JP5096069B2 - Optical laminate, polarizing plate, and image display device - Google Patents

Description

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

In an image display device such as a cathode ray tube display device (CRT), a liquid crystal display (LCD), a plasma display (PDP), and an electroluminescence display (ELD), an optical laminate for preventing reflection is generally provided on the outermost surface. ing. Such an anti-reflection optical laminate suppresses image reflection or reduces reflectance by scattering or interference of light.

As one of such an antireflection optical laminate, an antiglare laminate in which an antiglare layer having an uneven shape is formed on the surface of a transparent substrate is known. Such an antiglare laminate can prevent external light from being scattered due to the uneven shape of the surface and prevent deterioration of visibility due to reflection of external light or image reflection. As an anti-glare laminated body, what formed the unevenness | corrugation with the particle | grains (patent document 1), and what made the uneven | corrugated shape by giving an emboss shaping process are known (patent document 2, 3).

When such an antiglare laminate is used on the surface of an image display device, the surface irregularity shape plays the role of a fine lens, so when transmitted light passes through the irregular surface of the antiglare laminate, the display There is also a problem that a state of “glaring” is likely to occur that disturbs the pixels and the like.

As a method of eliminating this “glare”, anti-glare properties can be obtained by increasing the surface roughness for the purpose of enhancing the sharpness, or by adding internal scattering particles having a refractive index difference from the resin forming the anti-glare layer. Techniques such as imparting an internal scattering effect to a laminate are known.

However, when the internal scattering particles as described above are blended, the black luminance is lowered, and as a result, there is a possibility that the problem of a reduction in contrast occurs. For this reason, development of the optical laminated body which can make the moderate internal scattering effect for eliminating glare and the outstanding contrast compatible is desired.

JP-A-6-18706 Japanese Patent Laid-Open No. 6-16851 JP 2004-341070 A

An object of the present invention is to provide an optical laminate that has both good contrast and antiglare effect while maintaining good antiglare properties.

The present invention is an optical laminate having a light transmissive substrate and an internal scattering layer containing the internal scattering particles provided on the light transmissive substrate, the internal scattering particles having an average particle size Is 1 to 10 μm, contains a particle matrix component made of an organic resin having a refractive index of 1.50 or more, and has a refractive index of 1 made of an organic material and / or an inorganic material having an average particle size of 5 to 300 nm. .55 or more of fine particles are included, and the internal scattering layer has the internal scattering particles dispersed in a matrix resin, and the refractive index of the fine particles included in the internal scattering particles is expressed as n _A. n _B the refractive index of the encapsulated ingredients other than fine particles _and the refractive index of the matrix resin and n _C, n a, n _B, and n _C is the optical stack and satisfies the following formula (1) About the body.
n _C <n _B <n _A (1)

Upper SL internal scattering particles preferably volume fraction of the encapsulated microparticle {= (volume of total volume / internal scattering particles are contained fine particles) × 100} is 30% or less.
The fine particles encapsulated in the internal scattering particles preferably have a refractive index of 1.55 or more and contain at least one selected from the group consisting of titanium oxide, zinc oxide, zirconia and alumina.
Upper SL internal scattering particles may further have an outer shell adhered particles having an average particle diameter was less physical adsorption 1μm in the outer portion.

The optical laminate is suitably used as an antireflection laminate.
The present invention is also a self-luminous image display device including the above-described optical laminate.
This invention is a polarizing plate provided with a polarizing element, Comprising: The polarizing plate characterized by providing the above-mentioned optical laminated body on the surface of the said polarizing element.
The present invention also provides a non-self-luminous image display device comprising the above-described optical laminate or the above-described polarizing plate on a surface.
The present invention is described in detail below.

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

Internal scattering layer The optical layered body of the present invention has a light-transmitting substrate and an internal scattering layer containing internal scattering particles provided on the light-transmitting substrate.
The internal scattering particles contained in the internal scattering layer are fine particles made of an organic material and / or an inorganic material having a lower limit of the average particle diameter of 1 μm and an upper limit of 10 μm, and a lower limit of the average particle diameter of 5 nm and an upper limit of 300 nm. (Hereinafter also referred to as encapsulated fine particles). The optical layered body of the present invention has excellent contrast and internal scattering effect by containing the internal scattering particles.
By including such internal scattering particles, the effect of having both excellent contrast and internal scattering effect is obtained because of the refractive index of the internal scattering particles composed of the particle matrix component enclosing the above-mentioned internal fine particles, and the internal scattering Since the difference from the refractive index of the internal scattering layer made of a matrix resin, which will be described later, enveloping the particles can be reduced, it is assumed that multiple scattering between the internal scattering particles can be suppressed and the C / R reduction can be prevented. Is done. However, with this alone, the difference in refractive index between the internal scattering particles and the matrix resin of the internal scattering layer is small, and sufficient internal scattering properties cannot be obtained. Therefore, in addition to the above, it is presumed that a desired internal scattering property can be obtained by encapsulating a plurality of dispersed internal scattering particles whose refractive index is controlled in the internal scattering layer.

The shape of the internal scattering particles is not particularly limited, and examples thereof include a spherical shape, a spheroid shape, a thin plate shape, and a needle shape. When the average particle diameter of the internal scattering particles is spherical, the lower limit is 1 μm and the upper limit is 10 μm. When the shape is other than spherical, the lower limit of the maximum length is 1 μm and the upper limit is 10 μm.
When the average particle size of the internal scattering particles is less than 1 μm, the contrast of the image display device using the optical laminate of the present invention is lowered, and a sufficient glare prevention effect cannot be obtained. When the average particle diameter of the internal scattering particles exceeds 10 μm, the film thickness of the optical layered body of the present invention is required to be larger than the particle diameter, and the occurrence of cracks due to the increase in film thickness becomes remarkable. In addition, the said average particle diameter can be measured from SEM and TEM observation.
The internal scattering particles may be aggregated particles. In the case of the aggregated particles, the secondary particle size is preferably within the above range. The average particle size represents the average particle size of monodispersed particles (particles having a single shape), and if the particles are irregular shaped particles having a broad particle size distribution, The particle diameter of the most abundant particles is expressed as an average particle diameter.

The internal scattering particles include a large number of fine particles (encapsulated fine particles) made of an organic material or an inorganic material whose lower limit of the average particle diameter is 5 nm and whose upper limit is 300 nm.
The shape of the encapsulated fine particles is not particularly limited, and examples thereof include a spherical shape, a spheroid shape, a thin plate shape, and a needle shape. When the average particle diameter of the encapsulated fine particles is spherical, the lower limit is 5 nm and the upper limit is 300 nm. When the shape of the encapsulated fine particles is other than spherical, the lower limit of the maximum length is 5 nm and the upper limit is 300 nm.
If the average particle size of the encapsulated fine particles is less than 5 nm, desired internal scattering cannot be obtained, and thus no effect of improving glare can be obtained. If the average particle size exceeds 300 nm, C / R reduction cannot be sufficiently suppressed. A preferable lower limit of 20 nm and a preferable upper limit of the average particle diameter of the encapsulated particles are 150 nm. In addition, the said average particle diameter can be measured from SEM and TEM observation. When the encapsulated fine particles in the internal scattering layer are other than spherical, the maximum length can be measured by, for example, observing a cross section of the internal scattering layer at an arbitrary position with SEM and TEM, and at least 10 A method of measuring the maximum length of the individual encapsulated fine particles and calculating an average value thereof can be mentioned.
The encapsulated fine particles may be aggregated particles. In the case of aggregated particles, the secondary particle size is preferably within the above range. The average particle size represents the average particle size of monodispersed particles (particles having a single shape), and if the particles are irregular shaped particles having a broad particle size distribution, The particle diameter of the most abundant particles is expressed as an average particle diameter.

