JP5678544B2 - Optical laminate, front plate and image display device - Google Patents

Description

The present invention relates to an optical laminate, a front plate, and an image display device.

2. Description of the Related Art A liquid crystal display (LCD) or the like is known in which a front plate having a glass substrate or the like bonded to the front surface of a display is installed in order to give a high-class feeling. On the front plate, an optical laminate for preventing reflection by light scattering or interference is bonded to both sides or one side of a glass substrate or the like.

As such an optical layered body, one having a hard coat layer and a low refractive index layer on a substrate made of triacetylcellulose has been conventionally known. The hard coat layer is a layer that gives strength to the optical film.
On the other hand, the low refractive index layer is a layer having a lower refractive index than the base material and the hard coat layer, and is a layer mainly for preventing reflection of light (Patent Documents 1 to 3). The low refractive index layer is generally formed by adding a material having a low refractive index, such as hollow silica or fluorine resin.

By the way, in such an optical laminated body, in recent years, simplification of the manufacturing process has been attempted in order to reduce the manufacturing cost. As a method for simplifying the production process, for example, a method of directly forming a low refractive index layer on a triacetyl cellulose substrate can be considered.
However, when a conventional low refractive index layer is directly formed on a triacetyl cellulose substrate, there is a problem that the film strength of the low refractive index layer is lowered and the scratch resistance is lowered.

JP 2002-006103 A JP 2006-293278 A JP 2007-264277 A

An object of the present invention is to provide an optical laminate that has excellent film strength and scratch resistance, can simplify the manufacturing process, and can reduce manufacturing costs.

The present invention is an optical laminate having a triacetyl cellulose base material and a low refractive index layer adjacent to the triacetyl cellulose base material, and the steel wool resistance of the low refractive index layer side surface is the same as or steel wool resistance of triacetyl cellulose substrate or from rather high, the low refractive index layer, a hollow silica, fluorinated resin, the low refractive index layer composition containing an acrylic resin and a solvent It is related with the optical laminated body characterized by being formed using .
Upper Symbol solvent is preferably a methyl isobutyl ketone and / or t- butanol.
The acrylic resin preferably contains at least one selected from the group consisting of a dimer of pentaerythritol triacrylate, dipentaerythritol hexa (meth) acrylate, and dipentaerythritol hexa (meth) acrylate. .

The present invention is also an optical laminate having a triacetyl cellulose base material and a low refractive index layer adjacent to the triacetyl cellulose base material, and the reflectance Y value is 0.6 to 1.0%. der is, the low refractive index layer, a hollow silica, fluorinated resin, an optical laminate characterized by being formed by using the composition for a low refractive index layer containing an acrylic resin and a solvent.
The present invention is also a front plate to be attached to the front surface of the image display device, comprising an antireflection film on one surface of the substrate via an adhesive layer, and the above-described surface on the other surface of the substrate via an adhesive layer. The present invention relates to a front plate characterized by comprising the above optical laminate.
The present invention also relates to an image display device comprising the above-described front plate so that the antireflection film is the outermost surface.
Hereinafter, the present invention will be described in detail.

1st this invention is an optical laminated body which has a low-refractive-index layer adjacent on a triacetylcellulose base material, Comprising: The surface of the said low-refractive-index layer has a specific physical-property value. For this reason, the optical layered body of the first present invention has excellent film strength and scratch resistance.

(Triacetyl cellulose base material)
The optical laminated body of 1st this invention has a triacetyl cellulose (TAC) base material.
The triacetyl cellulose base material is optically non-anisotropic, has smoothness and heat resistance, and is excellent in mechanical strength.

The thickness of the triacetyl cellulose base material is preferably 20 to 300 μm, more preferably the upper limit is 200 μm and the lower limit is 30 μm.

(Low refractive index layer)
The optical layered body of the first aspect of the present invention has a low refractive index layer adjacent to the triacetylcellulose base material.
The low refractive index layer is a layer having a refractive index lower than the refractive index of the triacetyl cellulose base material constituting the optical laminate of the first invention, and usually has a refractive index of less than 1.5, The layer is more preferably 1.45 or less, and still more preferably 1.35 or less.

