JP2016132187A - Optical laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical laminate having high hardness and excellent starch resistance and suppressing curling.SOLUTION: The optical laminate includes a first hard coat layer formed on one surface of a light-transmitting substrate, and a second hard coat layer formed on an opposite surface side of the first hard coat layer to the light-transmitting substrate side. The first hard coat layer is formed by using a first composition for a hard coat layer, which comprises first silica fine particles and a first resin component, and the first hard coat layer has a permeation layer formed by permeation of the first resin component into the light-transmitting substrate and a non-permeation layer formed of the first composition for a hard coat layer. The second hard coat layer is formed by using a second composition for a hard coat layer, which comprises second silica fine particles and a second resin component, and the second hard coat layer contains a dispersion in which the first resin component is dispersed in a sea-island state.SELECTED DRAWING: None

Description

The present invention relates to an optical laminate.

Image display surfaces of image display devices such as cathode ray tube display (CRT), liquid crystal display (LCD), plasma display (PDP), electroluminescence display (ELD), field emission display (FED) are not damaged during handling. Thus, it is required to impart scratch resistance.
In response to such demands, for example, an optical layered body in which a hard coat (HC) layer is provided on a light-transmitting substrate or an optical function such as antireflection and antiglare properties is used is used. Thus, it is common to improve the scratch resistance of the image display surface of the image display device.

Conventionally, as a method of improving the hardness of the hard coat layer, there is a method of adding inorganic fine particles. Generally, an optical laminate in which a hard coat layer with inorganic fine particles added is provided on a light-transmitting substrate is manufactured. (For example, see Patent Document 1).

However, in recent years, there has been a demand for an optical laminate including a hard coat layer having further excellent scratch resistance and hardness.
As a method for making such a hard coat layer higher in hardness, for example, in Patent Document 2, a first hard coat layer containing reactive silica fine particles and a binder component is provided on a light-transmitting substrate. A hard coat film in which a second hard coat layer is provided on the first hard coat layer is disclosed.

Here, in recent image display devices, as the display screen is enlarged, the demand for thinning is increasing, and the light-transmitting substrate used for the optical laminate is also thinner than before. It is coming.
However, when a conventional hard coat layer with a high hardness is formed on such a light-transmitting substrate having a reduced thickness, there is a problem that large curls are generated.

JP 2008-107762 A JP 2010-131771 A

The present invention has been made in view of the above situation, and an object of the present invention is to provide an optical laminate having high hardness and excellent scratch resistance, and curling is suppressed.

In the present invention, a first hard coat layer is formed on one surface of a light transmissive substrate, and a second hard coat layer is formed on a side surface opposite to the light transmissive substrate side of the first hard coat layer. An optical laminate in which a hard coat layer is formed, wherein the first hard coat layer is formed using a first hard coat layer composition comprising first silica fine particles and a first resin component. And a penetration layer formed by the first resin component penetrating into the light transmissive substrate, and a non-penetrating layer formed by the first hard coat layer composition. The second hard coat layer is formed by using a second hard coat layer composition containing second silica fine particles and a second resin component, and the first hard coat layer Characterized in that the resin component contains a dispersion dispersed in a sea-island shape. It is a laminate.

In the optical layered body of the present invention, it is preferable that the first resin component dispersed in the sea-island shape is contained unevenly on the first hard coat layer side of the second hard coat layer.

Further, the Vickers hardness (N1) of the cross section of the second hard coat layer, the Vickers hardness (N2) of the cross section of the non-penetrable layer of the first hard coat layer, and the Vickers hardness (N3) of the cross section of the light-transmitting substrate. Are measured by a nanoindentation method at a load of 10 mN, the Vickers hardness (N1) is 600 to 1300 MPa, the Vickers hardness (N2) is 250 to 500 MPa, and the Vickers hardness (N3 ) Is preferably 250 to 335 MPa.

It is preferable that the thickness of the first hard coat layer is 2 to 7 μm, the thickness of the second hard coat layer is 2 to 7 μm, and the thickness of the light-transmitting substrate is 15 to 45 μm.
The first resin component is preferably a thermoplastic resin.
The present invention is described in detail below.

As a result of intensive studies on an optical laminate in which a hard coat layer is formed on a light-transmitting substrate, the inventors have determined that the hard coat layer is a first hard coat layer and a second hard coat layer. And having a structure with a sea-island structure formed by eluting the resin component of the first hard coat layer into the second hard coat layer, and having an excellent hardness and a light-transmitting substrate. It has been found that even when the film thickness is reduced, curling can be suitably prevented.
In addition, in optical laminates with a hard coat layer provided on a light transmissive substrate, interference fringes are generated due to interface reflection of incident light due to the difference in refractive index between the light transmissive substrate and the hard coat layer. Is a problem.
For this reason, as a result of further studies, the present inventors have penetrated the resin component constituting the first hard coat layer in the vicinity of the interface on the first hard coat layer side of the light transmissive substrate. Providing a permeation layer, and the first hard coat layer comprising the permeation layer and a non-permeation layer not penetrating into the light-transmitting substrate can suitably prevent the occurrence of interference fringes. The headline and the present invention were completed.

In the present invention, a first hard coat layer is formed on one surface of a light transmissive substrate, and a second hard coat layer is formed on a side surface opposite to the light transmissive substrate side of the first hard coat layer. This is an optical laminate in which a hard coat layer is formed.

The optical layered body of the present invention has a light transmissive substrate.
The material of the light transmissive substrate is preferably triacetyl cellulose. The light-transmitting substrate formed using the triacetyl cellulose as a material has transparency, smoothness, and heat resistance, and is excellent in mechanical strength.
The thickness of the light transmissive substrate is preferably 15 to 45 μm. If it is less than 15 μm, the hardness of the optical laminate of the present invention may be insufficient, and if it exceeds 45 μm, the optical laminate of the present invention will be thick, which can sufficiently meet the recent demand for thin film. It may become impossible. The more preferable lower limit of the thickness of the light-transmitting substrate is 20 μm, and the more preferable upper limit is 40 μm.
In addition, when forming the first hard coat layer thereon, in addition to physical treatment such as corona discharge treatment, plasma discharge treatment, oxidation treatment, etc., Chemical treatment such as saponification treatment or solvent treatment, and application of a paint called an anchor agent or primer (thickness is about 1 μm) may be performed in advance.

In the optical layered body of the present invention, the first hard coat layer is formed on one surface of the light transmissive substrate, and the first hard coat layer is on the side opposite to the light transmissive substrate side. In addition, a second hard coat layer is formed.
In the optical layered body of the present invention, the first hard coat layer is a layer having a lower hardness than a second hard coat layer described later. By having such a low-hardness first hard coat layer, the optical laminate of the present invention can relieve internal stress, and as a result, the occurrence of curling can be suitably prevented.