The internal scattering particles contain encapsulated fine particles.
Here, “encapsulating encapsulated fine particles” means a state in which a plurality of encapsulated fine particles made of an organic material and / or an inorganic material different from the particle matrix component constituting the internal scattering particles are dispersed, preferably This means that a plurality of encapsulated fine particles are contained in the internal scattering particles within a range that satisfies the volume fraction of the encapsulated fine particles in the internal scattering particles described later.

FIG. 1 is a cross-sectional view schematically showing an example of the internal scattering particles.
As shown in FIG. 1, the internal scattering particles 10 are preferably in a state where the encapsulated fine particles 11 are dispersed in a particle matrix component 12 made of an organic resin, and the encapsulated fine particles 11 are formed on the surface of the internal scattering particles 10. Preferably it is not exposed.
However, the encapsulated fine particles may be exposed on the surface of the internal scattering particles. In this case, it is preferable that the surface area of the exposed internal fine particles is 20% or less of the surface area of the internal scattering particles. If it exceeds 20%, an internal scattering layer having both excellent contrast and internal scattering effect may not be obtained.

The internal scattering particles preferably have a volume fraction {= (total volume of internal particles / volume of internal scattering particles) × 100} of the internal microparticles of 30% or less. If it exceeds 30%, C / R reduction may not be sufficiently suppressed. A preferable lower limit of the volume fraction is 1%. If it is less than 1%, suitable internal scattering may not be obtained.

The encapsulated fine particles are made of an organic material and / or an inorganic material. In particular, when the encapsulated fine particles are made of an inorganic material, it is preferable in that it has a particularly excellent C / R reduction suppressing effect.
It does not specifically limit as said organic material, For example, various organic resins, such as transparent styrene resin, can be used.
The refractive index of the organic material is preferably 1.55 or more. When the refractive index is less than 1.55, as described later, the matrix resin of the internal scattering layer in which the preferable range of the refractive index is 1.45 to 1.65, and the preferable range of the refractive index is 1.50 or more. The difference in refractive index between the internal scattering particles and the particle matrix component becomes small, and there is a fear that desired internal scattering properties cannot be obtained.

In addition, the inorganic material is not particularly limited, and examples thereof include a material having a high refractive index expression such as titanium oxide, zinc oxide, zirconia, and alumina. These inorganic materials may be used independently and 2 or more types may be used together. Especially, it is preferable that it contains at least 1 type selected from the group which consists of a titanium oxide, a zinc oxide, a zirconia, and an alumina.

When the encapsulated fine particles contain at least one selected from the group consisting of titanium oxide, zinc oxide, zirconia and alumina, the encapsulated particles preferably have a refractive index of 1.55 or more. When the refractive index is less than 1.55, as described later, the matrix resin of the internal scattering layer in which the preferable range of the refractive index is 1.45 to 1.65, and the preferable range of the refractive index is 1.50 or more. The difference in refractive index between the internal scattering particles and the particle matrix component becomes small, and there is a fear that desired internal scattering properties cannot be obtained.

The internal scattering particles preferably contain a particle matrix component made of an organic resin having a refractive index of 1.50 or more. The particle matrix component serves as a main raw material for the internal scattering particles, and functions as a binder component for dispersing the encapsulated fine particles. If the refractive index is less than 1.50, as will be described later, the preferred range of the refractive index of the matrix resin of the internal scattering layer is 1.45 to 1.65, so there is a risk of C / R reduction.
The organic resin is not particularly limited as long as the refractive index is 1.50 or more. For example, a copolymer of a styrene resin, an isocyanate compound, an ester compound, an acrylic monomer component, or a monomer copolymerizable therewith. Etc.
Examples of the copolymer of the acrylic monomer component and a monomer copolymerizable therewith include, for example, methyl methacrylate-styrene copolymer.

Furthermore, the internal scattering particles may be in a state where the encapsulated fine particles made of an organic material and / or an inorganic material and the particle matrix component are chemically bonded.

The method for producing the internal scattering particles is not particularly limited, and examples thereof include a method of obtaining a particle matrix component by performing the above-described polymerization reaction of the organic resin in a liquid medium in which the encapsulated fine particles are dispersed. In the production of the internal scattering particles, a dispersant may be used in combination. Moreover, in order to obtain the internal scattering particles having a particle diameter in a predetermined range, the production of the internal scattering particles may be performed while being dispersed by, for example, a bead mill disperser.

The internal scattering particles preferably further have physically adsorbed outer adhered particles having an average particle diameter of 1 μm or less in the outer portion. By having the outer-attached particles, desired internal scattering properties can be further imparted.

The shape of the outer-attached particles is not particularly limited, and examples thereof include a spherical shape, a spheroid shape, a thin plate shape, and a needle shape. When the average particle diameter of the outer shell-attached particles is spherical, the upper limit is 1 μm. When the shape is other than spherical, the upper limit of the maximum length is 1 μm. When the average particle diameter of the outer-attached particles exceeds 1 μm, the internal scattering particles become close to the aggregated state, and multiple scattering is likely to occur, so C / R may be lowered. A preferable upper limit is 0.4 μm. In addition, the average particle diameter of the outer-attached particles can be measured by the same method as described above.

The outer adhered particles are physically adsorbed on the outer portion of the internal scattering particles, and the amount of adsorption is not particularly limited, but a preferred lower limit is 2 parts by volume and a preferred upper limit with respect to 100 parts by volume of the inner scattering particles. Is 75 parts by volume. In this range, the externally adhered particles are physically adsorbed on the outer part of the internal scattering particles, so that the internal scattering properties can be further improved in addition to the effect of the internal scattering particles including the encapsulated fine particles, thereby reducing the amount of internal scattering particles. Can do.

The raw material for the outer-attached particles is not particularly limited, and examples thereof include styrene resins, isocyanate compounds, ester compounds, copolymers of acrylic monomer components, or copolymers with monomers copolymerizable therewith.
Examples of the copolymer of the acrylic monomer component and a monomer copolymerizable therewith include, for example, methyl methacrylate-styrene copolymer. Of these, aromatic isocyanate or methyl methacrylate-styrene copolymer is preferably used.

A preferable lower limit of the refractive index of the outer adhered particles is 1.50. If it is less than 1.50, as will be described later, since the preferred range of the refractive index of the matrix resin of the internal scattering layer is 1.45 to 1.65, there is a risk of C / R reduction.

The method of physically adsorbing the outer particles attached to the outer part of the inner scattering particles is not particularly limited, and examples thereof include a method of physically causing the child particles (outer particles) to collide with the mother particles (encapsulated fine particles). It is done. In particular, the hybridization system manufactured by Nara Machinery Co., Ltd. can form an order mixture in which the mother particles are coated with the child particles by a dry system that allows the joining of fine powders.