The low refractive index layer is preferably formed using a composition for a low refractive index layer containing hollow silica, a fluorine-based resin, an acrylic resin, and a solvent. In the present specification, the fluororesin and the acrylic resin are hereinafter collectively referred to as a binder resin. Further, in the present specification, “resin” is a concept including resin components such as monomers and oligomers.

The hollow silica fine particles serve to lower the refractive index while maintaining the layer strength of the low refractive index layer. In the present specification, “hollow silica fine particles” refers to a structure in which gas is filled and / or a porous structure containing a gas, and the gas occupancy rate compared to the original refractive index of silica fine particles. Means a silica fine particle whose refractive index decreases in inverse proportion to
Further, in the present invention, the nanoporous structure is formed on at least a part of the inside and / or the surface depending on the form, structure, aggregation state, and dispersion state of the coating film using the above composition for low refractive index layer. Also included are silica particulates capable of forming a structure.

Specific examples of the hollow silica fine particles are not particularly limited, and for example, silica fine particles prepared using a technique disclosed in Japanese Patent Application Laid-Open No. 2001-233611 are preferable. Since hollow silica fine particles are easy to manufacture and have high hardness themselves, when mixed with an organic binder to form a low refractive index layer, the layer strength is improved and the refractive index is adjusted to be low. It becomes possible to do.

In addition to the above-mentioned silica fine particles, the silica fine particles capable of forming a nanoporous structure inside and / or at least part of the surface of the coating film are manufactured and used for the purpose of increasing the specific surface area. Columns, adsorbents that adsorb various chemicals on the porous portion of the surface, porous fine particles used for catalyst fixation, or dispersions or aggregates of hollow fine particles intended to be incorporated into heat insulating materials or low dielectric materials A collection is mentioned. As such a specific example, as a commercial product, an assembly of porous silica fine particles from the product names Nippil and Nipgel manufactured by Nippon Silica Kogyo Co., Ltd. And colloidal silica UP series (trade name). Among these, those within the preferred particle diameter range of the present invention can be used.

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

In the low refractive index layer composition, the content of the hollow silica fine particles is not particularly limited, but is preferably 200 parts by mass or less with respect to 100 parts by mass of the binder resin solid content. If it exceeds 200 parts by mass, the low refractive index layer to be formed cannot be made sufficiently low in refractive index, but the strength may be insufficient. A more preferred lower limit is 10 parts by mass, and a more preferred upper limit is 165 parts by mass.

Examples of the fluorine resin include a polymerizable compound containing a fluorine atom in at least a molecule or a polymer thereof. Although it does not specifically limit as said polymeric compound, For example, it has hardening reactive groups, such as a functional group (ionizing radiation curable group) hardened | cured with ionizing radiation, and a polar group (thermosetting polar group) hardened | cured with heat. Those are preferred. Moreover, the compound which has these reactive groups simultaneously may be sufficient.

As the polymerizable compound having an ionizing radiation curable group containing a fluorine atom, 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 (Meth) acrylate compounds having fluorine atoms in the molecule, such as methyl acrylate and ethyl α-trifluoromethacrylate; C 1-14 fluoroalkyl groups having at least 3 fluorine atoms in the molecule, fluorocyclo An alkyl group or a fluoroalkylene group and at least two (meta And fluorine-containing polyfunctional (meth) acrylic acid ester compounds having an acryloyloxy group.

Examples of the polymerizable compound having a thermosetting polar group containing a fluorine atom include 4-fluoroethylene-perfluoroalkyl vinyl ether copolymer; fluoroethylene-hydrocarbon vinyl ether copolymer; epoxy, polyurethane, cellulose, Illustrative examples include fluorine-modified products of resins such as phenol and polyimide. As said thermosetting polar group, hydrogen bond forming groups, such as a hydroxyl group, a carboxyl group, an amino group, an epoxy group, are mentioned preferably, for example. These are excellent not only in adhesion to the coating film but also in affinity with inorganic ultrafine particles such as silica.

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.