The first hard coat layer is formed using a first hard coat layer composition containing first silica fine particles and a first resin component.
Although it does not specifically limit as said 1st silica fine particle, For example, colloidal silica is mentioned.
The colloidal silica is preferably surface-treated colloidal silica. Examples of the surface-treated colloidal silica include colloidal silica having an ultraviolet-reactive functional group on the surface. The ultraviolet reactive functional group is not particularly limited, and examples thereof include an acrylate group, a methacrylate group, an epoxy group, and a vinyl group.
Such colloidal silica having an ultraviolet reactive functional group on the surface can be obtained, for example, by a method of reacting the surface of the first silica fine particles with the silane coupling agent having the ultraviolet reactive functional group.
It does not specifically limit as said silane coupling agent, A well-known thing can be mentioned, For example, KBM-502, KBM-503, KBE-502, KBE-503, KBM-5803, KBM-4803, KBM-1083 (Trade names, all manufactured by Shin-Etsu Chemical Co., Ltd.).

The average particle size of the colloidal silica is preferably 5 to 100 nm. When the thickness is less than 5 nm, it is difficult to produce colloidal silica having a uniform particle size. Moreover, there is a possibility that the aggregation of particles becomes large. Moreover, there exists a possibility that the viscosity of a coating liquid may become high and coating property may deteriorate. If it exceeds 100 nm, the haze is improved and the light transmittance is also lowered, which is not preferable. The minimum with a more preferable average particle diameter of the said colloidal silica is 10 nm, and a more preferable upper limit is 60 nm.
The said average particle diameter is a value obtained by observing and measuring the cross section of the optical laminated body of this invention with an electron microscope (SEM, TEM, STEM). The average particle diameter of the colloidal silica shows the same numerical value even in a dispersed state in the ink or in the first hard coat layer after formation.
In the optical layered body of the present invention, the colloidal silica may be used as one kind, or two or more kinds having different average particle diameters may be mixed and used.

The colloidal silica is preferably in the form of single particles and / or irregular particles in the first hard coat layer composition.
In the optical layered body of the present invention, the form of the colloidal silica in the first hard coat layer forming composition may be either a single particle shape or an irregular particle shape. Since the saponification resistance and the pencil hardness of the hard coat layer are improved, it is more preferably irregularly shaped particles.
Here, the term “irregular particle shape” means a state in which 3 to 20 spherical colloidal silicas are bonded by an inorganic chemical bond. Such deformed particulate colloidal silica can be easily formed by using the above-described surface-treated colloidal silica.
The above-mentioned irregular shaped colloidal silica is in a state in which spherical colloidal silica is bound by an inorganic chemical bond, so it has a robust property that is difficult to crush when subjected to an external pushing force such as a pencil hardness test. Yes. In addition, irregularly shaped colloidal silica has an advantage that the surface area is wide and the adhesive strength with the pentaerythritol tri (meth) acrylate or the like is increased due to its shape. Therefore, atypical particulate colloidal silica is difficult to peel off and has improved saponification resistance and the like. Furthermore, the irregular-shaped colloidal silica is physically strong because the irregular-shaped colloidal silica is entangled randomly.
In addition, even in the case of single-particulate silica, when the particle size becomes large (for example, the average particle size is 30 nm or more), when a large external pressing force such as a pencil hardness test is applied, the silica becomes difficult to crush and peels off. The saponification resistance is improved.
Furthermore, even when the particle size of the monoparticulate silica is reduced (for example, the average particle size is less than 30 nm), the hardness near the surface of the first hard coat layer is increased, so that the SW resistance is improved. Results are also obtained.

Examples of the commercially available colloidal silica include IPAST, IPASTS, IPASTMS, IPASTL, IPASTZL, IPASTUP, MIBKSD, MIBKSDL, MIBKSDML, MIBKSDZL (all trade names, manufactured by Nissan Chemical Co., Ltd.), V8803 (JGC Catalysts & Chemicals). And NS

It is preferable that the compounding quantity of the said colloidal silica is 5-40 mass% with respect to 100 mass% in total with the solid content of the 1st resin component of the composition for 1st hard-coat layers. If it is less than 5% by mass, the hardness of the first hard coat layer may be insufficient, and if it exceeds 40% by mass, the adhesion with the second hard coat layer may deteriorate or haze may deteriorate. Sometimes. The minimum with more preferable compounding quantity of the said colloidal silica is 10 mass%, and a more preferable upper limit is 30 mass%.

Although it does not specifically limit as said 1st resin component, For example, it is preferable that it is a thermoplastic resin. In the present specification, “resin” is a concept including resin components such as monomers and oligomers.
The thermoplastic resin is not particularly limited. For example, a styrene resin, a (meth) acrylic resin, a vinyl acetate resin, a vinyl ether resin, a halogen-containing resin, an alicyclic olefin resin, a polycarbonate resin, or a polyester resin. Resins, polyamide resins, cellulose derivatives, silicone resins and rubber or elastomers can be mentioned.
The thermoplastic resin is preferably amorphous and soluble in an organic solvent (particularly a common solvent capable of dissolving a plurality of polymers and curable compounds). In particular, from the viewpoints of film forming properties, transparency, and weather resistance, styrene resins, (meth) acrylic resins, alicyclic olefin resins, polyester resins, cellulose derivatives (cellulose esters, etc.) and the like are preferable.
In the present specification, (meth) acryl means acryl and methacryl.
As said thermoplastic resin, it is preferable that a glass transition temperature is 70 degreeC or more.
Moreover, the said thermoplastic resin may have a functional group hardened | cured with an ultraviolet-ray or an electron beam in a molecule | numerator. Since the glass transition temperature of the thermoplastic resin tends to decrease due to the introduction of functional groups that are cured by ultraviolet rays or electron beams into the molecule, the glass transition temperature is 70 ° C. or higher in the state before curing. It is preferable that a functional group that is cured by ultraviolet rays or electron beams is introduced into the molecule.

The first resin component may contain, for example, an ionizing radiation curable resin that is a resin curable by ultraviolet rays or electron beams.
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 ( (Meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyfunctional urethane (meth) acrylate , Polyfunctional compounds such as polyfunctional epoxy (meth) acrylates, or reaction products of the above polyfunctional compounds with (meth) acrylates, etc. (for example, poly (meth) acrylates of polyhydric alcohols) Ester) and the like. Furthermore, the compound which gave modification | denaturation, such as ethylene oxide of the compound mentioned above, propylene oxide, caprolactone, or isocyanuric acid, may be sufficient.

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.

