JP4895160B2 - Optical laminate - Google Patents

Description

  The present invention relates to an optical laminate, and particularly to an antireflection laminate.

  An image display surface in an image display device such as a liquid crystal display (LCD) or a cathode ray tube display device (CRT) is required to reduce reflection by light emitted from an external light source such as a fluorescent lamp and to improve its visibility. The On the other hand, by providing an optical laminate (for example, an antireflection laminate) in which the reflectance is lowered by coating the surface of a transparent object with a transparent film having a low refractive index, The reflection on the display surface is reduced and the visibility is improved. As an example of the antireflection laminate, there may be mentioned one formed by laminating an antiglare layer and a refractive index layer on the surface of a light transmission type substrate.

  Conventionally, in an optical layered body, desired optical characteristics have been found by selecting suitable ones for the physical properties of the additives (conductive particles, anti-glare agent) of each layer, the addition amount thereof, and the like. For example, in Japanese Patent Application Laid-Open No. 2003-75605 (Patent Document 1), an appropriate value is selected for the refractive index, particle diameter, particle blending, etc. of the transparent resin used in the antiglare layer, and It has been proposed to improve the optical properties.

However, the present inventors have confirmed that, by focusing on the correlation between the layers of the optical laminate, and adjusting the respective layers, the optical properties of the optical laminate itself are improved, and an optical laminate with high definition specifications is obtained. No report has been made that it has been developed.
JP 2003-75605 A

  At the time of the present invention, the inventors focused on the interface between the light transmissive substrate and the antiglare layer, and the permeable solvent and the resin added to the composition for the antiglare layer serve as the light transmissive substrate. It was found that excellent optical properties can be imparted by permeation and forming a permeation layer. Therefore, the present invention has been made under such knowledge.

Therefore, the optical laminate according to the present invention is
A light-transmitting substrate and an antiglare layer on the light-transmitting substrate,
The antiglare layer is formed by applying the antiglare layer composition on the light transmissive substrate,
The permeable solvent and the resin contained in the antiglare layer composition penetrate into the light-transmitting substrate, and the resin and the light-transmitting substrate are integrally integrated to form an osmotic layer. It will be.

An optical laminate according to another preferred embodiment of the present invention comprises a light-transmitting substrate, and an antistatic layer and an antiglare layer on the light-transmitting substrate in this order. There,
The antiglare layer is formed by applying the antiglare layer composition on the antistatic layer, and the permeable solvent and the resin contained in the antiglare layer composition are It penetrates into the light transmissive base material, and the resin and the light transmissive base material are naturally integrated to form a permeation layer.

An optical laminate according to another preferred embodiment of the present invention is an optical laminate comprising a light transmissive substrate, a hard coat layer on the light transmissive substrate, and an antiglare layer in this order. There,
The antiglare layer is formed by applying the antiglare layer composition on the hard coat layer, and the permeable solvent and the resin contained in the antiglare layer composition are It penetrates into the light transmissive base material, and the resin and the light transmissive base material are naturally integrated to form a permeation layer.

  According to the optical layered body of the present invention, since the permeation layer is formed, it is possible to exhibit optical characteristics such as prevention of reflection of a fluorescent lamp or the like on the display display screen and surface glare. Moreover, in the uneven | corrugated shape formed in the outermost surface of an anti-glare layer, since a desired uneven | corrugated shape is formed, without a resin component adhering to a glare-proof agent in large quantities, it is preferable. In the present invention, the “surface glare” is a glare light that impairs the visibility that is caused by the uneven shape when transmitted light from the inside of the display reaches the viewer's eyes from the display surface. Say.