In the internal scattering layer, it is preferable that the internal scattering particles are dispersed in a matrix resin.
The matrix resin functions as a binder resin for the internal scattering layer. It does not specifically limit as said matrix resin, It is preferable to contain resin which has hardening reactivity. The resin having the curing reactivity is not particularly limited. For example, an ionizing radiation curable resin, an ionizing radiation curable resin and a solvent-drying resin that are cured by ultraviolet rays or an electron beam (adjust solid content at the time of coating) In order to achieve this, only by drying the added solvent, a mixture with a resin that becomes a film) or a thermosetting resin is exemplified, and an ionizing radiation curable resin is preferably used.
Moreover, according to the preferable aspect of this invention, ionizing radiation curable resin and solvent dry resin are included at least.

Examples of the ionizing radiation curable resin include compounds having one or more unsaturated bonds such as a compound having an acrylate functional group.
Examples of the compound having 1 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, and pentaerythritol tris. Reaction products such as (meth) acrylates, polyfunctional compounds such as dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate and (meth) allyllate ( For example, poly (meth) acrylate ester of polyhydric alcohol). In the present specification, “(meth) acrylate” refers to methacrylate and acrylate.

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

When the ionizing radiation curable resin is used as an ultraviolet curable resin, it is preferable to use a photopolymerization initiator.
Specific examples of the photopolymerization initiator include, for example, acetophenones, benzophenones, Michler benzoyl benzoate, α-amino oxime esters, thioxanthones, propiophenones, benzyls, benzoins, and acylphosphine oxides. It is done.
In addition, it is preferable to use a mixture of photosensitizers, and specific examples thereof include n-butylamine, triethylamine, poly-n-butylphosphine, and the like.

As the photopolymerization initiator, in the case of a resin system having a radical polymerizable unsaturated group, for example, acetophenones, benzophenones, thioxanthones, benzoin, benzoin methyl ether and the like are preferably used alone or in combination.
In addition, as the photopolymerization initiator, in the case of a resin system having a cationic polymerizable functional group, for example, an aromatic diazonium salt, an aromatic sulfonium salt, an aromatic iodonium salt, a metallocene compound, a benzoin sulfonate ester, etc. Or it is preferable to use as a mixture.

As the addition amount of the photopolymerization initiator, a preferable lower limit is 0.1 parts by mass and a preferable upper limit is 10 parts by mass with respect to 100 parts by mass of the ionizing radiation curable composition.

The solvent-drying resin used by mixing with the ionizing radiation curable resin mainly includes thermoplastic resins.
As the thermoplastic resin, those generally exemplified are used. By adding the solvent-drying resin, coating film defects on the coated surface can be effectively prevented. Specific examples of preferred thermoplastic resins include those generally exemplified. For example, styrene resins, (meth) acrylic resins, vinyl acetate resins, vinyl ether resins, halogen-containing resins, fats Examples thereof include cyclic olefin resins, polycarbonate resins, polyester resins, polyamide resins, cellulose derivatives, silicone resins, and rubbers or elastomers.

Further, as the thermoplastic resin, it is usually preferable to use a resin that is non-crystalline and is soluble in an organic solvent (in particular, a common solvent capable of dissolving a plurality of polymers and curable compounds). In particular, resins with high moldability or film formability, transparency and weather resistance, such as styrene resins, (meth) acrylic resins, alicyclic olefin resins, polyester resins, cellulose derivatives (cellulose esters, etc.) Etc. are preferred.

According to a preferred aspect of the present invention, when the material of the light-transmitting substrate is a cellulose resin such as triacetyl cellulose “TAC”, preferable specific examples of the thermoplastic resin include, for example, nitrocellulose, acetyl cellulose, Examples thereof include cellulose resins such as cellulose acetate propionate and ethyl hydroxyethyl cellulose. By using the cellulose resin, the adhesion and transparency between the light transmissive substrate and the internal scattering layer can be improved.

Examples of the thermosetting resin that can be used as the resin having curing reactivity include, for example, phenol resin, urea resin, diallyl phthalate resin, melanin resin, guanamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin, aminoalkyd resin, Examples include melamine-urea cocondensation resin, silicon resin, polysiloxane resin, and the like.
Moreover, when using the said thermosetting resin, hardening agents, such as a crosslinking agent and a polymerization initiator, a polymerization accelerator, a solvent, a viscosity modifier, etc. can also be used together as needed.

In particular, the resin having curing reactivity described above preferably contains three or more curing reactive groups in one molecule. It is preferable that the resin having the curing reactivity contains 3 or more curing reactive groups in one molecule, so that in addition to the dispersibility of the internal scattering particles, the adhesion to the substrate can be maintained. .

In the internal scattering layer containing the internal scattering particles and a cured product obtained by curing a resin having curing reactivity, the refractive index of the inclusion particles is n _A , and components other than the inclusion particles of the inclusion particles (the particle matrix described above) the refractive index of the component) _{n B,} and the refractive index of the matrix resin and _{n C, n a, n B,} and _{n C} preferably satisfies the following formula (1).
n _C <n _B <n _A (1)
By satisfying the formula (1), it is possible to maintain the refractive index difference between the inside of the encapsulated fine particles and the resin having curing reactivity, and as a result, it is excellent in suppressing interface reflection while exhibiting high light scattering properties. Contrast can also be obtained.
In the case where the encapsulated fine particles are made of a plurality of raw materials, the refractive index n _A is an average value of the refractive indexes of the respective encapsulated fine particles.

The refractive index _{n C} of the matrix resin is not particularly limited, for example, is preferably in the range of 1.45 to 1.65. By being in the above range, the refractive index difference from the light-transmitting substrate becomes small, which is preferable.
When the matrix resin is a mixture containing a plurality of resins, the refractive index n _{C of the} matrix resin made of such a mixture is a value calculated by the following method.
That is, a sample film of a matrix resin containing the above internal scattering particles is prepared, the sample film is cut obliquely, and molecules of components other than the internal scattering particles are detected using TOF-SIMS manufactured by ULVAC-PHI. The refractive index of the detected molecule is calculated with reference to a molecular refractive index list disclosed by a Seishin company or Polymer Handbook (John Wiley & Sons).

Here, a method for measuring the refractive index n _A of the encapsulated fine particles and the refractive index n _B of components other than the encapsulated particles of the encapsulated fine particles (the particle matrix component described above) will be described.
A sample film containing the above internal scattering particles is prepared, the sample film is obliquely cut, and the internal fine particles of the internal scattering particles and molecules of components other than the internal fine particles are detected using TOF-SIMS manufactured by ULVAC-PHI. The refractive index of the detected molecule is calculated with reference to a molecular refractive index list disclosed by a Seishin company or Polymer Handbook (John Wiley & Sons). For example, polystyrene is 1.59 and methyl methacrylate resin is 1.49. The methyl methacrylate-styrene copolymer was calculated from each refractive index by detecting the composition of methyl methacrylate and styrene by TOF-SIMS. Further, the molecular structure and composition of the inorganic materials such as titanium oxide, zirconium oxide, alumina, and zinc oxide were similarly detected, and the refractive index was calculated.