The first resin component may contain a thermosetting resin.
The thermosetting resin is not particularly limited. For example, phenol resin, urea resin, diallyl phthalate resin, melamine resin, guanamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin, aminoalkyd resin, melamine-urea cocondensation Examples thereof include resins, silicon resins, polysiloxane resins, and the like.

When the first resin component includes an ionizing radiation curable resin and the ionizing radiation curable resin is used as an ultraviolet curable resin, it is preferable to use a photopolymerization initiator.
Examples of the photopolymerization initiator include acetophenones (for example, trade name Irgacure 184, 1-hydroxy-cyclohexyl-phenyl-ketone manufactured by BASF Corporation, trade name Irgacure 907, BASF 2-methyl-1 [4- ( Methylthio) phenyl] -2-morpholinopropan-1-one), benzophenones, thioxanthones, benzoin, benzoin methyl ether, aromatic diazonium salts, aromatic sulfonium salts, aromatic iodonium salts, metallocene compounds, benzoin sulfonic acids Examples include esters. These may be used alone or in combination of two or more.
Also, trade name Irgacure 127 (2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) benzyl] -phenyl} -2-methyl-propan-1-one manufactured by BASF) And 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 and 2-dimethylamino-2- (4methyl-benzyl) -1- (4-morpholin-4-yl- Phenyl) -butan-1-one can also be used in combination.
Furthermore, commercially available products other than the above can also be used. Specifically, Irgacure 369, Irgacure 379, Irgacure 819, Irgacure 500, Irgacure 754, Irgacure 250, Irgacure 1800, Irgacure 1870, Irgacure 2959, Irgacure OXE01, manufactured by BASF DAROCUR TPO, DAROCUR1173, Japan Siber Hegner Co. SpeedcureMBB, SpeedcurePBZ, SpeedcureITX, SpeedcureCTX, SpeedcureEDB, Esacure ONE, Esacure KIP150, Esacure KTO46, manufactured by Nippon Kayaku Co., Ltd. of KAYACURE DETX-S, KAYACURE CTX, KAYACURE BMS, KAYACURE DM I, and the like.

The first hard coat layer composition may contain other components as necessary in addition to the components described above. As the other components, resins other than the resin components, thermal polymerization initiators, photoacid generators, ultraviolet absorbers, light stabilizers, leveling agents, antifouling agents, crosslinking agents, curing agents, polymerization accelerators, A viscosity modifier, an antistatic agent, an antioxidant, an antibacterial agent, a slip agent, a refractive index modifier, a dispersant, an antiblocking agent, a colorant and the like can be mentioned. These can use a well-known thing.

The first hard coat layer composition can be prepared by dispersing the above-described first silica fine particles, the resin component, and, if necessary, other components in a solvent. The method for preparing the first 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. .

The first hard coat layer is formed by, for example, drying a coating film formed by applying the first hard coat layer composition onto the light-transmitting substrate and curing it by ionizing radiation irradiation or heating. Can be formed.
However, as will be described later, in the optical laminate of the present invention, the second hard coat layer contains a dispersion in which the first resin component is dispersed in a sea-island shape. The coating film obtained by applying the composition onto the light-transmitting substrate is not completely cured and then the second hard coat layer is not formed, but in the half-cured (half-cured) state, the second hard coat layer is formed. A coat layer is formed.
When the first resin component is a thermoplastic resin having a glass transition temperature of 100 ° C. or higher, the thermoplastic resin is added to adjust the solid content when the first hard coat layer composition is applied. Since it is a resin (solvent drying type resin) that becomes a film only by drying the solvent, the coating film of the first composition for hard coat layer does not need to be cured by ionizing radiation irradiation or the like.
When the first resin component is a thermoplastic resin having a glass transition temperature of less than 100 ° C., the optical laminate of the present invention is manufactured by roll-to-roll, so that the coating film is prevented from sticking to the guide roll. Therefore, it is preferable to perform a half cure (semi-curing) by ionizing radiation irradiation on the coating film.
In addition, it is preferable to perform irradiation, such as ionizing radiation, to the coating film of said 1st composition for hard-coat layers in the air or the environment where oxygen concentration is high. By irradiating the coating film of the first hard coat layer composition with ionizing radiation or the like under such an environment, the coating film can be easily made into a half-cure, and is formed on the coating film. It becomes easy to improve the elution control of the first resin component into the hard coat layer and the adhesion with the second hard coat layer.

The method for applying the first hard coat layer composition onto the light-transmitting substrate is not particularly limited. For example, the spin coat method, the dip method, the spray method, the die coat method, the bar coat method, and the roll coater method. , Known methods such as a meniscus coater method, a flexographic printing method, a screen printing method, and a pead coater method.

In addition, as a method of irradiating ionizing radiation when curing the coating film after drying, for example, a light source 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, or a metal halide lamp is used. A method is mentioned.
Moreover, as a wavelength of an ultraviolet-ray, the wavelength range of 190-380 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.

The solvent can be selected and used according to the type and solubility of the resin component used. For example, 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.), carbonates (dimethyl carbonate, ethyl methyl carbonate), halogenated Carbons (dichloromethane, dichloroethane, etc.), esters (methyl acetate, ethyl acetate, butyl acetate, isopropyl acetate, PGMEA, etc.), alcohols (ethanol, isopropanol, butanol, cyclohexanol, etc.), glycols; methyl glycol, methyl Examples include recall acetate, PGME, cellosolves (methyl cellosolve, ethyl cellosolve, etc.), cellosolve acetates, sulfoxides (dimethylsulfoxide, etc.), amides (dimethylformamide, dimethylacetamide, etc.), etc. Also good.

It is preferable that the said solvent contains the permeable solvent which has a permeability | transmittance with respect to the transparent base material (henceforth a TAC base material) which consists of a triacetyl cellulose especially. In the present invention, the “permeability” of the osmotic solvent is meant to include all concepts such as permeability to the TAC substrate, swelling property, and wettability.
When the light-transmitting substrate is a TAC substrate, such a permeable solvent swells and wets the TAC substrate, so that a part of the first hard coat layer composition penetrates the TAC substrate. A permeation layer in which the resin component of the first hard coat layer has permeated is formed in the vicinity of the interface of the TAC substrate, these interfaces can be substantially eliminated, and the generation of interference fringes can be prevented; and The adhesion between the TAC substrate and the first hard coat layer can be improved.