1. Optical Laminate The optical laminate according to the present invention will be described with reference to FIG. FIG. 1 is a schematic view of an optical laminate 1. The optical laminate 1 (antireflection laminate) is formed by forming an antiglare layer 7 and a low refractive index layer 9 on the upper surface of a light-transmitting substrate 2. When the antiglare layer composition is applied onto the light transmissive substrate 2, the permeable solvent and the resin contained in the antiglare layer composition penetrate from the outermost surface of the light transmissive substrate 2. And the penetration layer 3 in which resin contained in the composition for glare-proof layers and a light-transmitting base material were united naturally was formed. By forming the osmotic layer 3, the optical laminate according to the present invention can exhibit excellent optical characteristics. For the sake of clarity, the permeation layer 3 is depicted as being present between the antiglare layer 7 and the light transmissive substrate 2 in FIG. 1, but in the present invention, these three layers are substantially formed. In such a laminate, such a laminate is preferable.

  A preferred optical laminate according to the present invention will be described with reference to FIG. FIG. 2 shows a schematic view of the optical laminate 10 (antireflection laminate). This optical laminate 10 is obtained by laminating an antistatic layer 5 or a hard coat layer 5 between a light-transmitting substrate 2 and an antiglare layer 7 in the optical laminate 1 shown in FIG. When the antiglare layer composition is applied onto the antistatic layer 5 or the hard coat layer 5, the permeable solvent and the resin contained in the antiglare layer composition become the antistatic layer 5 or the hard coat layer. 5, penetrates from the outermost surface of the light-transmitting substrate 2, and the penetrating layer 3 is formed in which the resin contained in the antiglare layer composition and the light-transmitting substrate are naturally integrated. . For easy understanding, the permeation layer 3 is depicted as being present between the antistatic layer 5 or the hard coat layer 5 and the light-transmitting substrate 2 in FIG. 2. The three layers are formed so that there is substantially no interface, and such a laminate is preferable.

  Further, according to a more preferred embodiment of the present invention, in the optical laminate 10 shown in FIG. 2, the antistatic layer 5 or the hard coat layer 5 is an antistatic layer composition on the light transmissive substrate 2. Alternatively, the antiglare layer 7 is formed by applying the antiglare layer composition on the antistatic layer 5 or the hard coat layer 5. The permeable solvent and resin contained in the antistatic layer composition or the hard coat layer composition and the permeable solvent and resin contained in the antiglare layer composition are light. The resin penetrated into the transmissive substrate 2 and contained in the antistatic layer composition or the hard coat layer composition, the resin contained in the antiglare layer composition, and the light transmissive substrate were stunning. An optical layered body in which the penetrating layer 3 formed as a unit is formed is proposed.

  In the optical layered body in the present invention, it is preferable that the permeable solvent does not remain in the permeable layer 3 in the optical layered product that is the final product.

1) Penetration layer Presence of the penetration layer substantially eliminates the interface between each layer such as a light-transmitting base material and an antiglare layer (an antistatic layer, a hard coat layer), and prevents interference fringes. Optical properties can be imparted. In addition, the resin component of the antiglare layer can be adjusted, and as a result, the uneven shape on the outermost surface of the antiglare layer can be formed into a desired shape.

  In the present invention, the thickness of the permeation layer is 0.1 μm or more and 1.5 μm or less, preferably the lower limit is 0.3 μm or less, the lower limit is 0.9 μm or more, more preferably the lower limit is It is 0.5 μm or less, and the lower limit is 0.7 μm or more. The thickness of the osmotic layer may be appropriately adjusted depending on the amount of the permeable solvent to be described later.

2) Antiglare layer The antiglare layer may be formed of a permeable solvent, a resin, and an antiglare agent. The film thickness of the antiglare layer is in the range of 0.1 to 100 μm, preferably 0.8 to 20 μm. When the film thickness is within this range, the function as an antiglare layer can be sufficiently exhibited.