Examples of the polymer of the polymerizable compound containing a fluorine atom include a polymer of a monomer or a monomer mixture containing at least one fluorine-containing (meth) acrylate compound of the polymerizable compound having the ionizing radiation curable group; At least one fluorine (meth) acrylate compound and a fluorine atom in a molecule such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate Copolymers with (meth) acrylate compounds not containing; fluoroethylene, vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, 3,3,3-trifluoropropylene, 1,1,2-trichloro-3, 3,3-trifluoropropylene, hex Homopolymers and copolymers of fluorine-containing monomers such as hexafluoropropylene; and the like.

Moreover, the silicone containing vinylidene fluoride copolymer which made these copolymers contain a silicone component can also be used as a polymer of the said polymeric compound. Examples of silicone components in this case include (poly) dimethylsiloxane, (poly) diethylsiloxane, (poly) diphenylsiloxane, (poly) methylphenylsiloxane, alkyl-modified (poly) dimethylsiloxane, azo group-containing (poly) dimethylsiloxane, , Dimethyl silicone, phenylmethyl silicone, alkyl aralkyl modified silicone, fluorosilicone, polyether modified silicone, fatty acid ester modified silicone, methyl hydrogen silicone, silanol group containing silicone, alkoxy group containing silicone, phenol group containing silicone, methacryl modified silicone, Acrylic modified silicone, amino modified silicone, carboxylic acid modified silicone, carbinol modified silicone, epoxy modified silicone, mercapto modified silicone Corn, fluorine-modified silicones, polyether-modified silicones and the like. Among them, those having a dimethylsiloxane structure are preferable.

In addition to the above, a fluorine-containing compound having at least one isocyanato group in the molecule, and 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 A compound obtained by reacting a fluorine-containing polyether polyol, a fluorine-containing alkyl polyol, a fluorine-containing polyester polyol, a fluorine-containing polyol such as a fluorine-containing ε-caprolactone-modified polyol, and a compound having an isocyanato group. Compounds; etc. can also be used as the fluororesin.

The fluororesin may be one that is generally commercially available.
Especially, as a commercial item of the said fluorine-type resin, TU2224 (made by JSR), AR110 (made by Daikin) are the points which can make the refractive index of a low refractive index layer small and can improve abrasion resistance. And LINC3A (manufactured by Kyoeisha Chemical Co., Ltd.) are preferable.

As said acrylic resin, the acrylic compound which has a 1 or 2 or more unsaturated bond can be mentioned, for example. Examples of the acrylic compound having one unsaturated bond include ethyl (meth) acrylate and ethylhexyl (meth) acrylate. Examples of acrylic compounds having two or more unsaturated bonds include trimethylolpropane tri (meth) acrylate, hexanediol (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, and pentaerythritol. Multifunctional compounds such as tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentylglycol di (meth) acrylate, or the above-mentioned polyfunctional compounds and (meta ) Reaction products such as acrylates (for example, poly (meth) acrylate esters of polyhydric alcohols) or dimers of the above polyfunctional compounds. In the present specification, “(meth) acrylate” refers to methacrylate and acrylate.
Moreover, what has polyfunctionality, such as modified | denatured (meth) acryl acrylates, such as urethane acrylate, ester acrylate, epoxy acrylate, ether acrylate, can be mentioned as said acrylic resin.

Among these, as the acrylic resin, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and dipentaerythritol hexa (meth) acrylate are excellent in scratch resistance and transparency. More preferably, it contains at least one selected from the group consisting of dimers.

In the low refractive index layer composition, the total content of the fluororesin and the acrylic resin is preferably 30 to 90% by mass in the solid content of the low refractive index layer composition. If it is less than 30% by mass, the scratch resistance may be lowered. If it exceeds 90% by mass, the reflectance may increase. The total content is more preferably 35 to 50% by mass in terms of solid content.

In the low refractive index layer composition, the content ratio of the fluororesin and the acrylic resin is preferably 20/80 to 90/10 in terms of solid content.
If the ratio of the fluororesin is less than the above range, the refractive index may not be sufficiently lowered, and if it exceeds the above range, scratch resistance may be reduced.
The content ratio is more preferably 20/80 to 85/15.