Specific examples of the osmotic solvent include ketones; acetone, methyl ethyl ketone, cyclohexanone, methyl isobutyl ketone, diacetone alcohol, esters; methyl formate, methyl acetate, ethyl acetate, butyl acetate, isopropyl 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, chloroform, tetrachloroethane, glycol ethers; methyl cellosolve, ethyl cellosolve, butyl cellosolve, cellosolve acetate, other, dimethyl sulfoxide Propylene carbonate, dimethyl carbonate, ethyl methyl carbonate, or mixtures thereof.
Preferably, methyl acetate, ethyl acetate, methyl ethyl ketone, dimethyl carbonate, ethyl methyl carbonate and the like are used.
Other solvents can also be used by mixing with the permeable solvent.

In the optical layered body of the present invention, the first hard coat layer includes a penetrating layer formed by penetrating the first resin component described above into the light-transmitting substrate, and the first hard coat layer. And a non-permeable layer formed by the composition for use.
By having the first hard coat layer having such a configuration, the optical laminate of the present invention suitably generates interference fringes due to interface reflection between the light-transmitting substrate and the first hard coat layer. In addition, the adhesion between the light-transmitting substrate and the first hard coat layer is extremely excellent.

Such a first hard coat layer preferably has a thickness (total film thickness of the osmotic layer and the non-penetrable layer described above) of 2 to 7 μm. If it is less than 2 μm, both the permeation part and the non-penetration part are expressed, so that the production margin is very narrow and it becomes difficult to manufacture, and the optical characteristics and mechanical characteristics of the optical laminate become unstable. The hardness of the laminate may be insufficient, the adhesion with the light-transmitting substrate may be deteriorated, or interference fringes may be easily generated.
On the other hand, if the thickness exceeds 7 μm, the optical laminate of the present invention may curl or not sufficiently meet the demand for thinning, and the adhesion with the second hard coat layer also deteriorates. Or interference fringes may occur between the second hard coat layer and the first hard coat layer.

The thickness of the osmotic layer in the first hard coat layer is not particularly limited, but the thickness of the osmotic layer is equal to the thickness of the first hard coat layer (the total thickness of the osmotic layer and the non-penetrable layer described above). It is preferable that it is 15 to 85%. If it is less than 15%, interference fringes are likely to occur. If it exceeds 85%, the optical properties and mechanical properties of the optical laminate of the present invention become unstable, and the hardness is insufficient. Sometimes it becomes.
In the present specification, the thickness of the first hard coat layer and the thicknesses of the penetrating layer and the non-penetrating layer can be measured by observing the optical laminate of the present invention with a cross-sectional microscope.

In the optical layered body of the present invention, the second hard coat layer is formed using a second hard coat layer composition containing second silica fine particles and a second resin component. .
Examples of the second silica fine particles and the second resin component include the same as the first silica fine particles and the first resin component in the first hard coat layer described above. The method for preparing the coating layer composition may be the same method as the first hard coating layer composition.
The average particle size of the second silica fine particles may be the same as or different from the average particle size of the first silica fine particles.
In the optical layered body of the present invention, the second hard coat layer is a layer having higher hardness than the first hard coat layer described above. By having such a high hardness second hard coat layer, the optical layered body of the present invention has excellent scratch resistance.
In the optical layered body of the present invention, the specific composition of the first hard coat layer composition and / or the second hard coat layer composition includes the hardness of the first hard coat layer and the second hard coat layer composition. The hardness of the hard coat layer is appropriately adjusted so as to have the specific relationship described above.

In the second hard coat layer, the amount of the second silica fine particles is 25 to 25% with respect to 100% by mass in total with the solid content of the second resin component of the second hard coat layer composition. It is preferable that it is 60 mass%. If it is less than 25% by mass, the hardness of the second hard coat layer may be insufficient. If it exceeds 60% by mass, the adhesion with the first hard coat layer may be deteriorated, or an optical laminate may be used. The haze may deteriorate, and the scratch resistance may deteriorate.
A more preferable lower limit of the blending amount of the second silica fine particles is 30% by mass, and a more preferable upper limit is 50% by mass.

The second hard coat layer contains a dispersion in which the first resin component described above is dispersed in a sea-island shape. By containing such a dispersion, not only the adhesion with the first hard coat layer is improved, but also interference fringes can be suitably prevented.
Here, the state that "the first resin component contains a dispersion dispersed in a sea-island state" can be confirmed by cross-sectional observation of the second hard coat layer, specifically, In the cross section of the second hard coat layer, in the second silica fine particles in a uniformly dispersed state, the first resin component is a massive region in which almost no second silica fine particles are present, and the region The dispersion state is clearly observed in a non-uniform state as compared with the second silica fine particles in the uniformly dispersed state. The “bulk region in which almost no second silica fine particles are present” includes the case where no second silica fine particles are present in the massive region.

In the second hard coat layer, the area ratio of the first resin component in the cross section in the thickness direction is preferably 5 to 15%. If it is less than 5%, the adhesion with the first hard coat layer cannot be improved, and interference fringes may not be sufficiently prevented. On the other hand, if it exceeds 15%, the refractive index of the second hard coat layer may increase to cause (internal) haze to become white, and the hardness may be insufficient. When the thickness of the non-penetrating layer of the first hard coat layer is thin, the non-penetrating layer component of the first hard coat layer elutes to the second hard coat layer side. In some cases, the adhesion to the hard coat layer may deteriorate. The area ratio of the first resin component in the cross section in the thickness direction is more preferably 10% or less.
In addition, the area ratio is binarized from the cross-sectional photograph of the second hard coat layer by TEM using the image analysis software Win Roof (Mitani Corporation, Visual System Department). The area of the region that is 0.01 μm ² or more can be measured and obtained.

In the second hard coat layer, the first resin component dispersed in a sea-island shape is preferably unevenly distributed on the first hard coat layer side of the second hard coat layer. By including the first resin component in the second hard coat layer in such a state, the adhesion is improved and interference fringes can be suitably prevented.
On the other hand, if there is a large amount of the first resin component on the surface opposite to the first hard coat layer side of the second hard coat layer, the scratch resistance may deteriorate.
Here, the above-mentioned “contained unevenly on the first hard coat layer side of the second hard coat layer” can be confirmed by cross-sectional observation of the second hard coat layer, The first hard coat layer side (hereinafter referred to as the lower region) from the opposite side (hereinafter also referred to as the upper region) of the line connecting the midpoints in the thickness direction of the cross section of the second hard coat layer. Also means that a large amount of the first resin component is dispersed.
More specifically, when the area ratio described above is measured, the area ratio of the first resin component in the lower region is 1.5-2. It is preferably 3 times.

The thickness of the second hard coat layer is preferably 2 to 7 μm. If it is less than 2 μm, the optical laminate of the present invention may have insufficient hardness, and if it exceeds 7 μm, the optical laminate of the present invention may curl or sufficiently meet the demand for thinning. May not be possible. The more preferable lower limit of the thickness of the second hard coat layer is 3 μm, and the more preferable upper limit is 6 μm.