The internal scattering layer can be formed by applying the composition for forming an internal scattering layer obtained by mixing the internal scattering particles and the matrix resin in an appropriate solvent to the light transmissive substrate.
The solvent can be selected and used according to the type and solubility of the matrix resin, and at least solid content (a plurality of polymers and resin precursors having curing reactivity, polymerization initiators, other additives) is uniform. Any solvent can be used as long as it can be dissolved in water. Examples of such solvents include ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), ethers (dioxane, tetrahydrofuran, etc.), aliphatic hydrocarbons (hexane, etc.), alicyclic hydrocarbons ( Cyclohexane, etc.), aromatic hydrocarbons (toluene, xylene, etc.), halogenated carbons (dichloromethane, dichloroethane, etc.), esters (methyl acetate, ethyl acetate, butyl acetate, etc.), water, alcohols (ethanol, isopropanol, Butanol, cyclohexanol, etc.), cellosolves (methyl cellosolve, ethyl cellosolve, etc.), cellosolve acetates, sulfoxides (dimethylsulfoxide, etc.), amides (dimethylformamide, dimethylacetamide, etc.), propylene glycol Bruno ethyl ether (PGME), and the like, may be a mixed solvent.

Moreover, the permeable solvent to a light transmissive base material can also be used preferably. By using the permeable solvent, the generation of interference fringes can be prevented, so that a more preferable optical laminate can be obtained.

For example, when the light-transmitting substrate is TAC, specific examples of the permeable solvent include ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isobutyl ketone, diacetone alcohol; methyl formate, methyl acetate, acetic acid Esters such as ethyl, butyl acetate and ethyl lactate; nitrogen-containing compounds such as nitromethane, acetonitrile, N-methylpyrrolidone and N, N-dimethylformamide; glycols such as methyl glycol and methyl glycol acetate; tetrahydrofuran, 1,4- Ethers such as dioxane, dioxolane and diisopropyl ether; halogenated hydrocarbons such as methylene chloride, chloroform and tetrachloroethane; glycosyl such as methyl cellosolve, ethyl cellosolve, butyl cellosolve and cellosolve acetate Ethers and the like; dimethyl sulfoxide and propylene carbonate. These may be used independently and 2 or more types may be used together. Preferably, esters and ketones such as methyl acetate, ethyl acetate, butyl acetate, and methyl ethyl ketone are used. In addition, alcohols such as methanol, ethanol, isopropyl alcohol, butanol, and isobutyl alcohol, and aromatic hydrocarbons such as toluene and xylene can be mixed with the permeable solvent.

As the composition for forming the internal scattering layer, a composition to which a leveling agent such as fluorine or silicone is added is preferable. The composition for forming an internal scattering layer to which a leveling agent is added can impart slipperiness and antifouling properties to the coating film surface during coating or drying, and can impart an effect of scratch resistance. .
As the leveling agent, a light-transmitting substrate is suitably used for a film-like material (for example, triacetyl cellulose) that requires heat resistance.

The internal scattering layer-forming composition includes a resin, a dispersant, a surfactant, an antistatic agent, depending on purposes such as increasing the hardness of the internal scattering layer, suppressing curing shrinkage, and controlling the refractive index. Silane coupling agent, thickener, anti-coloring agent, coloring agent (pigment, dye), antifoaming agent, leveling agent, flame retardant, UV absorber, adhesion-imparting agent, polymerization inhibitor, antioxidant, surface modification An agent or the like may be added.

The internal scattering layer contains the internal scattering particles, but may contain other anti-glare fine particles as long as the contrast is not significantly reduced. The average particle size of the other anti-glare fine particles is not particularly limited, but generally may be about 0.01 to 20 μm. In addition, the shape of the other anti-glare fine particles may be any of a spherical shape, an elliptical shape, and the like, and preferably a spherical shape.
In addition, the average particle diameter of said other anti-glare particle | grains can be measured by the above-mentioned method.

The other anti-glare fine particles exhibit anti-glare properties, and inorganic and organic particles can be used, and preferably transparent.
Specific examples of other anti-glare fine particles formed of an organic material include plastic beads. Specific examples of the plastic beads include, for example, styrene beads (refractive index 1.60), melamine beads (refractive index 1.57), acrylic beads (refractive index 1.49 to 1.53), acrylic styrene beads ( Examples thereof include refractive index 1.54), benzoguanamine-formaldehyde condensate (refractive index 1.68), melamine-formaldehyde condensate (refractive index 1.68), polycarbonate beads, polyethylene beads and the like. The plastic beads preferably have a hydrophobic group on the surface, and examples thereof include styrene beads.
Examples of other anti-glare fine particles made of an inorganic material include amorphous silica.

As the amorphous silica, it is preferable to use silica beads having an average particle diameter of 0.5 to 5 μm having good dispersibility.
The content of the amorphous silica is preferably 1 to 30 parts by mass with respect to the matrix resin. In order to improve the dispersibility of the amorphous silica without causing an increase in the viscosity of the composition for forming the internal scattering layer, the average particle size and the addition amount are changed, and the presence or absence of organic matter treatment on the particle surface Can also be used with modification. When the organic substance treatment is performed on the particle surface, a hydrophobic treatment is preferable. The average particle diameter of the amorphous silica can be measured by the method described above.

The organic matter treatment includes a method of chemically bonding a compound to the bead surface and a physical method of penetrating into a void in a composition forming the bead without chemically bonding to the bead surface. Yes, you can use either one. In general, a chemical treatment method using an active group on the silica surface such as a hydroxyl group or a silanol group is preferably used from the viewpoint of treatment efficiency. As the compound used for the treatment, a silane-based, siloxane-based, silazane-based material or the like having high reactivity with the active group is used. For example, linear alkyl single group substituted silicone materials such as methyltrichlorosilane, branched alkyl monosubstituted silicone materials, or polysubstituted linear alkyl silicone compounds such as di-n-butyldichlorosilane and ethyldimethylchlorosilane, and polysubstituted branched A chain alkyl silicone compound. Similarly, mono-substituted, poly-substituted siloxane materials and silazane materials having a linear alkyl group or a branched alkyl group can also be used effectively.

Depending on the required function, those having a hetero atom, an unsaturated bond group, a cyclic bond group, an aromatic functional group or the like may be used at the terminal or intermediate part of the alkyl chain. In these compounds, the alkyl group contained is hydrophobic, so that the surface of the material to be treated can be easily converted from hydrophilic to hydrophobic, and both the high-molecular material with poor affinity when untreated is high. Affinity can be obtained.

Examples of a method for applying the internal scattering layer forming composition to the light-transmitting substrate include application methods such as a roll coating method, a Miya bar coating method, and a gravure coating method.
After application of the internal scattering layer-forming composition, the resin having the curing reactivity in the internal scattering layer-forming composition is cured by drying, ultraviolet curing, electron beam curing, or the like as necessary. Thus, the internal scattering layer is formed.

Examples of the ultraviolet light source used for the ultraviolet curing include light sources of ultra-high pressure mercury lamp, high pressure mercury lamp, low pressure mercury lamp, carbon arc lamp, black light fluorescent lamp, and metal halide lamp lamp. As the wavelength of the ultraviolet light, a wavelength range of 190 to 380 nm can be used. Various electron beam accelerators such as cockcroft-wald type, bande graft type, resonant transformer type, insulated core transformer type, linear type, dynamitron type, high frequency type, etc. are mentioned as the electron beam source when performing the electron beam curing. It is done.