1) Osmotic solvent In the present invention, the osmotic solvent means a solvent having any action such as permeability, swellability, and osmotic solubility.
Specific examples of the osmotic solvent include acetone, ketone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, nitromethane, 1,4-dioxane, dioxolane, N-methylpyrrolidone, ethyl acetate, methyl acetate, butyl acetate, dichloromethane, trichloromethane, trichloroethylene, Examples thereof include ethylene chloride, trichloroethane, tetrachloroethane, N, N-dimethylformamide, and chloroform, and preferably one or more selected from the group consisting of methyl ethyl ketone, cyclohexanone, tetrahydrofuran, ethyl acetate, methyl acetate, dichloromethane, and chloroform Of the mixture.

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

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

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

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

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

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

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

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

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

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

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

Anti- glare agent The anti-glare agent may be either inorganic or organic, and may have any shape, for example, fine particles. Among the fine particles, resin beads are preferable. The fine particles preferably have a refractive index of 1.40 to 1.60. Since the refractive index of an ionizing radiation curable resin, particularly an acrylate or methacrylate resin, usually shows a value of 1.45 to 1.55, the refractive index of fine particles approximates the refractive index of an ionizing radiation curable resin. This is because it is possible to impart antiglare properties while maintaining the transparency of the optical layered body.

  Specific examples of resin beads having a refractive index close to the refractive index of the ionizing radiation curable resin (the parentheses indicate the refractive index) include polymethyl methacrylate beads (1.49), polycarbonate beads (1.58), polystyrene. Examples thereof include beads (1.60), polyacryl styrene peas (1.57), and polyvinyl chloride beads (1.54). The particle diameter of these resin beads is preferably 1-8 μm. The addition amount of the resin beads is 2 to 20 parts by weight, preferably about 16 parts by weight with respect to 100 parts by weight of the ionizing radiation curable resin.

  It is preferable to add an antisettling agent when adjusting the composition for the antiglare layer. This is because by adding an anti-settling agent, precipitation of the resin beads can be suppressed and the resin beads can be uniformly dispersed in the solvent. Specific examples of the anti-settling agent include silica beads having a particle size of 0.5 μm or less, preferably about 0.1 to 0.25 μm. The amount of silica beads added as an anti-settling agent is preferably less than about 0.1 parts by weight with respect to 100 parts by weight of ionizing radiation curable resin. This is because the amount of addition can effectively prevent sedimentation of the resin beads and sufficiently maintain the transparency of the coating film.

3) Light transmissive base material The light transmissive base material preferably has smoothness and heat resistance and is excellent in mechanical strength. Specific examples of materials forming the light-transmitting substrate include cellulose triacetate, polyester, cellulose diacetate, cellulose acetate butyrate, polyester, polyamide, polyimide, polyethersulfone, polysulfone, polypropylene, polymethylpentene, polychlorinated Examples thereof include thermoplastic resins such as vinyl, polyvinyl acetal, polyether ketone, polymethyl methacrylate, polycarbonate, and polyurethane, and preferably cellulose triacetate.
In the present invention, it is preferable to use these thermoplastic resins as a film body rich in thin film flexibility. Can also be used.
The thickness of the light transmissive substrate is 20 μm or more and 300 μm or less, preferably the upper limit is 200 μm or less, and the lower limit is 30 μm or more.

4) Other layers The optical layered body according to the present invention is basically composed of a light-transmitting substrate and an antiglare layer, but the following layers are preferably laminated for the purpose of improving optical properties. .

Antistatic Layer The antistatic layer is preferably laminated between the light transmissive substrate and the antiglare layer. The antistatic layer composition comprises an antistatic agent (conductive agent) and a resin.

Penetration Solvent According to a preferred embodiment of the present invention, those comprising a composition penetration solvent for an antistatic layer are preferred. The penetrating solvent may be the same as that described in the section of the antiglare layer composition. Addition of penetrating solvent contained in antistatic layer composition and penetrating solvent contained in antiglare layer composition when forming penetrating layer with antistatic layer composition and antiglare layer composition It is preferable to adjust the amount appropriately.