As a method for forming such a second hard coat layer, for example, the above-described second hard coat layer is applied to the above-mentioned half-cured or coated film of the first hard coat layer composition. After forming the coating film of the second hard coat layer by applying the composition, the coating film of the second hard coat layer can be dried and cured by ionizing radiation irradiation or heating. . The half-cured first hard coat layer is formed by forming a coating film of the second hard coat layer composition on the coating film of the first hard coat layer composition that has been half-cured and drying it. The first resin component in the coating film of the composition is eluted into the coating film of the second hard coat layer composition, and the second hard coat layer has the first resin component dispersed in a sea-island shape. The dispersion will be contained.
When the coating film of the second hard coat layer composition is cured, it is preferable to cure the half-cured coating film of the first hard coat layer composition together.
Moreover, it is preferable to perform irradiation, such as ionizing radiation, to the coating film of the composition for 2nd hard-coat layers in a low oxygen concentration environment. By irradiating with ionizing radiation in a low oxygen concentration environment, the coating film of the second hard coat layer composition is cured without breaking the sea-island structure of the first resin component eluted in the coating film. Can be made.

The optical layered body of the present invention has the above-described Vickers hardness (N1) of the cross section of the second hard coat layer, Vickers hardness (N2) of the cross section of the non-penetrable layer of the first hard coat layer, and the light-transmitting substrate. When the Vickers hardness (N3) of the cross section is measured by a nanoindentation method at a load of 10 mN, the Vickers hardness (N1) is 600 to 1300 MPa, and the Vickers hardness (N2) is 250 to 500 MPa. And the Vickers hardness (N3) is preferably 250 to 335 MPa. When the Vickers hardness (N1), (N2), and (N3) are within the above ranges, the optical layered body of the present invention has both curl generation and excellent hardness.

When the Vickers hardness (N1) of the cross section of the second hard coat layer is less than 600 MPa, the surface hardness of the optical laminate of the present invention does not reach the target pencil hardness, and the scratch resistance is insufficient. May be. On the other hand, when the Vickers hardness (N1) exceeds 1300 MPa, the Vickers hardness (N1) becomes too hard and becomes brittle, and the crack property (toughness) may be lowered. Also, the curl becomes stronger, and in the post-processing process, there is a problem (for example, the curl becomes stronger in the saponification process and does not pass through the production line. Curling, etc.). Furthermore, the surface hardness of the optical layered body of the present invention does not reach the target pencil hardness of 3H.
A more preferable lower limit of the Vickers hardness (N1) is 650 MPa, a more preferable upper limit is 1250 MPa, a still more preferable lower limit is 700 MPa, and a still more preferable upper limit is 1200 MPa.
In the optical layered body of the present invention, the Vickers hardness (N1) is measured by pushing a Vickers indenter into the cross section of the second hard coat layer as will be described later.
The position where the Vickers indenter is pushed is preferably near the surface opposite to the first hard coat layer side of the cross section of the second hard coat layer. The Vickers hardness (N1) measured by pushing the Vickers indenter into such a position is regarded as the Vickers hardness of the surface of the second hard coat layer (the surface opposite to the first hard coat layer side). I can do it. Specifically, the Vickers indenter is preferably within a range of 1.5 μm from the surface opposite to the first hard coat layer side in the cross section of the second hard coat layer.

If the Vickers hardness (N2) of the cross section of the first hard coat layer is less than 250 MPa, the surface hardness of the optical laminate of the present invention may not reach the target pencil hardness of 3H. On the other hand, if the Vickers hardness (N2) exceeds 500 MPa, the Vickers hardness (N2) becomes too hard and brittle, and the cracking property (toughness) may be lowered. Moreover, curl becomes large, and coating and drying may be difficult in the step of laminating the second hard coat.
The more preferable lower limit of the Vickers hardness (N2) is 270 MPa, the more preferable upper limit is 450 MPa, the still more preferable lower limit is 280 MPa, and the still more preferable upper limit is 400 MPa.
The Vickers hardness (N2) is preferably a value measured at a position connecting the midpoints in the thickness direction of the cross section of the first hard coat layer.

Moreover, when the Vickers hardness (N3) of the cross section of the light transmissive substrate (triacetylcellulose substrate) is less than 250 MPa, the surface hardness of the optical laminate of the present invention may not reach the target pencil hardness. . Moreover, during manufacture of the optical laminated body of this invention, since a light-transmitting base material cuts, a wrinkle enters in the flow direction of a light-transmitting base material, or it breaks, it is not preferable. In addition, wrinkles (swells) may enter due to the effect of curing shrinkage of the first hard coat layer. On the other hand, when the Vickers hardness (N3) exceeds 335 MPa, the Vickers hardness (N3) becomes too hard and brittle, and the crack property (toughness) may be lowered. A more preferable lower limit of the Vickers hardness (N3) is 255 MPa, a more preferable upper limit is 330 MPa, a still more preferable lower limit is 260 MPa, and a still more preferable upper limit is 325 MPa.
In addition, it is preferable that the said Vickers hardness (N3) is a value measured in the position which connects the midpoint of the thickness direction of the cross section of the said transparent base material.

Here, as a specific method for measuring the Vickers hardness (N1) of the cross section of the second hard coat layer, for example, as shown in FIG. 1, the above (N1) is the second hard coat layer 10. From the obtained load-displacement curve, a diamond regular triangular pyramid-shaped barkovic indenter 12 having a diagonal angle of 115 ° from the direction perpendicular to the cross-section 10a is pushed into a predetermined position (line AA) of the cross-section 10a. The Vickers hardness is calculated, and the average obtained from the five points is defined as the Vickers hardness (N1) of the second hard coat layer. More specifically, the Vickers hardness is calculated by calculating the surface area A ′ (mm ² ) from the length of the diagonal line of the triangular pyramid-shaped depression 13a formed by indentation of the Berkovich indenter, and the test load F (N) Is obtained by dividing (F / A ').
Further, the Vickers hardness (N2) of the cross section of the first hard coat layer 100 is, as shown in FIG. 1, at the center (BB line) of the cross section 100a of the first hard coat layer 100. On the other hand, the Vickers hardness (average obtained for five locations) is obtained from the depression 13b formed by pushing the Barkovic indenter 12 from the vertical direction. Further, the Vickers hardness (N3) of the cross section of the triacetyl cellulose base material is determined by applying the Barcovic indenter 12 from the direction perpendicular to the cross section 11a at the center (CC line) of the cross section 11a of the light transmissive base material 11. From the depression 13c formed by pressing, the Vickers hardness (average obtained for five locations) is obtained in the same manner as (N1).
The Vickers hardness can be measured by the nanoindentation method using a product name “TI950 TriboIndenter” and an indenter “Berkovich indenter (manufactured by a pyramid)” manufactured by HYSITRON (Heiditron).
Specifically, the measurement of the Vickers hardness is preferably performed by the following method.
(1) Load: The Berkovich indenter 12 is pushed from 0 to 200 nm over 20 seconds (pushing speed: 10 nm / second).
(2) Holding: Holding the depressed Barkovic indenter 12 for 5 seconds (3) Unloading: Returning the Barkovic indenter 12 from 200 nm to 0 nm over 20 seconds (returning speed: 10 nm / second)
(4) The max load measured by the above (1) to (3) is measured, and using the max load (P _max (μN) and the indentation area A (nm ² ) having a depth of 200 nm, P _max / A Calculate Vickers hardness

