JP2009229598A - Anti-reflection stack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anti-reflection stack which has a satisfactory antireflection characteristic and, at the same time, has hard surface hardness. <P>SOLUTION: The anti-reflection stack is prepared by laminating a low-refractive-index layer containing a thiol compound on a transparent substrate. The low-refractive-index layer contains fine particles and, further, contains fluorine polymer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an antireflection laminate.

  Conventionally, the surface of a display such as a liquid crystal display (LCD), a plasma display panel (PDP), or a cathode ray tube display (CRT) has a high surface hardness or a light beam irradiated from an external light source such as an incandescent lamp or a fluorescent lamp. An antireflection laminate such as an antireflection film is provided in order to impart antireflection characteristics for preventing reflection. Usually, an antireflection film has a structure in which a hard coat layer and a refractive index control layer are laminated on a transparent substrate, and the refractive index control layer has a lower refractive index in order to contribute to antireflection. It is preferable that it is a rate. As a method for achieving a low refractive index, for example, a method of forming a refractive index control layer by laminating layers having different refractive indexes, such as a low refractive index layer, a middle refractive index layer, and a high refractive index layer, as a thin film It has been known. For example, Patent Documents 1 and 2 disclose antireflection films in which specific fine particles are contained in the refractive index control layer. Furthermore, Patent Document 3 discloses an antireflection article using a fluorine-containing material that exhibits a low refractive index in the refractive index control layer, and Patent Document 4 discloses a co-polymer containing a fluorine-containing compound or a fluorine-containing vinyl monomer. What applied the polymer to the refractive index control layer as a film forming composition is disclosed.

However, in the antireflection film disclosed in Patent Documents 1 and 2, when a large amount of fine particles are used in order to lower the refractive index, the ratio of the binder resin constituting the refractive index control layer becomes small, and the control layer There was a problem that the hardness of the steel markedly decreased. In addition, the antireflective article disclosed in Patent Document 3 described above, when a large amount of fluorine-containing material is used to lower the refractive index, the crosslinking reaction does not proceed sufficiently due to the low reactivity, and the control layer The film-forming composition disclosed in Patent Document 4 has a problem in that poor crosslinking and curing due to incompatibility with the binder resin constituting the control layer occurs. was there.
Thus, the low refractive index (antireflection characteristic) and high surface hardness are contradictory characteristics, and an antireflection laminate having these at the same time at a high level has been desired.
JP 2003-75605 A JP 2005-99778 A Japanese Patent No. 3017595 JP 2005-196122 A

  Under such circumstances, an object of the present invention is to provide an antireflection laminate having a high surface hardness while having good antireflection properties.

  As a result of intensive studies to achieve the above object, the present inventors have found that the above problem can be solved by using a thiol compound in a low refractive index layer provided on a transparent substrate. The present invention has been completed based on such findings.

That is, the present invention
(1) An antireflective laminate formed by laminating a low refractive index layer containing a thiol compound on a transparent substrate,
(2) The antireflective laminate according to (1) above, wherein the low refractive index layer further contains fine particles, and (3) the above (1) or (2), wherein the low refractive index layer further contains a fluoropolymer. An antireflective laminate according to claim 1,
Is to provide.

  According to the present invention, it is possible to obtain an antireflection laminate having a high surface hardness while having good antireflection properties.

The antireflection laminate of the present invention is formed by laminating a low refractive index layer containing a thiol compound on a transparent substrate. The antireflection laminate of the present invention will be described with reference to FIG. FIG. 1 is a schematic view showing a cross section of one example of a preferred layer configuration of the antireflection laminate of the present invention. The antireflective laminate 1 shown in FIG. 1 has a low refractive index layer 3 laminated on a transparent substrate 2, and is hard from the transparent substrate 2 side between the transparent substrate 2 and the low refractive index layer 3. The coat layer 4, the middle refractive index layer 5, and the high refractive index layer 6 are laminated in order. The layer configuration of the antireflection laminate 1 of the present invention is not particularly limited as long as the low refractive index layer 3 is laminated on the transparent substrate 2, and for example, transparent substrate / low refractive index layer, transparent Substrate / hard coat layer / low refractive index layer, transparent substrate / hard coat layer / medium refractive index layer / high refractive index layer / low refractive index layer, transparent substrate / hard coat layer / high refractive index layer / medium refraction Examples thereof include a refractive index layer / low refractive index layer, transparent substrate / medium / high refractive index layer / low refractive index layer, and the like. These antireflection laminates 1 may be provided with an antistatic layer. In the above-described layer configuration, the antireflection laminate 1 is usually provided in any layer between the transparent substrate and the low refractive index layer.
Hereinafter, the transparent substrate 2 will be described in order.

