-transmitting substrate 3, and an antifouling layer 7 is further formed. An optical laminated body etc. can be mentioned.

By providing the optical laminate according to the present invention on the surface of the polarizing element on the surface opposite to the surface where the hard coat layer is present in the optical laminate, a polarizing plate can be obtained.
The polarizing element is not particularly limited, and for example, a polyvinyl alcohol film, a polyvinyl formal film, a polyvinyl acetal film, an ethylene-vinyl acetate copolymer saponified film, etc. dyed and stretched with iodine or the like can be used. In the laminating process of the polarizing element and the optical laminate of the present invention, it is preferable to saponify the light-transmitting substrate (preferably a triacetyl cellulose film). By the saponification treatment, the adhesiveness is improved and an antistatic effect can be obtained.

It can also be set as the image display apparatus provided with the said optical laminated body or the said polarizing plate on the outermost surface. The image display device may be a non-self-luminous image display device such as an LCD, or a self-luminous image display device such as a PDP, FED, ELD (organic EL, inorganic EL), or CRT.

An LCD as a typical example of the non-spontaneous light emission type includes a transmissive display body and a light source device that irradiates the transmissive display body from the back. When the image display device is an LCD, the optical laminate of the present invention or the above-described polarizing plate is formed on the surface of the transmissive display body.

In the case of the liquid crystal display device having the optical laminated body, the light source of the light source device is irradiated from the lower side of the optical laminated body. Note that in the STN liquid crystal display device, a retardation plate may be inserted between the liquid crystal display element and the polarizing plate. An adhesive layer may be provided between the layers of the liquid crystal display device as necessary.

The PDP, which is the self-luminous image display device, has a front glass substrate (electrodes are formed on the surface) and a rear glass substrate (electrodes and minute electrodes) disposed with a discharge gas sealed between the front glass substrate and the front glass substrate. Are formed on the surface, and red, green, and blue phosphor layers are formed in the groove). When the image display device is a PDP, the above-described optical laminate is provided on the surface of the surface glass substrate or the front plate (glass substrate or film substrate).

The self-luminous image display device is an ELD device that emits light when a voltage is applied, such as zinc sulfide and a diamine substance: a phosphor is deposited on a glass substrate, and the voltage applied to the substrate is controlled. It may be an image display device such as a CRT that converts light into light and generates an image visible to the human eye. In this case, the optical laminated body described above is provided on the outermost surface of each display device as described above or the surface of the front plate.

In any case, the image display device can be used for display of a television, a computer, a word processor, or the like. In particular, it can be suitably used for the surface of high-definition image displays such as CRT, liquid crystal panel, PDP, ELD, FED and the like.

The optical layered body of the present invention maintains transparency, exhibits stable antistatic performance, and can suppress the occurrence of rust on the coater and the like during production. Therefore, the optical laminate of the present invention can be suitably applied to a cathode ray tube display (CRT), a liquid crystal display (LCD), a plasma display (PDP), an electroluminescence display (ELD) and the like.

The features of the present invention will be described more specifically with reference to the following examples and comparative examples. However, the scope of the present invention is not limited to the examples.

Example 1
A biaxially stretched polyethylene terephthalate film (trade name “A4300”, manufactured by Toyobo Co., Ltd.) having a thickness of 100 μm was used as a transparent substrate, and high boron (manufactured by Boron International) was bar-coated with a Mayer bar as a composition for an antistatic layer. Then, the antistatic layer having a dry film thickness of 200 nm was formed by drying in a 70 ° C. blowing oven for 30 seconds and removing the solvent.
Subsequently, the following hard coat layer composition was bar-coated, and after removing the solvent by drying, the hard coat layer was cured by irradiating with ultraviolet rays at an irradiation dose of 100 mJ / cm ² to form a hard coat layer having a coating thickness of 5 μm. And an optical laminate was obtained.

Preparation of hard coat layer composition A component having the following composition was blended to prepare a hard coat layer coating composition.
100 parts by mass of pentaerythritol triacrylate (Nippon Kayaku Co., Ltd., trade name: PET30)
Methyl ethyl ketone 43 parts by mass Leveling agent 2 parts by mass (Dainippon Ink Chemical Co., Ltd., trade name: MCF-350-5)
Polymerization initiator 6 parts by mass (Ciba Specialty Chemicals Co., Ltd., trade name: Irgacure 184)

Example 2
A boron-based antistatic material prepared in the same manner as in Example 1, using a biaxially stretched polyethylene terephthalate film (trade name “A4300”, manufactured by Toyobo Co., Ltd.) having a thickness of 100 μm as a transparent substrate. After the bar coating of the hard coat layer composition containing the composition with a Meyer bar, after removing the solvent by drying, the hard coat layer was cured by irradiating with ultraviolet rays at an irradiation dose of 100 mJ / cm ² , and a coating film of 5 μm An antistatic hard coat layer was formed to obtain an optical laminate.