Antistatic agent (conductive agent)
Specific examples of the antistatic agent include quaternary ammonium salts, pyridinium salts, various cationic compounds having cationic groups such as primary to tertiary amino groups, sulfonate groups, sulfate ester bases, and phosphate ester bases. , Anionic compounds having an anionic group such as phosphonate group, amphoteric compounds such as amino acid series and amino sulfate ester series, nonionic compounds such as amino alcohol series, glycerin series and polyethylene glycol series, and alkoxides of tin and titanium And metal chelate compounds such as acetylacetonate salts thereof, and compounds obtained by increasing the molecular weight of the compounds listed above. Further, like a coupling agent having a tertiary amino group, a quaternary ammonium group, or a metal chelate portion and having a monomer or oligomer polymerizable by ionizing radiation or a functional group polymerizable by ionizing radiation. Polymerizable compounds such as organometallic compounds can also be used as antistatic agents.

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

3) The resin resin may be the same as described in the section of the antiglare layer composition.

Hard coat layer The hard coat layer is preferably laminated between the light-transmitting substrate and the antiglare layer. The composition for hard coat layers comprises a resin. In the present invention, the hard coat layer composition preferably further comprises a conductive agent. In the present invention, the “hard coat layer” refers to a layer having a hardness of “H” or higher in a pencil hardness test specified in JIS 5600-5-4: 1999. The thickness of the hard coat layer (during curing) is in the range of 0.1 to 100 μm, preferably 0.8 to 20 μm.

Penetration Solvent According to a preferred embodiment of the present invention, the hard coat layer composition may comprise a penetration solvent. The penetrating solvent may be the same as that described in the section of the antiglare layer composition. Addition of penetrating solvent contained in hard coat layer composition and penetrating solvent contained in antiglare layer composition when forming penetrating layer with hard coat layer composition and antiglare layer composition It is preferable to adjust the amount appropriately.

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

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

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

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

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

Optional ingredients
When forming a polymerization initiator hard coat layer, a photopolymerization initiator can be used, and specific examples thereof include 1-hydroxy-cyclohexyl-phenyl-ketone. This compound is commercially available, for example, trade name Irgacure 184 (manufactured by Ciba Specialty Chemicals).

The antistatic agent and / or antiglare agent hard coat layer preferably contains an antistatic agent and / or antiglare agent. The antistatic agent may be the same as described in the section of the antistatic layer composition, and the antiglare agent may be the same as described in the section of the antiglare layer composition.

Low Refractive Index Layer In the present invention, a layer formed by laminating a low refractive index layer is preferable, and specifically, it is preferably formed on an antiglare layer. The low refractive index layer is composed of a resin containing silica or magnesium fluoride, a fluorine resin as a low refractive index resin, silica or a fluorine resin containing magnesium fluoride, and a refractive index of 1.46 or less. The film can also be composed of a thin film of about 30 nm to 1 μm, or a thin film of silica or magnesium fluoride by chemical vapor deposition or physical vapor deposition. The resin other than the fluororesin is the same as the resin used for constituting the antistatic layer.

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

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

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

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

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

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

High Refractive Index Layer / Medium Refractive Index Layer According to a preferred embodiment of the present invention, other refractive index layers (high refractive index layer and medium refractive index layer) may be provided to further improve the antireflection property, preferably Is preferably provided between the antiglare layer and the low refractive index layer. The refractive index of these refractive index layers may be set within the range of 1.46 to 2.00. In the present invention, the middle refractive index layer means a layer having a refractive index in the range of 1.46 to 1.80, and the high refractive index layer has a refractive index of 1.65 to 2. Means within the range of .00.

  These refractive index layers may be formed of an ionizing radiation curable resin and ultrafine particles having a particle diameter of 100 nm or less and having a predetermined refractive index. Specific examples of such fine particles (in parentheses indicate refractive index) include zinc oxide (1.90), titania (2.3 to 2.7), ceria (1.95), tin-doped indium oxide (1 .95), antimony-doped tin oxide (1.80), yttria (1.87), and zirconia (2.0).