The internal scattering layer forming composition is preferably cured at a gel fraction of 80 to 100% to form the internal scattering layer. When the gel fraction is within the above range, the material is sufficiently cured and crosslinked, which is preferable in terms of surface hardness, scratch resistance, and durability.

In general, the dry thickness (at the time of curing) of the internal scattering layer is preferably set such that the lower limit is 0.1 μm and the upper limit is about 100 μm, particularly the lower limit is 0.8 μm and the upper limit is 10 μm. When the film thickness is within this range, the function as an internal scattering layer can be sufficiently exhibited. However, the dry thickness of the internal scattering layer is preferably larger than the average particle diameter of the internal scattering particles. If the dry thickness of the internal scattering layer is less than or equal to the average particle size of the internal scattering particles, the function as the internal scattering layer may not be exhibited sufficiently. Specifically, it is preferably about 1.05 to 3.50 times the average particle diameter of the internal scattering particles.
The thickness of the internal scattering layer can be measured by observing the cross section with an electron microscope (SEM, TEM, STEM).

The internal scattering layer may be further subjected to a shaping process that imparts an uneven shape. Such a shaping process can be suitably performed by a shaping process using a mold having an uneven shape opposite to the uneven shape of the internal scattering layer. Examples of the mold having the reverse uneven shape include an emboss plate and an emboss roll.

As the above-mentioned shaping treatment, the composition for forming the internal scattering layer may be applied and then shaped with the uneven shape, or the composition for forming the internal scattering layer may be supplied to the interface between the light-transmitting substrate and the uneven shape. Then, the composition for forming the internal scattering layer may be interposed between the concave-convex mold and the light-transmitting substrate, and the formation of the concave-convex shape and the formation of the internal scattering layer may be performed simultaneously. In the present invention, a flat embossed plate can be used instead of the embossed roller.

The concavo-convex surface formed on the embossing roller or the flat embossing plate can be formed by various known methods such as a sandblasting method or a bead shot method. The internal scattering layer formed using an embossing plate (embossing roller) by the sandblasting method has a shape in which a large number of concave shapes are distributed when the uneven shape is viewed in cross section. The internal scattering layer formed by using an embossed plate (embossing roller) by the bead shot method has a shape in which a number of convex shapes are distributed on the upper side when the concave and convex shapes are viewed in cross section.

When the average roughness of the concavo-convex shape formed on the surface of the internal scattering layer is the same, the internal scattering layer having a shape in which many convex portions are distributed on the upper side has a shape in which many concave portions are distributed on the upper side. It is said that there are few reflections, such as an indoor illuminating device, compared with what is doing. Therefore, according to a preferred aspect of the present invention, it is preferable to form the concavo-convex shape of the internal scattering layer using a concavo-convex mold formed in the same shape as the concavo-convex shape of the internal scattering layer by the bead shot method.

As a mold material for forming the concavo-convex mold surface, plastic, metal, wood or the like can be used, and a composite of these may be used. As the mold material for forming the concavo-convex mold surface, metal chromium is preferable from the viewpoint of strength and wear resistance due to repeated use. From the viewpoint of economy and the like, chromium is applied to the surface of the iron embossing plate (embossing roller). Plating is preferred.

Specific examples of the particles (beads) to be sprayed when forming the concavo-convex mold by the sandblasting method or the bead shot method include inorganic particles such as metal particles, silica, alumina, or glass. The particle diameter (diameter) of these particles is preferably about 30 to 200 μm. When spraying these particles onto the mold material, a method of spraying these particles together with a high-speed gas can be used. At this time, an appropriate liquid such as water may be used in combination. Further, in the present invention, it is preferable to use a concavo-convex mold formed with a concavo-convex shape after chromium plating or the like for the purpose of improving durability during use. Is preferable.

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

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

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

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

The thickness of the light transmissive substrate is preferably a lower limit of 20 μm and an upper limit of 300 μm, more preferably a lower limit of 30 μm and an upper limit of 200 μm. However, when the light-transmitting substrate is a plate-like body, the thickness may exceed these thicknesses. The light-transmitting substrate has a physical treatment such as a corona discharge treatment and an oxidation treatment in order to improve adhesion when forming the internal scattering layer and the antistatic layer described later on the light-transmitting substrate. Application of a coating material called an anchor agent or primer may be performed in advance.

The optical layered body of the present invention may be provided with other layers as necessary. Other layers are not limited as long as they are used for ordinary optical laminates such as a low refractive index layer, an antifouling layer, an antistatic layer, a hard coat layer, and an antireflection layer.

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

The low refractive index layer is preferably 1) a resin containing silica or magnesium fluoride, 2) a fluorine resin which is a low refractive index resin, 3) a fluorine resin containing silica or magnesium fluoride, 4) It is composed of either silica or magnesium fluoride thin film. About resin other than the said fluorine-type resin, resin similar to resin which comprises the said composition for internal scattering layer formation can be used.

As the fluororesin, a polymerizable compound containing a fluorine atom in at least a molecule or a polymer thereof can be used. Although it does not specifically limit as said polymeric compound, For example, what has hardening reactive groups, such as an ionizing radiation curable group and a thermosetting polar group, is preferable. Moreover, the compound which has these reactive groups simultaneously may be sufficient. In contrast to this polymerizable compound, the polymer has no reactive group as described above.

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

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

The polymerizable compound having both the ionizing radiation curable group and the thermosetting polar group includes acrylic or methacrylic acid moieties and fully fluorinated alkyl, alkenyl, aryl esters, fully or partially fluorinated vinyl ethers, completely or partially. Examples thereof include fluorinated vinyl esters, fully or partially fluorinated vinyl ketones and the like.

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

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

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

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

Further, together with the above-described polymerizable compound or polymer having a fluorine atom, each resin component as described in the composition for forming an internal scattering layer can be mixed and used. Furthermore, various additives and solvents can be used as appropriate in order to improve the curing agent for curing reactive groups and the like, to improve the coating property, and to impart antifouling properties.

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

In the low refractive index layer, it is preferable to use “fine particles having voids” as the low refractive index agent. The “fine particles having voids” can lower the refractive index while maintaining the layer strength of the low refractive index layer. In the present invention, the term “fine particles having voids” refers to a structure in which a gas is filled with gas and / or a porous structure containing gas, and the gas in the fine particle is compared with the original refractive index of the fine particle. It means fine particles whose refractive index decreases in inverse proportion to the occupation ratio. The present invention also includes fine particles capable of forming a nanoporous structure at least inside and / or on the surface depending on the form, structure, aggregated state, and dispersed state of the fine particles inside the coating. The low refractive index layer using these fine particles can adjust the refractive index to 1.30 to 1.45.