As the solvent, a solvent that hardly penetrates into the triacetylcellulose base material and has a low boiling point and can be easily dried is preferable. The boiling point of the solvent is preferably 120 ° C. or lower.
Specifically, as the solvent, for example, a solvent having a relatively high molecular weight such as methyl isobutyl ketone and hardly permeating the triacetyl cellulose base material and an alcohol solvent such as t-butanol and IPA are preferable.
Especially, as said solvent, it is more preferable that they are methyl isobutyl ketone and / or t-butanol.

The composition for a low refractive index layer may contain other components in addition to the hollow silica, the fluorine-based resin, and the acrylic resin described above. Examples of the other components include a photopolymerization initiator, a leveling agent, a crosslinking agent, a curing agent, a polymerization accelerator, a viscosity modifier, a refractive index adjuster, an antistatic agent, and an antifouling agent. These may be known ones.

The low refractive index layer composition preferably has a solid content of 2 to 4.5% by mass. When the solid content is less than 2% by mass, drying is slow, and the solvent may penetrate into the triacetyl cellulose base material. If it exceeds 4.5% by mass, the film surface may be abnormal. The solid content is more preferably 2.5 to 3% by mass.

The composition for a low refractive index layer may be prepared by mixing and dispersing the hollow silica, fluorine resin, acrylic resin and other components as required in the solvent.
The method of mixing and dispersing is not particularly limited, and may be a known method, and may be performed using a known device such as a paint shaker, a bead mill, or a kneader.

The low refractive index layer is formed by applying the low refractive index layer composition on a triacetyl cellulose base material to form a coating film, drying it as necessary, and curing the coating film. be able to.
Examples of the coating method include various known methods such as spin coating, dipping, spraying, die coating, bar coating, roll coater, meniscus coater, flexographic printing, screen printing, and bead coater. A method can be mentioned.

The method for curing the coating film is not particularly limited, and any known method may be used. Examples thereof include a method for curing the coating film by irradiating it with ultraviolet rays.

The film thickness (nm) d _A of the low refractive index layer is 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.

In the optical laminated body of the first aspect of the present invention, the low refractive index layer is formed using the above-described composition for low refractive index layer.
Here, when a low refractive index layer is formed directly on a triacetyl cellulose substrate using a conventional composition for a low refractive index layer containing a low refractive index agent and a binder resin, the film strength and scratch resistance are improved. Only a low one was obtained. This is because the triacetyl cellulose base material is a material that allows easy penetration of the solvent and binder resin, and therefore the binder resin in the low refractive index layer composition has permeated into the triacetyl cellulose base material. it is conceivable that.
In the present invention, since the composition for a low refractive index layer comprising the above-mentioned specific components is used, the penetration of the binder resin in the composition for a low refractive index layer can be suppressed, and the triacetyl cellulose substrate In addition, a low refractive index layer having excellent film strength and scratch resistance can be suitably formed directly without involving other layers. As a result, the manufacturing process of the optical laminate can be simplified and the manufacturing cost can be reduced.

That is, it is preferable that the optical layered body of the first aspect of the present invention does not have an osmotic layer formed by osmosis of the composition for low refractive index layer into the triacetyl cellulose base material. The permeation layer is a layer formed by permeating the triacetyl cellulose base material with an acrylic resin or a solvent contained in the low refractive index layer composition.
The presence or absence of the permeation layer can be observed by observing the cross section of the optical layered body with a microscope such as SEM.

The optical layered body of the first aspect of the present invention may have other arbitrary layers in addition to the above-described triacetyl cellulose base material and low refractive index layer. Examples of the optional layer include an antifouling layer. These are formed on the low refractive index layer. The antifouling layer can be formed by, for example, a known method by mixing a known antifouling agent and the like with a resin and a solvent.