[Transparent substrate 2]
The transparent substrate 2 used in the present invention is not particularly limited as long as it is a transparent material generally used as a substrate for an antireflection film, but preferably a plastic film, a plastic sheet or the like is appropriately selected depending on the application. be able to.

  Examples of such a plastic film or plastic sheet include those made of various synthetic resins. Synthetic resins include low density polyethylene resins (including linear low density polyethylene resins), medium density polyethylene resins, high density polyethylene resins, ethylene α-olefin copolymers, polypropylene resins, polymethylpentene resins, polybutene resins, ethylene- Polyolefin resins such as propylene copolymer, propylene-butene copolymer, olefinic thermoplastic elastomer or mixtures thereof; polyethylene terephthalate resin (PET), polybutylene terephthalate resin, polyethylene naphthalate-isophthalate copolymer resin, polyester Polyester resins such as thermoplastic elastomers; acrylic resins such as poly (meth) acrylic acid methyl resin, poly (meth) ethyl acrylate resin, poly (meth) butyl acrylate resin; Polyamide resin represented by 6 or nylon 66; cellulose resin such as triacetyl cellulose resin (TAC), diacetyl cellulose, acetate butyrate cellulose, cellophane; polystyrene resin; polycarbonate resin; polyarylate resin; or polyimide resin Can be mentioned.

The transparent substrate 2 can be used alone or in the form of a mixture of two or more of the plastic films and plastic sheets described above. From the viewpoint of flexibility, toughness, transparency, and the like, polyethylene terephthalate A resin and a triacetyl cellulose resin are preferred.
Although there is no restriction | limiting in particular about the thickness of the transparent base material 2, Usually, it is about 25-1000 micrometers, and when durability, handling property, etc. are considered, 40-80 micrometers is preferable.

[Low refractive index layer 3]
The low refractive index layer 3 in the present invention contains a thiol compound as an essential component and is formed of an optional component such as a binder resin as necessary.
The low refractive index layer 3 is a layer having a refractive index of 1.5 or less, and the lower the refractive index, the better. However, in consideration of the balance between antireflection characteristics and surface hardness, 1.25 to 1.45 is Preferably, 1.25 to 1.35 is more preferable. This refractive index can be easily controlled by the content of the thiol compound, the use of the fluoropolymer, the use amount thereof, or the like.
The thickness of the low refractive index layer 3 varies depending on the desired refractive index, but is preferably about 100 to 120 nm from the viewpoint of reducing the reflectance in the visible light region.

[Thiol compound]
The thiol compound used for the low refractive index layer 3 is not particularly limited as long as it is an organic compound having a thiol group, but is preferably a compound represented by the following general formula (1).

In General Formula (1), R ¹ represents a carbon atom, a monovalent to trivalent hydrocarbon group, or a group represented by General Formula (6).

n represents the valence of R ¹ , and 4 when R ¹ is a carbon atom. As the monovalent hydrocarbon group, R ⁴ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkenyl group, a cycloalkyl group having 3 to 10 carbon atoms, a cycloalkenyl group, an aryl group having 6 to 10 carbon atoms, Examples include aralkyl groups having 7 to 10 carbon atoms. Examples of the divalent hydrocarbon group include an alkanediyl group having 2 to 10 carbon atoms, a cycloalkenediyl group having 3 to 10 carbon atoms, a cycloalkanediyl group, a cycloalkenediyl group, an arenediyl group having 6 to 10 carbon atoms, carbon Examples include aralkanediyl groups of several 7 to 10. These groups may have a branched chain or may be substituted. The trivalent hydrocarbon group includes an alkanetriyl group having 2 to 10 carbon atoms, an alkenetriyl group, a cycloalkanetriyl group having 3 to 10 carbon atoms, a cycloalkenetriyl group, and an arene having 6 to 10 carbon atoms. A triyl group, a C7-10 aralkylcantriyl group, etc. are mentioned. These groups may have a branched chain or may be substituted.

In general formula (1), R ² represents a hydrogen atom, a monovalent hydrocarbon group, or a group represented by the following general formula (2). A plurality of R ² may be the same or different, and at least one of them is a group represented by the general formula (2). Examples of the monovalent hydrocarbon group are the same as the monovalent hydrocarbon in R ¹ described above.