  The refractive index of the ultrafine particles is preferably higher than that of the ionizing radiation curable resin. Since the refractive index of the refractive index layer is generally determined by the content of ultrafine particles, the refractive index of the refractive index layer increases as the amount of ultrafine particles added increases. Therefore, by adjusting the addition ratio of the ionizing radiation curable resin and the ultrafine particles, a high refractive index layer or medium refractive index layer having a refractive index in the range of 1.46 to 1.80 is formed. Is possible.

  If the ultrafine particles have conductivity, the other refractive index layer (high refractive index layer or medium refractive index layer) formed using such ultrafine particles also has antistatic properties.

  The high refractive index layer or medium refractive index layer is a vapor deposition film of an inorganic oxide having a high refractive index such as titanium oxide or zirconium oxide formed by a vapor deposition method such as chemical vapor deposition (CVD) or physical vapor deposition (PVD). Alternatively, a coating film in which inorganic oxide fine particles having a high refractive index such as titanium oxide are dispersed can be obtained.

Antifouling layer 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 preferably the light-transmitting substrate having the low refractive index layer formed thereon It is preferable that an antifouling layer is provided on the side opposite to one side. The antifouling layer can further improve the antifouling property and scratch resistance with respect to the antireflection laminate.
Specific examples of the antifouling layer agent include fluorine compounds that have low compatibility with ionizing radiation curable resin compositions having fluorine atoms in the molecule and are difficult to add to the low refractive index layer, and Examples thereof include silicon compounds, ionizing radiation curable resin compositions having fluorine atoms in the molecule, and fluorine compounds and / or siliceous compounds having compatibility with fine particles.

2. Method for producing optical laminate
Adjustment of composition for each layer The composition for each layer forming the antiglare layer, the low refractive index layer, and the like may be adjusted by mixing and dispersing the components described above according to a general preparation method. For mixing and dispersing, it is possible to appropriately disperse with a paint shaker or a bead mill.

Specific examples of the coating method of each liquid composition on the surface of the coated light transmissive substrate and the surface of the antistatic layer include dip coating, air knife coating, curtain coating, roll coating, and wire bar coating. , Gravure coating method, extrusion coating method, micro gravure coating method, roll coating method, extrusion method, spin coating method, spray method, slide coating method, bar coating method, meniscus coater method, flexographic printing method, screen printing method, Various methods such as a peade coater method can be used.

A well-known method can be used as a method of curing the resin constituting each cured layer. For example, in the case of an electron beam curable resin, 50 to 1000 KeV emitted from various electron beam accelerators such as a Cockrowalton type, a bandegraph type, a resonant transformation type, an insulating core transformer type, a linear type, a dynamitron type, and a high frequency type. Preferably, an electron beam having an energy of 100 to 300 KeV is used, and in the case of ultraviolet curing, ultraviolet rays emitted from light such as an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a xenon arc, a metal halide lamp, etc. are used. it can.

3. Use of optical laminate The optical laminate according to the present invention is preferably used as an antireflection laminate. Moreover, the optical laminated body by this invention is utilized as a laminated body for display outermost surfaces of a polarizing plate and a transmissive display apparatus. In particular, it is used for display displays of televisions, computers, word processors and the like. In particular, it is used on the surface of displays such as CRTs and liquid crystal panels.

A polarizing plate is mainly composed of two protective laminates sandwiching a polarizing film from both sides. The antireflection laminate of the present invention is preferably used for at least one of the two protective laminates sandwiching the polarizing film from both sides. The manufacturing cost of a polarizing plate can be reduced because the optical laminated body of this invention serves as a protective laminated body. Moreover, by using the optical layered body of the present invention for the outermost layer, reflection of external light and the like can be prevented, and a polarizing plate having excellent scratch resistance, antifouling property and the like can be obtained. As the polarizing film, a known polarizing film or a polarizing film cut out from a long polarizing film whose absorption axis is neither parallel nor perpendicular to the longitudinal direction may be used.