In the optical layered body of the first aspect of the present invention having the above-described configuration, the steel wool resistance of the surface on the low refractive index layer side is the same as or higher than the steel wool resistance of the triacetyl cellulose substrate.
When the steel wool resistance of the surface of the low refractive index layer is lower than the steel wool resistance of the triacetyl cellulose base material, an optical laminate having desired scratch resistance cannot be obtained.
Note that the steel wool resistance is obtained by reciprocating the surface of the low refractive index layer and the triacetyl cellulose base material with a # 0000 steel wool with a friction load of 50 g / cm ² for a predetermined number of times. Evaluation is based on the number of scratches observed. For example, when the number of scratches is larger in the same number of reciprocating frictions, it is defined that the steel wool resistance is low.

The optical layered body of the first invention preferably has a total light transmittance of 90% or more. If it is less than 90%, color reproducibility and visibility may be impaired when the optical laminate of the present invention is mounted on the surface of an image display device. The total light transmittance is more preferably 95% or more, and still more preferably 98% or more.
The total light transmittance can be measured by a method based on JIS K-7361 using a haze meter (manufactured by Murakami Color Research Laboratory, product number: HM-150).

The optical layered body of the first invention preferably has a haze of 1.0% or less. If it exceeds 1.0%, the color reproducibility and visibility may be impaired when mounted on the display surface, and a desired contrast may not be obtained. The haze is more preferably 0.1 to 0.6%.
The haze can be measured by a method based on JIS K-7136 using a haze meter (manufactured by Murakami Color Research Laboratory, product number: HM-150).

2nd this invention is an optical laminated body which has a triacetylcellulose base material and a low-refractive-index layer adjacent on the said triacetylcellulose base material, Comprising: The reflectance Y value is 0.6-1. It is an optical laminated body characterized by being 0%.
Since the optical layered body of the second aspect of the present invention has the reflectance Y value in the specific range described above, it has excellent antireflection performance. Moreover, since such an optical laminated body is obtained only by having a low refractive index layer on a triacetyl cellulose base material, a manufacturing process can be simplified and manufacturing cost can be reduced.
When the reflectance Y value is less than 0.6%, the scratch resistance is lowered, and appearance defects such as drying unevenness are liable to occur. If it exceeds 1.0%, the transmittance may be lowered, or reflection prevention may be insufficient.
The reflectance Y value can be obtained by measuring by a 5-degree reflection measurement method using a spectroscope “MPC-3100PC” manufactured by Shimadzu Corp.

Examples of the triacetylcellulose substrate in the optical laminate of the second invention include the same triacetylcellulose substrates as used in the optical laminate of the first invention described above.

Examples of the low refractive index layer in the optical layered body of the second invention include those similar to the low refractive index layer of the optical layered body of the first invention described above.
The low refractive index layer can be formed by the same material and method as those of the low refractive index layer of the optical laminate of the first invention described above.

In the optical layered body of the second aspect of the present invention, the total light transmittance and haze preferably have the total light transmittance and haze of the optical layered body of the first aspect of the present invention described above.
The optical layered body of the second aspect of the present invention can be formed by the same method as the optical layered body of the first aspect of the present invention described above.

The optical laminates of the first and second inventions are provided with an antireflection film on one surface of a substrate via an adhesive layer, and the invention described above via an adhesive layer on the other surface of the substrate. By providing this optical laminate, it is possible to provide a front plate to be attached to the front surface of the image display device.
Such a front plate is also one aspect of the present invention.

Examples of the substrate include a glass substrate and an acrylic substrate.
The thickness of the substrate is preferably 0.1 to 5 mm, and more preferably 0.5 to 3 mm.
Examples of the pressure-sensitive adhesive include publicly known acrylic pressure-sensitive adhesives, urethane pressure-sensitive adhesives, silicone pressure-sensitive adhesives, and water-based pressure-sensitive adhesives.
The thickness of the pressure-sensitive adhesive layer is preferably 25 to 30 μm.

The antireflection film is not particularly limited as long as it is a known antireflection performance or antiglare optical film, but is an antireflection film having a light-transmitting substrate, a hard coat layer, and a low refractive index layer. It is preferable.
The light transmissive substrate, the hard coat layer, and the low refractive index layer can be obtained using known materials and forming methods.
In addition, when bonding the said antireflection film and the optical laminated body of this invention to the said board | substrate, each base material side is bonded together to a board | substrate through an adhesive layer.