Examples of the inorganic fine particles having voids include silica fine particles prepared by the method described in JP-A-2001-233611. Further, it may be silica fine particles obtained by the production methods described in JP-A-7-133105, JP-A-2002-79616, JP-A-2006-106714, and the like. Since silica fine particles having voids are easy to manufacture and have high hardness, when a low refractive index layer is formed by mixing with a binder, the layer strength is improved and the refractive index is 1.20-1. It is possible to prepare within the range of about 45. In particular, as specific examples of the organic fine particles having voids, hollow polymer fine particles prepared by using the technique disclosed in JP-A-2002-80503 are preferably exemplified.

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

The average particle size of the “fine particles having voids” is 5 nm or more and 300 nm or less, preferably the lower limit is 8 nm or more and the upper limit is 100 nm or less, more preferably the lower limit is 10 nm or more and the upper limit is 80 nm or less. When the average particle diameter of the fine particles is within this range, excellent transparency can be imparted to the low refractive index layer. The average particle diameter is a value measured by a dynamic light scattering method or the like. The “fine particles having voids” are usually about 0.1 to 500 parts by mass, preferably about 10 to 200 parts by mass with respect to 100 parts by mass of the resin in the low refractive index layer.

The solvent is not particularly limited, and examples thereof include those exemplified in the composition for forming an internal scattering layer. Preferably, methyl isobutyl ketone, cyclohexanone, isopropyl alcohol (IPA), n-butanol, t-butanol, diethyl Ketone, PGME and the like.

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

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

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

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

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

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

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

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

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

Antistatic layer The optical layered body of the present invention may further have an antistatic layer. The antistatic layer can be formed of a composition containing an antifouling agent and a resin. It does not specifically limit as said resin, Resin illustrated by the above-mentioned composition for internal scattering layer formation can be mentioned.

The antistatic agent is not particularly limited, and examples thereof include cationic compounds such as quaternary ammonium salts, pyridinium salts, and primary to tertiary amino groups; sulfonate groups, sulfate ester bases, phosphate ester bases, and phosphonic acids. Anionic compounds such as bases; amphoteric compounds such as amino acids and aminosulfate esters; nonionic compounds such as amino alcohols, glycerin and polyethylene glycol; organometallic compounds such as tin and titanium alkoxides; Examples thereof include metal chelate compounds such as acetylacetonate salts of compounds. Compounds obtained by increasing the molecular weight of the compounds listed above can also be used. Also, polymerizability of organometallic compounds such as coupling agents having a tertiary amino group, a quaternary ammonium group or a metal chelate moiety and having a monomer, oligomer or functional group that can be polymerized by ionizing radiation. Compounds can also be used as antistatic agents.

Examples of the antistatic agent include conductive polymers. The conductive polymer is not particularly limited. For example, aromatic conjugated poly (paraphenylene), heterocyclic conjugated polypyrrole, polythiophene, aliphatic conjugated polyacetylene, heteroatom-containing polyaniline, mixed type Conjugated poly (phenylene vinylene), a double chain conjugated system that has a plurality of conjugated chains in the molecule, and a conductive polymer that is a polymer obtained by grafting or block-copolymerizing the conjugated polymer chain to a saturated polymer. And the like.

The antistatic agent may be conductive metal oxide fine particles. The conductive metal oxide fine particles are not particularly limited. For example, ZnO (refractive index 1.90, hereinafter, all values in parentheses indicate refractive index), Sb ₂ O ₂ (1.71). ), SnO ₂ (1.997), CeO ₂ (1.95), indium tin oxide (abbreviated as ITO; 1.95), In ₂ O ₃ (2.00), Al ₂ O ₃ (1.63), Antimony-doped tin oxide (abbreviation ATO; 2.0), aluminum-doped zinc oxide (abbreviation AZO; 2.0), and the like can be given.

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

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

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

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

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

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

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

ADVANTAGE OF THE INVENTION According to this invention, the optical laminated body which showed favorable contrast and prevented glare can be obtained, maintaining anti-glare property.

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

According to the following manufacture example, the composition for internal scattering particle | grains and internal scattering layer formation was prepared.

Production Example 1 (Preparation of Encapsulated Fine Particle Dispersion (1))
Fine particle titanium oxide (manufactured by Teika Co., Ltd., MT-600B, average particle size 50 nm) 18.67 parts, dispersant (Bic Chemie Japan Co., Ltd., DISPER BYK-163) 3.73 parts, KAYARAD PET- 30 (Nippon Kayaku Co., Ltd.) 7.47 parts, polymerization initiator Irgacure 184 (Ciba Specialty Chemicals Co., Ltd.) 0.41 parts was added to 69.7 parts of methyl isobutyl ketone, and this solution was dispersed in a bead mill. Dispersion was carried out using a machine ZRS (manufactured by Ashizawa Finetech Co., Ltd.) to prepare an encapsulated fine particle dispersion (1).

Production Example 2 (Preparation of encapsulated fine particle dispersion (2))
Fine particle zirconia (manufactured by Tosoh Corporation, TZ-3Y-E, average particle size 50 nm) 18.67 parts, dispersant (Big Chemy Japan, Ltd., DISPER BYK-163) 3.73 parts, KAYARAD PET -30 (Nippon Kayaku Co., Ltd.) 7.47 parts, polymerization initiator Irgacure 184 (Ciba Specialty Chemicals) 0.41 part was added to 69.7 parts of methyl isobutyl ketone, and this solution was added to a bead mill. Dispersion was performed using a disperser ZRS (manufactured by Ashizawa Finetech Co., Ltd.) to prepare an encapsulated fine particle dispersion (2).

Production Example 3 (Preparation of Encapsulated Fine Particle Dispersion (3))
Ultrafine zinc oxide (Sumitomo Osaka Cement Co., Ltd., average particle size 50 nm) 18.67 parts, Dispersant (Big Chemy Japan Co., Ltd., DISPER BYK-163) 3.73 parts, KAYARAD PET-30 7.47 parts (manufactured by Nippon Kayaku Co., Ltd.) and 0.41 part of polymerization initiator Irgacure 184 (manufactured by Ciba Specialty Chemicals) were added to 69.7 parts of methyl isobutyl ketone, and this solution was added to a bead mill disperser. Dispersion was carried out with ZRS (manufactured by Ashizawa Finetech Co., Ltd.) to prepare an encapsulated fine particle dispersion (3).

Production Example 4 (Preparation of encapsulated fine particle dispersion (4))
Ultrafine particle alumina (manufactured by Nippon Light Metal Co., Ltd., average particle size 50 nm) 18.67 parts, dispersant (manufactured by Big Chemie Japan Co., Ltd., DISPER BYK-163) 3.73 parts, KAYARAD PET-30 (Japan) 7.47 parts of Kayaku Co., Ltd.) and 0.41 part of polymerization initiator Irgacure 184 (manufactured by Ciba Specialty Chemicals) are added to 69.7 parts of methyl isobutyl ketone, and this solution is added to a bead mill disperser ZRS ( Ashizawa Finetech Co., Ltd.) to prepare an encapsulated fine particle dispersion (4).