In general formula (2), R ³ represents a hydrogen atom or a group represented by any one of general formulas (3) to (5). A plurality of R ³ may be the same or different, and at least one of them is a group represented by the general formula (3) or (4).
In General Formula (3), R ⁴ represents a hydrogen atom or a monovalent hydrocarbon group, and a plurality of R ⁴ may be the same or different. In General Formula (4), R ⁵ represents a hydrogen atom or a monovalent hydrocarbon group, and a plurality of R ⁵ may be the same or different. Examples of the monovalent hydrocarbon group in R ⁴ and R ⁵ are the same as the monovalent hydrocarbon in R ¹ described above. p is 1 or 2, q is an integer of 0 to 2, r is 0 or 1, s is an integer of 0 to 2, t is 0 or 1, and a plurality of p, q, r, and s are the same or different. May be. In general formula (5), x represents 1 or 2, and R ² is the same as above. A plurality of x may be the same or different.

  Among the thiol compounds represented by the above general formula, 1,4-bis (3-mercaptobutyryloxy) butane ("" manufactured by Showa Denko KK, from the viewpoint of obtaining good antireflection properties and surface hardness. Karenz MT BD1 (trade name)), pentaerythritol tetrakis (3-mercaptobutyrate) ("Karenz MT PE1 (trade name)"), 1,3,5-tris (3-mercaptobutyloxyethyl) -1, 3,5-triazine-2,4,6 (1H, 3H, 5H) -trione ("Karenz MT NR1 (trade name)") or trimethylolpropane (3-mercaptopropionate) manufactured by Sakai Chemical Industry Co., Ltd. ) ("TMMP (trade name)"), pentaerythritol tetrakis (3-mercaptopropionate) ("PEMP (trade name)"), di Pentaerythritol hexakis (3-mercaptopropionate) ( "DPMP (trade name)"), tris [(3-mercapto-propionyl b carboxymethyl) - ethyl] isocyanurate ( "TEMPIC (trade name)") and the like are preferable.

  0.1-10 mass% is preferable, as for content of the thiol compound in the low-refractive-index layer 3, 0.1-7.5 mass% is more preferable, and 1-5 mass% is further more preferable. When used in combination with a binder resin described later, the content of the thiol compound with respect to the total of the thiol compound and the binder resin is preferably 0.5 to 20% by mass, more preferably 1 to 15% by mass, and 2.5 to 12.5 mass% is more preferable. If the content of the thiol compound is within the above range, good surface hardness can be obtained and good transparency can be obtained without reducing the antireflection property. Moreover, when using together with binder resin, since it is within the said range and the quantity of binder resin is ensured, favorable surface hardness is obtained.

[Fine particles]
The low refractive index layer 3 can preferably further contain fine particles for the purpose of reducing its refractive index, that is, for the purpose of improving the antireflection characteristics. The fine particles can be used without limitation whether they are inorganic or organic. From the viewpoint of improving the antireflection properties and ensuring good surface hardness, the fine particles themselves have voids. Preferably used.
Fine particles having voids themselves have fine voids on the outside and inside, and are filled with a gas such as air having a refractive index of 1, for example, so that the refractive index of the particles itself is low. ing. Examples of such fine particles having voids include inorganic or organic porous fine particles and hollow fine particles. For example, porous silica fine particles, hollow silica fine particles, porous polymer fine particles using acrylic resin, etc. Examples thereof include polymer fine particles. As the inorganic fine particles, silica fine particles having voids prepared by using the technique disclosed in Japanese Patent Laid-Open No. 2001-233611 are used. As organic fine particles, the technique disclosed in Japanese Patent Laid-Open No. 2002-80503 is disclosed. A hollow polymer fine particle prepared by using, for example, can be mentioned as a preferred example.

Further, as the fine particles, fine particles capable of forming a nanoporous structure in at least a part of the inside and / or the surface depending on the form, structure, aggregated state, and dispersed state in the film are also preferable.
Such fine particles are produced for the purpose of increasing the specific surface area of the above-mentioned silica fine particles, and are used for the release column for absorbing various chemical substances in the packing column and the porous portion of the surface, and for fixing the catalyst. Examples thereof include porous fine particles used, and dispersions and aggregates of hollow fine particles intended to be used for heat insulating materials and low dielectric materials. Specific examples include “Nipsil (trade name)”, “Nipgel (trade name)” manufactured by Nippon Silica Industry Co., Ltd., “Colloidal Silica UP Series (trade name)”: Nissan Chemical Industries, Ltd., and the like. .

The average particle size of the fine particles is preferably 5 to 200 nm, more preferably 5 to 100 nm, and still more preferably 10 to 80 nm. When the average particle size of the fine particles is within the above range, the transparency of the low refractive index layer 3 is not impaired, and a good dispersed state of the fine particles can be obtained.
10-95 mass% is preferable, as for content of the microparticles | fine-particles in the low-refractive-index layer 3, 20-70 mass% is more preferable, and 30-70 mass% is further more preferable. If the content of the fine particles is within the above range, good antireflection characteristics and surface hardness can be obtained.