An example of a schematic cross-sectional view of the front plate of the present invention is shown in FIG.
The front plate shown in FIG. 1 is composed of the optical laminate 1, the pressure-sensitive adhesive layer 2, the substrate 3, the pressure-sensitive adhesive layer 2, and the antireflection film 4 described above in order from the image display device side.
By installing the front plate on the image display device so that the antireflection film is on the viewing side, the image display device has high light transmittance, does not generate a double image, and has excellent antireflection performance; can do.
A known method may be used as the method for installing the front plate.

Examples of the image display device include a non-self-luminous image display device such as a liquid crystal display (LCD), a plasma display panel (PDP), a field emission display (FED), and an electroluminescence display (ELD) (organic EL, inorganic EL). And a self-luminous image display device such as a CRT.
An image display device provided with such a front plate is also one aspect of the present invention.

In any case, the optical layered body of the present invention can be used for display display of a television, a computer, a word processor or the like. In particular, it can be suitably used for the back side of the front plate of high-definition image displays such as CRT, liquid crystal panel, PDP, ELD and the like.

Since the optical layered body of the present invention has the above-described configuration, it has excellent film strength and scratch resistance.
Therefore, the optical layered body of the present invention is suitably used for displays such as cathode ray tube display devices (CRT), liquid crystal displays (LCD), plasma displays (PDP), electroluminescence displays (ELD), and particularly high definition displays. can do.

It is an example of the cross-sectional schematic diagram of the front board provided with the optical laminated body of this invention.

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples and comparative examples.
In the text, “part” or “%” is based on mass unless otherwise specified.

Example 1
A triacetyl cellulose (TAC) base material (thickness 80 μm, TD80UL manufactured by Fuji Film Co., Ltd.) was prepared, and on one side of the TAC base material, the composition 1 for a low refractive index layer prepared with the composition shown below was applied. The film was applied to a thickness of 0.1 μm (after drying) to form a coating film. Next, the formed coating film is dried in a thermal oven at a temperature of 50 ° C. for 60 seconds, the solvent in the coating film is evaporated, and the coating film is cured by irradiating the coating film with ultraviolet rays so that the irradiation dose becomes 100 mj. Thus, a low refractive index layer was formed, and the optical layered body of Example 1 was obtained.
<Composition 1 for low refractive index layer>
Hollow silica (average primary particle size 60 nm, through rear 4320 (trade name), manufactured by Catalyst Kasei Co., Ltd.)
1.6 parts by mass fluorine resin (TU2224 (trade name), manufactured by JSR) 1.0 part by mass dipentaerythritol hexaacrylate 0.3 parts by mass Irgacure 127: 0.1 parts by mass methyl isobutyl ketone (Ciba Japan) MIBK) 97.0 parts by mass

(Example 2)
In Example 1, the optical laminate of Example 2 was used in the same manner as in Example 1 except that the composition 2 for low refractive index layer having the following composition was used instead of the composition 1 for low refractive index layer. Got.
<Composition 2 for low refractive index layer>
Hollow silica (average primary particle size 60 nm, through rear 4320 (trade name), manufactured by Catalyst Kasei Co., Ltd.)
1.6 parts by mass fluorine resin (TU2224 (trade name), manufactured by JSR) 1.1 parts by mass dipentaerythritol hexaacrylate 0.2 parts by mass Irgacure 127: 0.1 parts by mass methyl isobutyl ketone (Ciba Japan) MIBK) 97.0 parts by mass

Example 3
In Example 1, the optical laminate of Example 3 was used in the same manner as Example 1 except that the composition 3 for low refractive index layer having the following composition was used instead of the composition 1 for low refractive index layer. Got.
<Composition 3 for low refractive index layer>
Hollow silica (average primary particle size 60 nm, through rear 4320 (trade name), manufactured by Catalyst Kasei Co., Ltd.)
1.6 parts by mass fluorine resin (TU2224 (trade name), manufactured by JSR) 0.8 parts by mass dipentaerythritol hexaacrylate 0.5 parts by mass Irgacure 127: 0.1 parts by mass methyl isobutyl ketone (manufactured by Ciba Japan) MIBK) 97.0 parts by mass