  The contents of the present invention will be described in detail by the following examples, but the contents of the present invention should not be construed as being limited to the contents of the examples. The numerical value represents mass (kg) unless otherwise defined.

A light transmissive substrate cellulose triacetate film (trade name: T80UZ, manufactured by Fuji Photo Film) was prepared.

Preparation of Antiglare Layer Composition An antiglare layer composition was prepared by mixing according to the composition shown in Table 1 below.

Table 1

Polystyrene beads 16.0
(Made by Soken Chemical Co., Ltd .: SX-350H)
Pentaerythritol acrylate 94.0
(Nippon Kayaku Co., Ltd.)
Dipentaerythritol pentaacrylate 5.0
(Nippon Kayaku Co., Ltd.)
Acrylic polymer 10.0
(Made by Inktec)
Irgacure 184 6.6
(Polymerization initiator: manufactured by Ciba-Gaiky)
Irgacure 907 1.1
(Polymerization initiator: manufactured by Ciba-Gaiky)
Silicon 10-28 0.59
(Daiichi Seika Co., Ltd. (solid content 10%))
Gold and nickel plated organic beads 0.15
(Bright 20GNR-4.6EH)
Solvent 1: Toluene 116
Solvent 2: Cyclohexanone 67
37.5% solids

Preparation of Composition for Antistatic Layer Compositions 1 to 3 for antistatic layer were prepared by mixing according to the composition shown in Table 2 below.

Table 2
Composition 1 Composition 2 Composition 3
ATO particles 0.725 0.725 0.725
(ATO: antimony-doped tin oxide)
Urethane acrylate 0.375 0.375 0.375
Ethyl cellosolve 1.375 1.375 1.375
(Pertron C-4456S-7 manufactured by Nippon Pernox)
KS-HDDA 1.53 0.65 0.65
(Nippon Kayaku Co., Ltd.)
Irgacure 184 0.084 0.084 0.084
(Cibagayki)
Solvent 1: Methyl ethyl ketone 6.1 6.1 5.9
Solvent 2: Cyclohexanone 2.4 2.4 2.4
Solid content (%) 21.5 15.7 15.7

Example 1
The antistatic layer composition 1 is applied to one side of a cellulose triacetate film (thickness: 80 μm) using a Miya bar, and held in a heat oven at a temperature of 50 ° C. for 1 minute, and then the ultraviolet light has an integrated light quantity of 35 mj-35 mj. Thus, the coating film was cured by irradiation to form an antistatic layer having a coating amount of 1.0 g / cm ² (during drying). Next, the anti-glare layer composition is applied onto the formed antistatic layer using a Miya bar, and after being held in a thermal oven at a temperature of 50 ° C. for 1 minute, the cumulative amount of ultraviolet light becomes 12 mj-35 mj. The coating was cured by irradiation as described above to form an antiglare layer having a coating amount of 7.0 g / cm ² (during drying) to prepare an optical laminate (antistatic antiglare laminate).

Comparative Example 1
An optical laminate was prepared in the same manner as in Example 1 except that the antistatic layer composition 1 was changed to the antistatic layer composition 2.

Comparative Example 2
An optical laminate was prepared in the same manner as in Example 1 except that the antistatic layer composition 1 was changed to the antistatic layer composition 3.

Comparative Example 3
An optical laminate was prepared in the same manner as in Example 1 except that the antistatic layer composition 1 was not formed.

Evaluation Test The optical laminate obtained in the above example was subjected to the following evaluation test and evaluated, and the results are shown in Table 3 below.

Evaluation 1: Total light transmittance Total light transmittance (%) was measured using a haze meter (manufactured by Murakami Color Research Laboratory, product number: HR-100).