[Fluoropolymer]
The low refractive index layer 3 can further preferably contain a fluoropolymer in order to lower its refractive index. Examples of the fluoropolymer include polytetrafluoroethylene, tetrafluoroethylene-perfluoro (alkyl vinyl ether) copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, ethylene-tetrafluoroethylene copolymer, polyvinylidene fluoride, poly Preferred are chlorotrifluoroethylene and the like. Among them, those having a hydrophilic group and a crosslinking group and having a number average molecular weight of 10,000 or more are preferred. Such a fluoropolymer is easily available as a commercial product, and examples thereof include functional group-containing fluororesin “Obtool AR-110 (trade name)” manufactured by Daikin Industries, Ltd.
1-40 mass% is preferable, as for content of the fluoropolymer in the low-refractive-index layer 3, 5-35 mass% is more preferable, and 10-30 mass% is further more preferable. Moreover, when using together with the binder resin mentioned later, it is preferable that content with respect to the sum total of the fluoropolymer of a fluoropolymer and binder resin shall be about 50-80 mass%, and 50-70 mass% is more preferable. By setting the content of the fluoropolymer within the above range, it is possible to maintain a practically strong strength while achieving a low refractive index due to fluorine atoms.

[Binder resin]
The low refractive index layer 3 preferably contains a binder resin from the viewpoints of film formability and film strength. As the binder resin, the above-mentioned thiol compound, fine particles added as necessary, fluoropolymer, etc. are applied to the layer of the low refractive index layer 3 by irradiation with ionizing radiation such as ultraviolet rays or electron beams. A resin that can be fixed by crosslinking and curing is preferred. More specifically, examples of the binder resin include thermosetting resins such as melamine type, urea type, epoxy type, ketone type, diallyl phthalate type, unsaturated polyester type, and phenol type, and ionizing radiation curable resin. Is mentioned. Among these, ionizing radiation curable resins are preferable.

  The ionizing radiation curable resin refers to a resin having an energy quantum capable of crosslinking and polymerizing molecules in an electromagnetic wave or a charged particle beam, that is, a resin that is crosslinked and cured by irradiation with ultraviolet rays or electron beams. Specifically, it can be appropriately selected from polymerizable monomers and polymerizable oligomers (or prepolymers) conventionally used as ionizing radiation curable resins.

As the polymerizable monomer, a (meth) acrylate monomer having a radical polymerizable unsaturated group in the molecule is suitable, and among them, a polyfunctional (meth) acrylate is preferred.
The polyfunctional (meth) acrylate is not particularly limited as long as it is a (meth) acrylate having two or more ethylenically unsaturated bonds in the molecule. Specifically, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, pentaerythritol di (meth) acrylate monostearate, dicyclopentanyl di (meth) acrylate, isocyanurate di (meth) acrylate, etc. Di (meth) acrylate; tri (meth) acrylate such as trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, tris (acryloxyethyl) isocyanurate; dipentaerythritol tetra (meth) acrylate, dipenta Tetrafunctional or higher functional (meth) acrylates such as erythritol penta (meth) acrylate and dipentaerythritol hexa (meth) acrylate; N'okishido modified products, caprolactone modified products, and the like propionic acid-modified products. These polyfunctional (meth) acrylates may be used singly or in combination of two or more.

  In the present invention, a monofunctional (meth) acrylate can be used in combination with the above-described polyfunctional (meth) acrylate as long as the object of the present invention is not impaired for the purpose of reducing the viscosity. .

Next, as the polymerizable oligomer, an oligomer having a radically polymerizable unsaturated group in the molecule, for example, epoxy (meth) acrylate, urethane (meth) acrylate, polyester (meth) acrylate, polyether (meth) Examples include acrylate oligomers.
Furthermore, other polymerizable oligomers include polybutadiene (meth) acrylate oligomers with high hydrophobicity that have (meth) acrylate groups in the side chain of polybutadiene oligomers, and silicone (meth) acrylate oligomers that have polysiloxane bonds in the main chain. In a molecule such as an aminoplast resin (meth) acrylate oligomer modified with an aminoplast resin having many reactive groups in a small molecule, or a novolak type epoxy resin, bisphenol type epoxy resin, aliphatic vinyl ether, aromatic vinyl ether, etc. There are oligomers having a cationic polymerizable functional group.

The polymerizable oligomer preferably has a number average molecular weight (polystyrene equivalent number average molecular weight measured by GPC method) of 20000 or less. By using such a polymerizable oligomer, the viscosity can be lowered and the coating suitability can be improved.
Such an oligomer is easily available as a commercial product. Examples of commercially available products include “epoxy ester (trade name): manufactured by Kyoeisha Chemical Co., Ltd.”, “epoxy (trade name): manufactured by Showa Polymer Co., Ltd., etc. Epoxy (meth) acrylate-based oligomers: “purple light (trade name)”; manufactured by Nippon Synthetic Chemical Industry Co., Ltd., “urethane acrylate (trade name)”; It is done.