Example 4
In Example 1, the optical laminate of Example 4 was used in the same manner as in Example 1 except that the composition 4 for low refractive index layer having the following composition was used instead of the composition 1 for low refractive index layer. Got.
<Low refractive index layer composition 4>
Hollow silica (average primary particle size 60 nm, through rear 4320 (trade name), manufactured by Catalyst Kasei Co., Ltd.)
1.5 parts by mass fluorine resin (TU2224 (trade name), manufactured by JSR) 1.05 parts by mass dipentaerythritol hexaacrylate 0.35 parts by mass Irgacure 127: 0.1 parts by mass methyl isobutyl ketone (Ciba Japan) MIBK) 97.0 parts by mass

(Example 5)
In Example 1, the optical laminate of Example 5 was used in the same manner as in Example 1 except that the composition 5 for low refractive index layer having the following composition was used instead of the composition 1 for low refractive index layer. Got.
<Composition 5 for low refractive index layer>
Hollow silica (average primary particle size 60 nm, through rear 4320 (trade name), manufactured by Catalyst Kasei Co., Ltd.)
1.6 parts by mass fluorine resin (TU2224 (trade name), manufactured by JSR) 1.0 part by mass dipentaerythritol hexaacrylate 0.3 parts by mass Irgacure 127: 0.1 part by mass t-butanol manufactured by Ciba Japan .0 parts by mass

(Example 6)
In Example 1, the optical laminate of Example 6 was used in the same manner as in Example 1 except that the composition 6 for low refractive index layer having the following composition was used instead of the composition 1 for low refractive index layer. Got.
<Composition 6 for low refractive index layer>
Hollow silica (average primary particle size 60 nm, through rear 4320 (trade name), manufactured by Catalyst Kasei Co., Ltd.)
1.6 parts by mass fluorine resin (TU2224 (trade name), manufactured by JSR) 1.0 part by mass dipentaerythritol hexaacrylate dimer 0.3 parts by mass Irgacure 127: 0.1 parts by mass methyl by Ciba Japan 97.0 parts by mass of isobutyl ketone (MIBK)

(Example 7)
In Example 1, the optical laminate of Example 7 was used in the same manner as in Example 1, except that the composition 7 for low refractive index layer having the following composition was used instead of the composition 1 for low refractive index layer. Got.
<Composition 7 for low refractive index layer>
Hollow silica (average primary particle size 60 nm, through rear 4320 (trade name), manufactured by Catalyst Kasei Co., Ltd.)
1.7 parts by mass fluorine resin (TU2224 (trade name), manufactured by JSR) 0.95 parts by mass dipentaerythritol hexaacrylate 0.25 parts by mass Irgacure 127: 0.1 parts by mass methyl isobutyl ketone (Ciba Japan) MIBK) 97.0 parts by mass

(Comparative Example 1)
In Example 1, the optical laminate of Comparative Example 1 was used in the same manner as in Example 1 except that instead of the composition 1 for low refractive index layer, the composition 8 for low refractive index layer having the following composition was used. Got.
<Low refractive index layer composition 8>
Hollow silica (average primary particle size 60 nm, through rear 4320 (trade name), manufactured by Catalyst Kasei Co., Ltd.)
1.6 parts by mass fluorine resin (TU2224 (trade name), manufactured by JSR) 1.0 part by mass dipentaerythritol hexaacrylate 0.3 parts by mass Irgacure 127: 0.1 parts by mass methyl ethyl ketone (MEK) manufactured by Ciba Japan 97.0 parts by mass

(Comparative Example 2)
In Example 1, the optical laminate of Comparative Example 2 was prepared in the same manner as in Example 1 except that the composition 9 for low refractive index layer having the following composition was used instead of the composition 1 for low refractive index layer. Got.
<Low refractive index layer composition 9>
Hollow silica (average primary particle size 60 nm, through rear 4320 (trade name), manufactured by Catalyst Kasei Co., Ltd.)
1.6 parts by mass fluorine resin (TU2224 (trade name), manufactured by JSR) 1.0 part by mass dipentaerythritol hexaacrylate 0.3 parts by mass Irgacure 127: 0.1 part by mass polyglycidyl methacrylate (by Ciba Japan) PGMA) 97.0 parts by mass