Evaluation 2: Haze value The haze value (%) was measured using a haze meter (manufactured by Murakami Color Research Laboratory, product number: HR-100).

Evaluation 3: 60 degree glossiness It measured using the glossiness measuring device (Murakami Color Research Laboratory make, product number; GM-26D).

Evaluation 4: Reflection evaluation The optical layered body is bonded with a crossed Nicol polarizing plate, and a fluorescent lamp is reflected, and visually observed.
Judgment was made based on the following criteria.
Evaluation standard evaluation A: Almost no reflection of fluorescent light was observed.
Evaluation (circle): Although some reflection of a fluorescent lamp was seen, there is no problem in an optical characteristic.
Evaluation (triangle | delta): The reflection of a fluorescent lamp is seen and there is no problem as an optical laminated body product.

Evaluation 5: Surface glare evaluation A color filter was placed on the backlight, glass was pasted on the back surface of the optical layered body, the surface was observed on the color filter, and judged by the following criteria.

Evaluation Criteria Evaluation A: Almost no glare was observed.
Evaluation (circle): Although some glare was seen, there is no problem in an optical characteristic.
Evaluation (triangle | delta): The reflection of a fluorescent lamp is seen a little and there is no problem as an optical laminated body product.

Evaluation 6: Surface roughness measurement Using a surface roughness measuring instrument SE-3400 (Kosaka Laboratories), according to the measurement standard of JIS B0601-1994, the surface roughness of the optical laminate (planar area of 5 μm ² ) was measured. The thickness (Sm) and arithmetic average roughness (Ra) were measured.

Table 3
Evaluation Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3
Evaluation 1 89.6 89.6 89.6 90.8
Evaluation 2 37 37 37 34
Evaluation 3 40 28 33 50
Evaluation 4 ◎ ○ ○ △
Evaluation 5 ◎ △ △ ○
Evaluation 6 (Sm) 71 101 91 56
(Ra) 0.23 0.31 0.28 0.18

Sectional drawing of the optical laminated body of this invention is represented. 1 is a cross-sectional view of a preferred optical laminate of the present invention.

Claims (5)

An optical laminate comprising a light transmissive substrate, an antistatic layer on the light transmissive substrate, and an antiglare layer in this order,
The light transmissive substrate is cellulose triacetate,
The antistatic layer is formed by applying a composition for an antistatic layer containing conductive fine particles, a permeable solvent, and an ionizing radiation curable resin on the light transmissive substrate. The antiglare layer is formed by applying a composition for an antiglare layer containing resin beads, a permeable solvent, and an ionizing radiation curable resin on the antistatic layer. ,
The light-transmitting substrate comprises the penetrating solvent and ionizing radiation curable resin contained in the antistatic layer composition, and the penetrating solvent and ionizing radiation curable resin contained in the antiglare layer composition. The ionizing radiation curable resin contained in the antistatic layer composition, the ionizing radiation curable resin contained in the antiglare layer composition, and the light-transmitting substrate. Ri name is a made by the permeation layer is formed,
An optical laminate having a thickness of the permeation layer of 0.1 μm or more and 1.5 μm or less . The osmotic solvent is acetone, ketone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, nitromethane, 1,4-dioxane, dioxolane, N-methylpyrrolidone, ethyl acetate, methyl acetate, butyl acetate, dichloromethane, trichloromethane, trichloroethylene, ethylene chloride, The optical laminate according to claim 1, which is one or a mixture of two or more selected from the group of trichloroethane, tetrachloroethane, N, N-dimethylformamide, and chloroform. The optical laminated body of Claim 1 or 2 utilized as an antireflection laminated body. A polarizing element, comprising an optical laminate according to any one of claims 1 to 3 polarizer. The optical laminated body as described in any one of Claims 1-3 utilized for an image display apparatus.

Images