The above-described polymerizable monomer and polymerizable oligomer have a large effect of increasing the cross-linking density of the low refractive index layer 3, so that the surface hardness can be improved and the fluidity (thixotropy) is high. Application suitability is high. These polymerizable monomers and polymerizable oligomers may be a reactive polymer having a (meth) acrylate group in the main chain or side chain and having a number average molecular weight of 20000 or more, or a perfluoropolyether in the main chain or side chain, if necessary. It can use preferably with the reactive polymer etc. which have the (meth) acrylate group containing fluorine components, such as. By using such a reactive polymer with a large number average molecular weight, the film formability, such as being able to follow complex shapes, is improved, and curling and warping of the antireflection laminate are suppressed when the binder resin is cured. It becomes possible to do.
Such a reactive polymer is obtained by, for example, polymerizing methyl methacrylate and glycidyl methacrylate in advance to obtain a copolymer, and then condensing the glycidyl group of the copolymer with the carboxyl group of methacrylic acid or acrylic acid. Obtainable. The reactive polymer is readily available as a commercial product, and examples of the commercial product include “macromonomer (trade name)” manufactured by Toagosei Co., Ltd.

  In the present invention, an ultraviolet curable resin or an electron beam curable resin can be preferably used as the ionizing radiation curable resin. An electron beam curable resin is more preferable because it does not require a photopolymerization initiator and stable curing characteristics can be obtained, but an ultraviolet curable resin can also be used without any trouble when used in combination with a photopolymerization initiator described later. .

When using an ultraviolet curable resin as the ionizing radiation curable resin, the photopolymerization initiator is based on 100 parts by mass of the ultraviolet curable resin component in which the thiol compound, the ultraviolet curable resin, and the fluoropolymer are combined. It is preferable to add about 0.5-10 mass parts, and the addition of 3-5 mass parts is more preferable. The photopolymerization initiator can be appropriately selected from those conventionally used, and is not particularly limited. For example, for a polymerizable monomer or polymerizable oligomer having a radical polymerizable unsaturated group in the molecule. And photopolymerization initiators such as acetophenone, benzophenone, benzoin, ketal, anthraquinone, disulfide, thioxanthone, thiuram, and fluoroamine. Of these, acetophenone and benzophenone are preferable, and 2-hydroxy-1-{(4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] -phenyl) -2-methyl-propane-1- ON, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one and the like are more preferable. Hydroxy-1-{(4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] -phenyl) -2-methyl-propan-1-one has a wide ultraviolet absorption wavelength range and radical generation efficiency Is very high, and the reactivity is high, so that a low refractive index layer excellent in surface hardness can be obtained, which is particularly preferable. These photoinitiators may be used individually by 1 type, and may be used in combination of 2 or more type.
Further, 2-hydroxy-1-{(4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] -phenyl) -2-methyl-propan-1-one is employed as a photopolymerization initiator. In this case, the above-mentioned other polymerization initiator can be used in an amount of preferably 1 to 5 parts by mass, more preferably 1 to 3 parts by mass with respect to 10 parts by mass of the photopolymerization initiator. Examples of the other polymerization initiator used in combination include those described above, among which 1-hydroxycyclohexylphenyl-ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propane- 1-one, benzyldimethylketone, 1- (4-dodecylphenyl) -2-hydroxy-2-methylpropan-1-one, benzophenone, benzoin and the like are preferable.

When the ionizing radiation curable resin is adopted as the binder resin, the low refractive index layer 3 preferably contains an organically modified silicone oil. The organically modified silicone oil is added mainly for the purpose of imparting surface properties such as stain resistance to the antireflection laminate of the present invention due to a synergistic effect with the ionizing radiation curable resin.
Examples of the organic functional group used for organic modification include (meth) acryl group, amino group, silanol group, fluoroalkyl group, mercapto group, carboxyl group and the like, among which (meth) acryl group, amino group, silanol group are The organic modified silicone oil preferably has 1 to 6 such organic functional groups because it is excellent in the balance between the compatibility with other components in the low refractive index layer 3 and the obtained surface hardness. Those are preferred.
The structure of organically modified silicone oils is roughly divided into side chain type, double-ended type, single-ended type, and double-ended side chain type depending on the bonding position of the organic functional group to be substituted. The position is not particularly limited.