Production Example 5 (Preparation of internal scattering particles (1))
695 parts of ion exchange water, 100 parts of the encapsulated fine particle dispersion (1) prepared in Production Example 1, 5 parts of sodium dodecyl sulfate, and 80 parts of ethyl acetate were added and stirred well. 286 parts of a mixed solution of styrene / methyl methacrylate (MMA) (weight ratio 50/50) was added thereto, and the obtained mixed solution was then added using a TK homomixer [manufactured by Special Machine Industries Co., Ltd.]. The mixture was stirred at 12000 rpm for 2 minutes. Then, it moved to the pressure | voltage resistant reaction container, the internal scattering particle | grains (1) which concern on Example 1 were obtained by desolvating at normal pressure, heating up to 40 degreeC. Table 1 shows the refractive index and particle size of the particle matrix component of the obtained internal scattering particles (1), and the particle size and refractive index of the encapsulated fine particles.

Furthermore, the volume of the obtained internal scattering particles (1) and the total volume of these inclusion fine particles are calculated from the average radius of the internal scattering particles and the inclusion fine particles by TEM observation, and further from the TEM observation, the volume of the inclusion fine particles is calculated. The average number of particles was calculated, and the volume fraction of encapsulated fine particles {= (total volume of encapsulated particles / volume of internally scattered particles) × 100} was calculated. The results are shown in Table 1.

Production Example 6 (Preparation of internal scattering particles (2))
Internal scattering particles (2) according to Example 2 were prepared in the same manner as in Production Example 5 except that the weight ratio of styrene / methyl methacrylate (MMA) was 100/0. The refractive index and particle size of the particle matrix component of the obtained internal scattering particles (2), the particle size and refractive index of the encapsulated fine particles, and the volume fraction of the encapsulated fine particles measured in the same manner as in Production Example 5 are shown. It is shown in 1.

Production Example 7 (Preparation of internal scattering particles (3))
200 parts of neopentyl glycol, 93 parts of ethylene glycol and 355 parts of terephthalic acid were added to the reactor, and the reaction was allowed to proceed for 2 hours while heating to 230 ° C. and distilling off the generated water. Thereafter, 0.2 part of dibutyltin oxide is added, and the reaction is continued until the acid value becomes 0.5 or less, whereby a polyester resin having a hydroxyl group at both ends, a number average molecular weight of 7000, and a hydroxyl value of 17 (polyester) Resin).
In a beaker, 93 parts of the obtained polyester resin, 7 parts of MEK oxime-blocked HDI trimer (manufactured by Asahi Kasei, Sumijoule) and 100 parts of tetrahydrofuran were mixed, and this was added to the encapsulated fine particle dispersion (1). After adding to 100 parts, an ultradisperser (manufactured by Yamato Kagaku) was used and mixed for 1 minute at a rotation speed of 9000 rpm to obtain an average particle size of 4 μm. After mixing, this mixed solution was put into a four-necked flask equipped with a stirring bar and a thermometer, and the solvent was removed at room temperature and reduced pressure for 10 hours. Next, 0.1 part of urethanization catalyst [TEDA, manufactured by Tosoh Corporation], 0.1 part of light-resistant stabilizer [DIC-TBS, manufactured by Dainippon Ink & Chemicals, Inc.], rheology modifier [SN thickener-651, manufactured by San Nopco] 3.0 parts were added, and the internal scattering particles (3) according to Example 3 were obtained. The refractive index and particle size of the particle matrix component of the internally scattered particles (3) obtained, the particle size and refractive index of the encapsulated fine particles, and the volume fraction of the encapsulated fine particles measured in the same manner as in Production Example 5 are shown. It is shown in 1.

Production Example 8 (Preparation of internal scattering particles (4) to (11))
Internal scattering particles according to Examples 4 to 11 in the same manner as in Production Examples 5 to 7 except that the particle matrix component, which is the main raw material of the encapsulated fine particles and the internal scattering particles, was appropriately changed so as to become the material shown in Table 1 below. (4) to (11) were prepared. The refractive index and particle size of the particle matrix component of the obtained internal scattering particles (4) to (11), the particle size and refractive index of the encapsulated fine particles, and the volume of the encapsulated fine particles measured in the same manner as in Production Example 5. The fractions are shown in Table 1.

Production Example 9 (Preparation of outer attached particles (1))
A pressure-resistant reaction vessel was charged with 735 parts of ion-exchanged water, 50 parts of sodium dodecyl sulfate, 5 parts of ammonium persulfate, and 10 parts of sodium hydrogen carbonate. After the air in the reaction vessel was replaced with nitrogen, the reaction vessel was sealed up to 80 ° C. The temperature rose. Then, 200 parts of a mixed monomer of styrene / methacrylic acid / butyl acrylate (weight ratio 30/30/40) was added dropwise over 2 hours. Further, aging was carried out at the same temperature for 2 hours to obtain outer attached particles (1). The average particle diameter of the obtained outer adhered particles (1) was 50 nm.

Production Example 10 (Preparation of shell-attached particles (2))
The outer adhered particles (2) were prepared in the same manner as in Production Example 9 except that the dropping time of the mixed monomer was 1 hour. The outer particle (2) obtained had an average particle size of 100 nm.

Production Example 11 (Preparation of internal scattering particles (12))
Filling 900 parts of the inner scattering particles (1) obtained in Production Example 5 with 100 parts of the outer shell adhering particles (1) in a hybridization system [manufactured by Nara Machinery Co., Ltd.] and treating them at 12000 rpm for 50 seconds. Thus, the internal scattering particles (12) according to Example 12 to which the outer particles (1) were adhered were obtained. The refractive index and particle size of the particle matrix component of the obtained internal scattering particles (12), the particle size and refractive index of the encapsulated fine particles, and the volume fraction of the encapsulated fine particles measured in the same manner as in Production Example 5 are shown. It is shown in 1. The volume fraction of the outer adhered particles (1) was 18% of the inner scattering particles (1).

Production Example 12 (Preparation of internal scattering particles (13))
The internal scattering particles (13) according to Example 13 to which the outer particles (2) were adhered were prepared in the same manner as in Production Example 11, except that the outer particles (1) were changed to outer particles (2). Obtained. The refractive index and particle size of the particle matrix component of the obtained internal scattering particles (13), the particle size and refractive index of the encapsulated fine particles, and the volume fraction of the encapsulated fine particles measured in the same manner as in Production Example 5 are shown. It is shown in 1. The volume fraction of the outer-attached particles (2) was 13% of the inner scattering particles (13).

Production Example 13 (Preparation of internal scattering particles (14))
Internal scattering particles (14) according to Comparative Example 1 were prepared in the same manner as in Production Example 6, except that the encapsulated fine particle dispersion (1) was not added in Production Example 6. Table 1 shows the refractive index and particle size of the particle matrix component of the internally scattered particles (14) obtained.

Production Example 14 (Preparation of internal scattering particles (15) to (17))
Internal scattering particles (15) to (17) according to Comparative Examples 2 to 4 were prepared in the same manner as in Production Example 6 except that the stirring conditions of the TK homomixer were changed. The refractive index and particle size of the particle matrix component of the internal scattering particles (15) to (17) obtained, the particle size and refractive index of the encapsulated fine particles, and the volume of the encapsulated fine particles measured in the same manner as in Production Example 5. The fractions are shown in Table 1.