In the optical layered body of the present invention, the second hard coat layer preferably has a surface pencil hardness test (4.9 N load) hardness of 3H or more. If it is less than 3H, the hard coat property of the optical layered body of the present invention may be insufficient. In addition, the said pencil hardness test is a test according to the pencil hardness test prescribed | regulated to JISK5600-5-4 (1999).
In this specification, the hardness according to the pencil hardness test of the second hard coat layer was scratched at a length of 1/3 or more of the length drawn once, among 5 scratch tests. If NG is NG and NG is 1 or less, it means the result of evaluation based on the criterion of passing. In other words, if the scratch test is performed 5 times and the scratch is generated once, the description is “4/5” and the test is accepted. If the scratch test is performed 5 times and the scratch is generated 4 times, “1/5” is obtained. Will be rejected.

The optical layered body of the present invention is a sample cut to a size of 100 mm × 100 mm square, and when the sample is allowed to stand and curl, the distance between the two opposing sides approached by curling the sample. The (shortest distance) is preferably 10 to 100 mm. When it is less than 10 mm, the occurrence of curling of the optical laminate of the present invention is not sufficiently suppressed, and when it is 100 mm, no curling is generated in the sample.

The optical layered body of the present invention has a conventional optical functional layer (low refractive index layer, high refractive index layer, antifouling layer, An antistatic layer, an antiglare layer, etc.) may be formed. These optical functional layers may be organic materials, inorganic materials, or a mixture of organic materials and inorganic materials, and can be formed by a conventionally known configuration and method. For example, a composition in which hollow silica is mixed with an organic binder is applied and cured, and a low refractive index layer is laminated, or an inorganic thin film such as SiOx (x = 1 to 2) is sputtered or CVD deposited. When one or more functional layers are provided on the second hard coat layer, such as by laminating a low refractive index layer, the indentation hardness of the optical laminate of the present invention by nanoindentation is the second The hardness can be improved to 2 to 3 times higher hardness (upper limit is about 4 GPa) than the case of only the hard coat layer. This is a state in which the hardness of the outermost surface is improved, so that the scratch resistance is very good.

Since the optical layered body of the present invention has the above-described configuration, it can have high hardness and excellent scratch resistance, and curling can be suppressed.
For this reason, the optical layered body of the present invention is used for a flexible type organic EL display, a portable terminal such as a smartphone or a wristwatch type terminal, a display device inside an automobile, a flexible panel used for a wristwatch, etc. It can be suitably used for an image display device such as a device or a touch panel.

It is a schematic diagram explaining the measuring method of Vickers hardness.

The contents of the present invention will be described with reference to the following examples, but the contents of the present invention should not be construed as being limited to these embodiments.

Example 1
A triacetyl cellulose base material (manufactured by FUJIFILM Corporation, TAC25) having a thickness of 25 μm is prepared as a light-transmitting base material, and the composition having the composition shown in Table 1 above is formed on one surface of the light-transmitting base material. One composition A for hard coat layer was applied to form a coating film (penetrating layer and non-penetrating layer).
Next, the solvent in the coating film is evaporated by circulating dry air at 70 ° C. for 45 seconds with respect to the formed coating film, and using an ultraviolet irradiation device (Fusion UV System Japan, light source H bulb), The coating film was half-cured by irradiating ultraviolet rays under a high oxygen concentration atmosphere (oxygen concentration of 500 ppm or more) so that the integrated light amount was 50 mJ / cm ² to form a coating film composed of a permeation layer and a non-penetration layer. .
Next, the second hard coat layer composition 1 having the composition shown in Table 2 was applied onto the half-cured first hard coat layer composition coating to form a coating film. Next, the solvent in the coating film is evaporated by circulating dry air at 70 ° C. for 45 seconds with respect to the formed coating film, and using an ultraviolet irradiation device (Fusion UV System Japan, light source H bulb), A second hard coat layer having a thickness of 4.5 μm (during curing) is obtained by irradiating ultraviolet rays under a nitrogen atmosphere (oxygen concentration of 200 ppm or less) so that the integrated light quantity becomes 200 mJ / cm ² to cure the coating film. And an optical laminate was produced.

(Example 2)
An optical laminate was produced in the same manner as in Example 1 except that the thickness of the second hard coat layer was 6.0 μm.

Example 3
An optical laminate was produced in the same manner as in Example 1 except that the thickness of the second hard coat layer was 2.5 μm.

Example 4
An optical laminate was produced in the same manner as in Example 1 except that the thickness of the osmotic layer of the first hard coat layer was 3.0 μm and the thickness of the non-penetrable layer was 3.0 μm.

(Example 5)
An optical laminate was produced in the same manner as in Example 1 except that the thickness of the osmotic layer of the first hard coat layer was 1.5 μm and the thickness of the non-penetrable layer was 1.5 μm.

(Example 6)
The thickness of the first hard coat layer was 3.0 μm, the thickness of the non-penetrated layer was 3.0 μm, and the thickness of the second hard coat layer was 6.0 μm. An optical laminate was produced in the same manner as in Example 1.

(Example 7)
An optical laminate was produced in the same manner as in Example 1 except that a 40 μm thick triacetyl cellulose substrate (manufactured by Konica Minolta, TAC 40) was used as the light transmissive substrate.

(Example 8)
An optical laminate was produced in the same manner as in Example 1, except that the second hard coat layer composition 2 was used instead of the second hard coat layer composition 1.

Example 9
An optical laminate was produced in the same manner as in Example 1 except that the second hard coat layer composition 3 was used instead of the second hard coat layer composition 1.

(Example 10)
An optical laminate was produced in the same manner as in Example 9 except that a 40 μm thick triacetyl cellulose substrate (manufactured by Konica Minolta, TAC 40) was used as the light transmissive substrate.