  The amount of the organically modified silicone oil added is from 0.3 to 100 parts by mass with respect to 100 parts by mass of all components other than the silicone oil constituting the low refractive index layer 3 from the viewpoint of sufficiently improving the stain resistance and obtaining the effect of use. 8 parts by mass is preferable, and 1 to 5 parts by mass is more preferable. Moreover, as a functional group equivalent (molecular weight / functional group number) of a silicone (meth) acrylate, a thing about 100-20000 normally, Preferably what has the conditions of 100-10000 is mentioned.

  Various additives are blended in the low refractive index layer 3 in accordance with desired physical properties. Examples of the additive include a weather resistance improver, an abrasion resistance improver, a polymerization inhibitor, a crosslinking agent, an infrared absorber, an antistatic agent, an adhesion improver, an antioxidant, a leveling agent, a thixotropic agent, and a cup. A ring agent, a plasticizer, an antifoaming agent, a filler, a solvent, etc. are mentioned.

[Formation of Low Refractive Index Layer 3]
An example of a preferable method for forming the low refractive index layer 3 will be described below.

[Preparation of low refractive index layer-formed coating]
First, a thiol compound, a binder resin, fine particles added as needed, and various additives are homogeneously mixed at a predetermined ratio, and dissolved in a solvent as necessary to form a low refractive index layer. Prepare the product. The low refractive index forming coated material is preferably in a liquid form dissolved in a solvent in consideration of productivity. The viscosity of the liquid low-refractive index layer-formed coating material is not particularly limited as long as it is a viscosity capable of forming an uncured resin layer on the surface of the substrate by a coating method described later.

  Although it does not specifically limit as a solvent preferably used for low refractive index layer formation coating material, For example, Alcohols, such as methanol, ethanol, isopropyl alcohol (IPA); Ketones, such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone; Acetic acid Examples thereof include esters such as ethyl and butyl acetate; halogenated hydrocarbons; aromatic hydrocarbons such as toluene and xylene, or a mixture thereof. Among these, ketone organic solvents are preferable. When ketones are used, the coatability of the low refractive index layer-formed coating is improved, and the evaporation rate of the solvent after coating is moderate, so drying unevenness is unlikely to occur, and a large-area coating with a uniform thickness is applied. A film (low refractive index layer 3) can be easily obtained.

  The amount of the solvent is appropriately adjusted so that each component can be uniformly dissolved and dispersed, and does not agglomerate during storage after preparation of the coated product, and does not become too dilute during coating. 50-99.5 mass% is preferable and, as for content of the solvent in a low refractive index layer formation coating material, it is preferable to set it as 70-97 mass%. By setting it as such content, the coating material which is excellent in especially dispersion stability and suitable for long-term storage is obtained.

[Coating and curing of low-refractive-index layer-formed coatings]
Gravure coating, bar coating, roll coating, and reverse roll are applied to the surface of the transparent substrate 2 so that the thickness after curing of the low refractive index layer-formed coating material thus prepared becomes a predetermined thickness. It coats by well-known systems, such as a coat and a comma coat, preferably a gravure coat, and forms an uncured resin layer.
The uncured resin layer thus formed is dried for the purpose of evaporating the solvent, etc., and then heated or irradiated with ionizing radiation such as an electron beam or ultraviolet ray to cure the uncured resin layer. The refractive index layer 3 is obtained.

When an electron beam is used as the ionizing radiation when the uncured resin layer is cured, the acceleration voltage can be appropriately selected according to the resin used and the thickness of the layer. However, the acceleration voltage is usually about 70 to 300 kV. It is preferable to cure the cured resin layer.
In addition, in electron beam irradiation, the transmission capability increases as the acceleration voltage increases, so when using a base material that deteriorates due to the electron beam as the base material, the penetration depth of the electron beam and the thickness of the uncured resin layer By selecting an accelerating voltage so as to be substantially equal, it is possible to suppress the irradiation of the extra electron beam to the base material, and to minimize the deterioration of the base material due to the excess electron beam. it can.

The irradiation dose is preferably such that the crosslinking density of the curable resin in the surface shaping layer is saturated, and is usually selected in the range of 5 to 300 kGy (0.5 to 30 Mrad), preferably 10 to 50 kGy (1 to 5 Mrad). .
Further, the electron beam source is not particularly limited. For example, various electron beam accelerators such as a cockroft Walton type, a bandegraft type, a resonant transformer type, an insulated core transformer type, a linear type, a dynamitron type, and a high frequency type. Can be used.
When ultraviolet rays are used as the ionizing radiation, those containing ultraviolet rays having a wavelength of 190 to 380 nm are emitted. There are no particular restrictions on the ultraviolet light source, and for example, high pressure mercury lamps, low pressure mercury lamps, metal halide lamps, carbon arc lamps, etc. are used.