Production Example 15 (Preparation of composition for forming internal scattering layer (1))
Pentaerythritol triacrylate (PETA) (Nippon Kayaku, refractive index 1.51)
65 parts by mass isocyanuric acid-modified diacrylate M215 (manufactured by Toagosei Co., Ltd.) 35 parts by mass polymethyl methacrylate (molecular weight 75,000) 10 parts by mass (photocuring initiator)
Irgacure 184 (Ciba Specialty Chemicals Co., Ltd.) 6 parts by mass Irgacure 907 (Ciba Specialty Chemicals Co., Ltd.) 1 part by mass (internal scattering particles)
Internal scattering particles (1) (The blending amount was adjusted so that the particle / binder resin ratio shown in Table 1 was obtained.)
(Leveling agent)
Silicone leveling agent, manufactured by Dainichi Seika Co., Ltd. 0.045 parts by mass (solvent)
Toluene 64 parts by mass Cyclohexanone 16 parts by mass The above materials were sufficiently mixed to prepare a composition. This composition was filtered through a polypropylene filter having a pore size of 30 μm to prepare an internal scattering layer forming composition (1) according to Example 1 having a solid content of 30% by mass.

Production Example 16 (Preparation of compositions for forming internal scattering layer (2) to (17))
Instead of the internal scattering particles (1), the internal scattering particles (2) to (17) were the same as in Production Example 15 except that the blending amount was adjusted to the particle / binder resin ratio shown in Table 1. Thus, compositions (2) to (17) for forming an internal scattering layer according to Examples 2 to 13 and Comparative Examples 1 to 4 were prepared.

Example 1
Using a triacetyl cellulose (TAC) film (Fuji Photo Film, TF80UL, thickness 80 μm) as a transparent substrate, the composition for forming an internal scattering layer (1) is coated on the film with a winding rod (Meyer's bar) Using # 8, apply to a dry film thickness of 4 μm, heat dry in an oven at 70 ° C. for 2 minutes, evaporate the solvent, and then irradiate with ultraviolet rays to a dose of 130 mJ. Was cured to form an internal scattering layer, and an optical laminate having a thickness of 4.2 μm was obtained.

Examples 2-13, Comparative Examples 1-4
An optical laminate having the thickness shown in Table 1 in the same manner as in Example 1 except that the compositions (2) to (17) for forming the internal scattering layer were used instead of the composition (1) for forming the internal scattering layer. Manufactured.

The following evaluation was performed about the obtained optical laminated body. The results are shown in Table 1.

Evaluation 1 Internal haze The internal haze value was measured according to JIS K-7136. As a measuring instrument, a reflection / transmittance meter HM-150 (Murakami Color Research Laboratory) was used.

Evaluation 2 Front C / R reduction rate measurement (preparation of polarizing plate)
The optical layered body was saponified into two parts with 55 ° C. and 2N NaOH aqueous solution, and then the polarizing plate with TF80UL bonded on one side was bonded to the polarizer surface on the side of the optical layered body that was not the coating surface. A) was prepared.
(Front C / R reduction rate measurement)
A polarizing plate (A) is attached to the front side of the liquid crystal cell of a BRAVIA 27-inch panel made by Sony, and a polarizing plate with triacetyl cellulose attached to both sides of the polarizer is attached to the back side of the liquid crystal cell in a crossed Nicol arrangement. C / R was measured using a BM-5 luminance meter manufactured by Topcon Techno House. As the polarizing plate (A), the C / R of the optical laminate not including the internal scattering layer was 890. In Example 1, which is an optical laminate including an internal scattering layer, C / R was 863, and the C / R reduction rate was 3%.

Evaluation 3 A black matrix pattern plate (105 ppi, 140 ppi) formed on a 0.7 mm-thick glass is placed on a viewer made of Glitter HAKUBA (Light Viewer 7000PRO) with the pattern surface facing down, and the optical obtained thereon The laminated film was placed with the concavo-convex surface on the air side, and glare was visually observed in a dark room while lightly pressing the edge of the film with a finger so that the film did not float, and evaluated according to the following criteria.
Evaluation standard evaluation ◎: Good evaluation with no glare at 140 ppi ○: Good evaluation without glare at 105 ppi Δ: No glare at 105 ppi

Evaluation 4 Cracking property When the manufactured optical laminate was wound around a metal roll having a diameter of 0.5 cm, the presence or absence of cracks was visually confirmed, and evaluated according to the following criteria.
Evaluation criteria Evaluation ○: No crack evaluation ×: Crack present

Evaluation 5 The sedimentation state of the internal scattering particles in the composition for forming an internal scattering layer prepared for ink dispersibility after one day was visually confirmed and evaluated according to the following criteria.
Evaluation criteria Evaluation ○: No particle sedimentation evaluation Δ: Particle sedimentation, but uniformly dispersed after stirring Evaluation ×: Particle sedimentation, no dispersion after stirring

Table 1 shows that the optical layered body of the present invention is an optical layered body having a low C / R reduction rate, excellent antiglare effect, and excellent crackability and ink dispersibility.

According to the present invention, an optical layered body excellent in antiglare property, contrast, and glare prevention effect can be formed. The obtained optical laminate can be suitably used as an antireflection laminate. Therefore, the optical laminate of the present invention can be suitably applied to a cathode ray tube display (CRT), a liquid crystal display (LCD), a plasma display (PDP), an electroluminescence display (ELD) and the like.

It is sectional drawing which shows an example of an internal scattering particle typically.

Explanation of symbols

10 Internal scattering particles 11 Encapsulated fine particles 12 Binder component

Claims (8)

An optical laminate having a light transmissive substrate and an internal scattering layer containing internal scattering particles provided on the light transmissive substrate,
The internal scattering particles have an average particle diameter of 1 to 10 μm , contain a particle matrix component made of an organic resin having a refractive index of 1.50 or more, and have an average particle diameter of 5 to 300 nm. Or enclose fine particles made of an inorganic material having a refractive index of 1.55 or more ,
In the internal scattering layer, the internal scattering particles are dispersed in a matrix resin,
Assuming that the refractive index of the fine particles encapsulated in the internal scattering particles is n _A , the refractive index of components other than the fine particles encapsulated in the internal scattering particles is n _B , and the refractive index of the matrix resin is n _C , n _A , n _B And n _C satisfy the following formula (1) .
n _C <n _B <n _A (1) 2. The optical laminate according to 1 , wherein the internal scattering particles have a volume fraction of encapsulated fine particles {= (total volume of encapsulated fine particles / volume of internal scattering particles) × 100} of 30% or less. Fine particles contained inside the scattering particles, a refractive index of 1.55 or more, and titanium oxide, zinc oxide, according to claim 1 or 2, wherein at least one selected from the group consisting of zirconia and alumina Optical laminate. The optical layered body according to claim 1, 2 or 3 , wherein the internal scattering particles further have outer adhering particles that are physically adsorbed with an average particle diameter of 1 µm or less in the outer portion. The optical laminated body according to claim 1, 2, 3, or 4, which is used as an antireflection laminated body. A self-luminous image display device comprising the optical laminate according to claim 1, 2, 3, 4, or 5 on an outermost surface. A polarizing plate comprising a polarizing element,
A polarizing plate, wherein the surface of the polarizing element comprises claims 1, 2, 3, 4 or 5 optical laminate according. A non-self-luminous image display device comprising the optical laminate according to claim 1, 2, 3, 4 or 5 or the polarizing plate according to claim 7 on an outermost surface.

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