(Example 11)
An optical laminate was produced in the same manner as in Example 1, except that the second hard coat layer composition 4 was used instead of the second hard coat layer composition 1.

(Example 12)
An optical laminate was produced in the same manner as in Example 1 except that the second hard coat layer composition 5 was used instead of the second hard coat layer composition 1.

(Example 13)
An optical laminate was produced in the same manner as in Example 1 except that the second hard coat layer composition 6 was used instead of the second hard coat layer composition 1.

(Example 14)
An optical laminate was produced in the same manner as in Example 1, except that the second hard coat layer composition 7 was used instead of the second hard coat layer composition 1.

(Example 15)
An optical laminate was produced in the same manner as in Example 1 except that the second hard coat layer composition 8 was used instead of the second hard coat layer composition 1.

(Example 16)
An optical laminate was produced in the same manner as in Example 1 except that the first hard coat layer composition B was used in place of the first hard coat layer composition A.

(Example 17)
An optical laminate was produced in the same manner as in Example 1, except that the first hard coat layer composition C was used instead of the first hard coat layer composition A.

(Example 18)
An optical laminate was produced in the same manner as in Example 1 except that the first hard coat layer composition D was used instead of the first hard coat layer composition A.

(Example 19)
An optical laminate was produced in the same manner as in Example 1 except that the first hard coat layer composition E was used instead of the first hard coat layer composition A.

(Example 20)
Instead of the first hard coat layer composition A, the first hard coat layer composition F was used so that the thickness of the permeation layer was 1.6 μm and the thickness of the non-penetration layer was 2.6 μm. Except for the above, an optical laminate was produced in the same manner as in Example 1.

(Example 21)
Instead of the first hard coat layer composition A, the first hard coat layer composition G was used so that the thickness of the permeation layer was 3.0 μm and the thickness of the non-penetration layer was 1.2 μm. Except for the above, an optical laminate was produced in the same manner as in Example 1.

(Example 22)
Instead of the first hard coat layer composition A, the first hard coat layer composition H was used so that the thickness of the permeation layer was 1.2 μm and the thickness of the non-penetration layer was 3.0 μm. Except for the above, an optical laminate was produced in the same manner as in Example 1.

(Example 23)
Instead of the first hard coat layer composition A, the first hard coat layer composition I was used so that the thickness of the permeation layer was 1.2 μm and the thickness of the non-penetration layer was 3.0 μm. Except for the above, an optical laminate was produced in the same manner as in Example 1.

(Example 24)
An optical laminate was produced in the same manner as in Example 1 except that the first hard coat layer composition J was used instead of the first hard coat layer composition A.

(Example 25)
An optical laminate was produced in the same manner as in Example 1 except that the first hard coat layer composition K was used in place of the first hard coat layer composition A.

(Example 26)
An optical laminate was produced in the same manner as in Example 1 except that the first hard coat layer composition L was used instead of the first hard coat layer composition A.

(Example 27)
An optical laminate was produced in the same manner as in Example 1, except that the first hard coat layer composition M was used instead of the first hard coat layer composition A.

(Example 28)
Instead of the first hard coat layer composition A, the first hard coat layer composition C was used, and instead of the second hard coat layer composition 1, the second hard coat layer composition. An optical laminate was produced in the same manner as in Example 1 except that 3 was used.

(Comparative Example 1)
An optical laminate was produced in the same manner as in Example 1 except that the second hard coat layer was not formed.

(Comparative Example 2)
Instead of the first hard coat layer composition A, the first hard coat layer composition N is used, the first hard coat layer has a non-penetrable layer and a non-penetrable layer has a thickness of 4.0 μm. An optical laminate was produced in the same manner as in Example 1 except that was formed.

(Comparative Example 3)
In place of the first hard coat layer composition A, the first hard coat layer composition O is used, a non-penetrating layer is not formed, and the thickness of the penetrating layer is 4.0 μm. An optical laminate was produced in the same manner as in Example 1 except that was formed.

(Comparative Example 4)
An optical laminate was produced in the same manner as in Example 1 except that the first hard coat layer composition P was used instead of the first hard coat layer composition A.

(Comparative Example 5)
An optical laminate was produced in the same manner as in Example 1 except that the second hard coat layer composition 9 was used instead of the second hard coat layer composition 1.

(Reference Example 1)
An optical laminate was manufactured in the same manner as in Example 1 except that the thickness of the second hard coat layer was 10.0 μm.

(Reference Example 2)
An optical laminate was produced in the same manner as in Example 1 except that the thickness of the second hard coat layer was 1.0 μm.

(Reference Example 3)
An optical laminate was produced in the same manner as in Example 1 except that the first hard coat layer composition Q was used in place of the first hard coat layer composition A.

(Reference Example 4)
An optical laminate was produced in the same manner as in Example 1 except that the second hard coat layer composition 10 was used instead of the second hard coat layer composition 1.

The optical laminates obtained in Examples, Comparative Examples and Reference Examples were evaluated as follows, and the results are shown in Table 3.

(Measurement of Vickers hardness)
The cross section of the first hard coat layer, the cross section of the second hard coat layer, and the cross section of the light-transmitting substrate of the optical laminates according to Examples, Comparative Examples, and Reference Examples are subjected to Vickers hardness by a nanoindentation method. The measured values were designated as N1, N2, and N3, respectively.
In addition, the optical laminated body which concerns on each Example, a comparative example, and a reference example is cut | judged to 50 micrometers, the place which becomes 0.5 micrometer from the side opposite to the 1st hard-coat layer side of the cross section of a 2nd hard-coat layer, and The Vickers hardness was measured by the following method at a location which is approximately the center of the cross section of each of the first hard coat layer and the light transmissive substrate. The average value of the values measured five times was defined as N1, N2, and N3, respectively.
In addition, the detailed measuring method of Vickers hardness is as having demonstrated using FIG.
A specific method for measuring Vickers hardness by the nanoindentation method was performed using “TI950 TriboIndenter” manufactured by HYSITRON. That is, after the Berkovich indenter (triangular pyramid) was pushed in by 200 nm from the cross section of the second hard coat layer and the like of the optical laminates according to Examples, Comparative Examples, and Reference Examples, the residual stress was relaxed by holding constant, Unload and measure the max load after relaxation, and calculate the indentation hardness by P _max / A using the max load (P _max (μN) and the indentation area A (nm ² ) of depth 200 nm) The measurement temperature is 25 ° C. and the measurement humidity is 50%.
(Berkovic indenter displacement control system)
Load (indentation) from 0 nm to 200 nm in 20 seconds
Hold at 200 nm for 5 seconds Unload from 200 nm to 0 nm in 20 seconds

(SW resistance)
The surface of the second hard coat layer of the optical laminates according to Examples, Comparative Examples and Reference Examples was changed using a steel wool ("Bonster # 0000 (trade name)", manufactured by Nippon Steel Wool Co., Ltd.), and the friction load was changed. The film was rubbed back and forth 10 times, and then the presence or absence of scratches or peeling of the coating film was visually observed and evaluated according to the following criteria.
○: No damage at 700 g / cm ² load, no peeling of coating film ×: There was a scratch or peeling of coating film at 700 g / cm ² load

(Haze)
The hazes of the optical laminates according to Examples, Comparative Examples, and Reference Examples were measured according to JIS K7361 using a haze meter (manufactured by Murakami Color Research Laboratory, product number: HM-150).