  Moreover, the temperature condition of the drying performed for the purpose of evaporating the solvent and the like contained in the ionizing radiation curable resin composition is preferably in the range of room temperature to 55 ° C, more preferably room temperature to 50 ° C, and the drying time is 10 -120 seconds are preferable, and 30-90 seconds are more preferable. In addition, room temperature is about 20 degreeC normally.

  In this way, the low refractive index layer 3 thus formed is added with various additives to have various functions such as a so-called hard coat function, anti-fogging coat function, anti-fogging function having high hardness and scratch resistance. An antifouling coating function, an antiglare coating function, an antireflection coating function, an ultraviolet shielding coating function, an infrared shielding coating function, and the like can also be imparted.

[Hard coat layer 4]
The antireflection laminate 1 of the present invention can have a hard coat layer 4 for the purpose of improving the performance of surface hardness such as scratch resistance on the antireflection laminate 1. Here, the hard coat refers to a performance showing a hardness of “H” or higher in a pencil hardness test specified in JIS 5600-5-4: 1999.
The hard coat layer is preferably obtained by crosslinking and curing an ionizing radiation curable resin. The ionizing radiation curable resin for forming the hard coat layer 4 is appropriately selected from the ionizing radiation curable resins used for the binder resin described above. The photopolymerization initiator used when the ionizing radiation curable resin is an ultraviolet curable resin is also appropriately selected from those exemplified above. Moreover, the various additives used for the above-mentioned low refractive index layer-forming coating can be used in the same manner.

  The hard coat layer 4 preferably has a film thickness after curing in the range of 0.1 to 100 μm, and more preferably in the range of 0.8 to 20 μm. If the film thickness is within the above range, sufficient hard coat performance can be obtained, and it is difficult to break against external impacts. Moreover, in this invention, the hard-coat layer 4 may combine the function of the middle refractive index layer 5 or the high refractive index layer 6 which is demonstrated below.

[Medium Refractive Index Layer 5 and High Refractive Index Layer 6]
In the antireflection laminate 1 of the present invention, a medium refractive index layer 5 and a high refractive index layer 6 may be provided for the purpose of improving the antireflection performance. Here, the middle refractive index layer 5 and the high refractive index layer 6 need not be provided at the same time as described above as the aspect of the antireflection laminate 1, for example, FIG. 2 may be provided as a single layer as the medium-high refractive index layer 7.
The refractive index of the medium refractive index layer 5, the high refractive index layer 6 or the medium high refractive index layer 7 (hereinafter sometimes referred to as these refractive index layers) is arbitrarily set within the range of 1.5 to 2.00. can do. That is, the middle refractive index layer 5 has a refractive index higher than at least the low refractive index layer 3 described above and lower than the high refractive index layer 6, and the refractive index is relative. . The refractive indexes of the medium refractive index layer 5 and the high refractive index layer 6 are relative as described above, but the refractive index of the medium refractive index layer 5 is usually in the range of 1.5 to 1.8, and high The refractive index of the refractive index layer 6 is in the range of 1.65 to 2.0.

  These refractive index layers may be formed of a binder 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 having a predetermined refractive index (in parentheses indicate refractive index) include zinc oxide (1.90), titania (2.3-2.7), and ceria (1.95). , Tin-doped indium oxide (1.95), antimony-doped tin oxide (1.80), yttria (1.87), and zirconia (2.0). Moreover, as a binder resin, it selects from the above-mentioned binder resin suitably, and is used.

  The refractive index of the ultrafine particles is preferably higher than that of the binder resin. Since the refractive index of these refractive index layers 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, it is possible to form a refractive index layer having a predetermined refractive index by adjusting the addition ratio of the binder resin and the ultrafine particles. If the ultrafine particles are conductive, the refractive index layer formed using such ultrafine particles has antistatic properties. These refractive index layers are vapor-deposited films of an inorganic oxide having a high refractive index such as titania or zirconia formed by a vapor deposition method such as chemical vapor deposition (CVD) or physical vapor deposition (PVD), or like titania. It is possible to form a film in which inorganic oxide fine particles having a high refractive index are dispersed.

  The film thickness of these refractive index layers is preferably in the range of 10 to 300 nm, and more preferably in the range of 30 to 200 nm. The above refractive index layer (medium refractive index layer, high refractive index layer, or medium high refractive index layer) may be provided directly on the transparent substrate 2, but the hard coat layer 4 is provided on the transparent substrate 2, and the hard coat layer 4 is provided. And the low refractive index layer 3 are preferably provided.