(Comparative Example 3)
In Example 1, the optical laminate of Comparative Example 3 was used in the same manner as Example 1 except that the composition 10 for low refractive index layer having the following composition was used instead of the composition 1 for low refractive index layer. Got.
<Low refractive index layer composition 10>
Hollow silica (average primary particle size 60 nm, through rear 4320 (trade name), manufactured by Catalyst Kasei Co., Ltd.)
1.6 parts by mass fluorine resin (TU2224 (trade name), manufactured by JSR Corporation) 1.0 part by mass dipentaerythritol hexaacrylate 0.3 parts by mass Irgacure 127: 0.1 part by mass n-propyl acetate by Ciba Japan .0 parts by mass

About each obtained optical laminated body, the following item was evaluated. The evaluation results are shown in Table 1.
<Steel Wool (SW) resistance>
The surface of the low refractive index layer of the optical laminate was reciprocated with a friction load of 50 g / cm ² using # 0000 steel wool, and the number of reciprocations where the surface began to scratch and the appearance of the scratch by visual observation As compared with the case of reciprocating friction in the same manner on the surface of the triacetylcellulose substrate, the following criteria were evaluated.
○: Equivalent to the triacetylcellulose substrate or few scratches.
X: The scratch was easier to enter than the triacetyl cellulose base material.

<Nail scratch>
The nail of the index finger is set up vertically with respect to the surface of the low refractive index layer, and the state of the surface after 10 reciprocations in the horizontal direction at a load of 500 to 600 g and a speed of 1 reciprocation / 1 second is visually observed. evaluated.
○: No scratch.
X: There is a crack.

<Reflectance Y value>
About the reflectance Y value of each optical laminated body, it measured by the 5 degree | times reflection measuring method using the spectroscope "MPC-3100PC" Shimadzu Corp. make.

<Haze>
About the haze of each optical laminated body, it measured by the method based on JISK-7136 (haze) using the haze meter (Murakami Color Research Laboratory make, product number; HM-150).

From Table 1, the optical laminated body of the Example was favorable in all items of scratch resistance, antireflection property, and haze.

The optical laminate of the present invention can be suitably used for high definition displays such as a liquid crystal display (LCD), a plasma display (PDP), and an electroluminescence display (ELD), and is particularly suitable as a front plate of these displays. Can be used for

DESCRIPTION OF SYMBOLS 1 Optical laminated body of this invention 2 Adhesive layer 3 Board | substrate
4 Antireflection film

Claims (6)

An optical laminate having a triacetyl cellulose base material and a low refractive index layer adjacent to the triacetyl cellulose base material,
The steel wool resistance of the low refractive index layer side surface, the same or more rather high and steel wool resistance of the triacetyl cellulose substrate,
The optical laminated body, wherein the low refractive index layer is formed using a composition for a low refractive index layer containing hollow silica, a fluorine resin, an acrylic resin, and a solvent . Solvents, methyl isobutyl ketone and / or t- butanol in a claim 1 laminated body for optical purposes according. The acrylic resin contains at least one selected from the group consisting of a dimer of pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and dipentaerythritol hexa (meth) acrylate. Item 3. The optical laminate according to Item 1 or 2 . An optical laminate having a triacetyl cellulose base material and a low refractive index layer adjacent to the triacetyl cellulose base material,
Reflectivity Y value Ri 0.6 to 1.0% der,
The optical laminated body, wherein the low refractive index layer is formed using a composition for a low refractive index layer containing hollow silica, a fluorine resin, an acrylic resin, and a solvent . A front plate attached to the front surface of the image display device, comprising an antireflection film on one surface of the substrate via an adhesive layer, and an adhesive layer on the other surface of the substrate. A front plate comprising the optical laminate according to 3 or 4 . An image display device comprising the front plate according to claim 5 so that the antireflection film becomes the outermost surface.

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