(Pencil hardness)
The pencil hardness of the optical laminates according to Examples, Comparative Examples, and Reference Examples was measured based on JIS K5600-5-4 (1999).

(Adhesion)
Cross cut cross cut test was performed on optical laminates according to Examples, Comparative Examples, and Reference Examples, and the cut remaining on the light-transmitting substrate after peeling off the tape (manufactured by Nichiban Co.) with respect to the original number of cut parts (100) The number of copies was evaluated according to the following criteria.
○: 90-100
X: 0 to 89

(Interference fringes)
A black tape for preventing back surface reflection is pasted on the surface opposite to the surface on which the first and second hard coat layers of the light transmissive substrate of the optical laminates according to Examples, Comparative Examples and Reference Examples are formed. The optical laminate was visually observed from the surface of the second hard coat layer, and the presence or absence of occurrence of interference fringes was evaluated.
Those where no interference fringes were observed were marked with “◯”, and those where interference fringes were observed were marked with “x”.

(curl)
The optical laminates according to Examples, Comparative Examples, and Reference Examples were cut into 100 mm × 100 mm squares in any direction and allowed to stand for 24 hours in an atmosphere at a temperature of 25 ° C. and a humidity of 50%. Thereafter, the distance (curl) between the two opposite sides that floated was measured. When two opposing sides overlap each other, it is described as “tubular”.

(Area ratio)
About the optical laminated body which concerns on an Example, a comparative example, and a reference example, from the cross-sectional photograph of the 2nd hard-coat layer by TEM, binarization (1st) of image analysis software Win Roof (Mitani Corporation visual system part) The area of the region of 0.01 μm 2 or more was measured.

As shown in Table 3, none of the optical laminates according to the examples had a pencil hardness of 3H or higher, excellent SW resistance evaluation, and no curls were cylindrical. In addition, the optical laminated body which concerns on any Example forms the sea island structure in which the 1st resin component of the composition for 1st hard-coat layers eluted in the 1st hard-coat layer of the 2nd hard-coat layer The area ratio of the first resin component was in the range of 5 to 15%.
The optical laminate according to Comparative Example 1 was inferior in each evaluation of pencil hardness and SW resistance because the second hard coat layer was not provided. Since the optical laminate according to Comparative Example 2 did not have a permeable layer formed in the first hard coat layer, the optical laminate according to Comparative Example 3 had a non-permeable layer formed in the first hard coat layer. Therefore, the adhesion between the first hard coat layer and the second hard coat layer was inferior, and interference fringes were also generated. The optical laminate according to Comparative Example 3 was inferior in pencil hardness. Since the optical laminate according to Comparative Example 4 did not contain the first silica fine particles in the first hard coat layer, the optical laminate according to Comparative Example 5 had the second silica in the second hard coat layer. Since the fine particles were not included, the evaluation of interference fringes was inferior, and a large curl was generated to form a cylinder.
In the optical layered body according to Reference Example 1, the thickness of the second hard coat layer was too thick, 10.0 μm. In the optical layered body according to Reference Example 2, the thickness of the second hard coat layer was as thin as 1.0 μm, and the pencil hardness result was 2H, which was inferior to the pencil hardness result of the optical layered body according to the example. Since the optical laminate according to Reference Example 3 did not contain a thermoplastic resin in the first hard coat layer composition, the adhesiveness between the first hard coat layer and the second hard coat layer was inferior. Interference fringes were also generated. In the optical layered body according to Reference Example 4, the first hard coat layer composition eluted in the second hard coat layer has too much first resin component (the area ratio of the first resin component is 15%). Therefore, the haze was high and the SW resistance was inferior.

Since the optical layered body of the present invention has the first hard coat layer and the second hard coat layer having the above-described configuration on a light-transmitting substrate, it has high hardness and excellent scratch resistance, Is suppressed.
Therefore, the optical laminate of the present invention is preferably applied to a cathode ray tube display (CRT), a liquid crystal display (LCD), a plasma display (PDP), an electroluminescence display (ELD), a field emission display (FED), and the like. Can do.

10 Second hard coat layer 10a Cross section 11 of second hard coat layer 10 Light transmissive substrate 11a Cross section 12 of light transmissive substrate 11 Barkovic indenters 13a, 13b, 13c Indentation 100 First hard coat layer 100a First Cross section of one hard coat layer 100

Claims (5)

A first hard coat layer is formed on one surface of the light transmissive substrate, and a second hard coat layer is formed on the side surface of the first hard coat layer opposite to the light transmissive substrate side. An optical laminate formed,
The first hard coat layer is formed using a first hard coat layer composition containing first silica fine particles and a first resin component, and the first resin component is the It has a permeation layer formed by penetrating into a light transmissive substrate, and a non-penetration layer formed by the first hard coat layer composition,
The second hard coat layer is formed using a second hard coat layer composition containing second silica fine particles and a second resin component, and the first resin component is a sea island. An optical laminate comprising a dispersion dispersed in a shape. The optical laminate according to claim 1, wherein the first resin component dispersed in a sea-island shape is contained unevenly on the first hard coat layer side of the second hard coat layer. The Vickers hardness (N1) of the cross section of the second hard coat layer, the Vickers hardness (N2) of the cross section of the non-penetrable layer of the first hard coat layer, and the Vickers hardness (N3) of the cross section of the light transmissive substrate, respectively. When measured at a load of 10 mN by the nanoindentation method,
The Vickers hardness (N1) is 600 to 1300 MPa,
The Vickers hardness (N2) is 250 to 500 MPa,
The optical laminated body according to claim 1 or 2, wherein the Vickers hardness (N3) is 250 to 335 MPa. The thickness of the first hard coat layer is 2 to 7 µm, the thickness of the second hard coat layer is 2 to 7 µm, and the thickness of the light-transmitting substrate is 15 to 45 µm. The optical laminated body as described. The optical laminate according to claim 1, 2, 3, or 4, wherein the first resin component is a thermoplastic resin.

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