Preparation of antistatic hard coat layer composition An antistatic hard coat layer coating composition was prepared by blending the components of the following composition.
70 parts by mass of pentaerythritol triacrylate (Nippon Kayaku Co., Ltd., trade name: PET30)
High boron (manufactured by Boron International) 30 parts by mass Methyl ethyl ketone 43 parts by mass Leveling agent 2 parts by mass (Dainippon Ink Chemical Co., Ltd., trade name: MCF-350-5)
Polymerization initiator 6 parts by mass (Ciba Specialty Chemicals Co., Ltd., trade name: Irgacure 184)

Comparative Example 1
A hard coat layer composition prepared in the same manner as in Example 2 except that Sanconol TBX (containing a lithium ion conduction type antistatic agent; manufactured by Sanko Chemical Industry Co., Ltd.) was used instead of high boron. Apply using a winding rod (Meyer's bar) # 14 for coating, heat dry in an oven at 70 ° C for 1 minute, evaporate the solvent, and then irradiate with ultraviolet rays to a dose of 30 mJ. The film was cured to form a hard coat layer to obtain an optical laminate.

Comparative Example 2
An optical laminate was obtained in the same manner as in Example 1 except that Sanconol TBX was used as the composition for the antistatic layer.

Comparative Example 3
An optical laminate was obtained in the same manner as in Example 1 except that polyaniline (electron-conducting conductive polymer material, manufactured by Sigma-Aldrich) was used as the antistatic layer composition.

About the obtained optical laminated body, the surface resistivity in each measurement environment of Table 1 was measured, and it evaluated as a parameter | index of antistatic performance. Moreover, each optical laminated body was fixed to the inner surface of a glass bottle, after adding a trace amount of pure water, it sealed, and the presence or absence of the rusting after leaving to stand in 100 degreeC oven for 10 hours was evaluated. The results are shown in Table 1.

It was shown that the optical laminates obtained by the examples exhibited stable antistatic performance without being affected by the environment. On the other hand, it was shown that the optical laminate obtained by the comparative example was greatly affected by the use environment, and the antistatic performance was lowered particularly under low humidity. Furthermore, it was shown that the optical laminates obtained by the examples are very stable because rust generation hardly occurs.

According to the present invention, it is possible to obtain an optical laminate that maintains transparency, stably exhibits antistatic performance, and can suppress the occurrence of rust on a printing machine or the like during production. The optical laminate of the present invention can be suitably applied to a cathode ray tube display (CRT), a liquid crystal display (LCD), a plasma display (PDP), an electroluminescence display (ELD) and the like.

It is an example of the optical laminated body of this invention. It is an example of the optical laminated body of this invention.

Explanation of symbols

3 Light-transmitting substrate 4 Antiglare layer 5 Hard coat layer 6 Antistatic layer 7 Antifouling layer

Claims (6)

An optical laminate comprising a hard coat layer on a light transmissive substrate,
The hard coat layer contains an organoboron compound ,
The optical laminated body, wherein the organic boron compound is an ionic conjugate of polyether, polyaldehyde or polyketone and boron . An optical laminate comprising an antistatic layer and a hard coat layer on a light transmissive substrate,
The antistatic layer contains an organic boron compound ,
The optical laminated body, wherein the organic boron compound is an ionic conjugate of polyether, polyaldehyde or polyketone and boron . The hard coat layer is formed of a hard coat layer composition containing a resin, a solvent, and an organic boron compound,
The optical layered body according to claim 1, wherein the solvent comprises a permeable solvent. The antistatic layer is formed of a composition for an antistatic layer containing a resin, a solvent, and an organic boron compound,
The optical layered body according to claim 2, wherein the solvent comprises a permeable solvent. A polarizing plate comprising a polarizing element,
Polarized light characterized in that the optical layered body according to claim 1, 2, 3 or 4 is provided on the surface of the polarizing element on a surface opposite to the surface on which the hard coat layer is present in the optical layered body. Board. An image display device comprising the optical laminate according to claim 1, 3, or 4 or the polarizing plate according to claim 5 on an outermost surface.

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