[Antistatic layer]
In the antireflection laminate 1 of the present invention, an antistatic layer may be provided for the purpose of suppressing the generation of static electricity, eliminating the adhesion of dust, and suppressing electrostatic damage from the outside.
The antistatic agent used in the antistatic layer is not particularly limited, and ion conductive materials, electronic conductive materials, inorganic fine particles, and the like are used. Examples of the antistatic agent include various cationic antistatic agents having a cationic group such as a quaternary ammonium salt, a pyridinium salt, and first to third amino groups; a sulfonate group, a sulfate ester base, and a phosphate ester. Anionic antistatic agents having anionic groups such as bases and phosphonic acid groups; amphoteric antistatic agents such as amino acids and aminosulfuric acid esters; nonionic antistatic agents such as amino alcohols, glycerols and polyethylene glycols Various surfactant type antistatic agents such as organometallic compounds such as tin and titanium alkoxides and metal chelate compounds such as acetylacetonate salts thereof; and polymers obtained by increasing the molecular weight of the above-mentioned antistatic agents Type antistatic agent. In addition, a tertiary amino group, a quaternary ammonium group, a monomer or oligomer having a metal chelate moiety and polymerizable by ionizing radiation, and an organometallic compound such as a coupling agent having a functional group polymerizable by ionizing radiation A polymerizable antistatic agent such as can also be used.

  Examples of the antistatic agent include inorganic oxide ultrafine particles having a particle diameter of 100 nm or less, such as tin oxide, tin-doped indium oxide (ITO), antimony-doped tin oxide (ATO), indium-doped zinc oxide (AZO), antimony oxide, Indium oxide or the like can also be used. In particular, when the particle size is 100 nm or less which is not more than the wavelength of visible light, the film becomes transparent after film formation, and the transparency of the antireflection film is not impaired.

  The antistatic layer may be provided directly on the transparent substrate 2, but the same effect can be obtained by dispersing the above-described antistatic agent in the hard coat layer 4 and each refractive index layer. The thickness of the antistatic layer is preferably in the range of 30 nm or less from the viewpoint of not affecting the antireflection performance. The antistatic layer can be formed in the same manner as each of the refractive index layers described above.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by this example.

(Evaluation methods)
1. Minimum reflectance (evaluation of antireflection characteristics)
About the laminated body obtained by each Example and the comparative example, using the spectrophotometer ("UV-3100PC (model number)": Shimadzu Corporation Corp.) provided with the regular reflection measuring apparatus, the minimum value in wavelength 550nm is the lowest. The reflectance was used. A smaller minimum reflectance indicates that the laminate has superior antireflection properties.
2. Evaluation of Transparency For the laminates obtained in each Example and Comparative Example, the ratio of the difference between the haze value measured according to JIS K7361-1 and the haze value of the transparent substrate is 1.5%. Evaluated by whether there is.
3. Evaluation of surface hardness (abrasion resistance)
About the laminated body obtained by each Example and the comparative example, the steel wool (# 0000) was subjected to 10 reciprocating friction over a fixed load, and the result of visual observation was evaluated according to the following criteria.
◎: No scratches were observed ○: The number of scratches was 1 to 5 Δ: The number of scratches was 6 to 10 ×: The number of scratches was 11 or more Peeling: Low refraction Rate layer has peeled

Preparation Example 1: Preparation of Low Refractive Index Layer-Forming Coating Material 1 Components having the following composition were mixed at the following mass ratio to prepare a low refractive index layer-forming coating material 1.
Low refractive index layer forming coating 1
Pentaerythritol triacrylate (PETA): 9.5 parts by mass Thiol compound 1 ^{* 1} : 0.5 part by mass Hollow silica particle dispersion ^{* 2} : 75 parts by mass Photopolymerization initiator ^{* 3} : 0.5 part by mass Antifouling agent ^{* 4} : 0.5 parts by mass Methyl isobutyl ketone: 560 parts by mass * 1, “Karenz MT PE1 (trade name)”: manufactured by Showa Denko KK, pentaerythritol tetrakis (3-mercaptobutyrate)
* 2. The content of hollow silica particles in the dispersion is 20% by mass, and the content of solvent (methyl isobutyl ketone) is 80% by mass. Moreover, the average particle diameter of the hollow silica particles is 60 nm, and has a photocurable reactive group on the surface.
* 3, "Irgacure 127 (trade name)": Ciba Specialty Chemicals Co., Ltd. * 4, "X-22-164E (trade name)": Shin-Etsu Chemical Co., Ltd.

Preparation Example 2: Preparation of Hard Coat Layer-Forming Coated Product 1 Components of the following composition were mixed at the following mass ratio to prepare a hard coat layer-forming coated product 1.
Hard coat layer forming coating 1
Pentaerythritol triacrylate (PETA): 30 parts by weight Photopolymerization initiator ^{* 1} : 0.5 part by weight Methyl isobutyl ketone: 73.5 parts by weight * 1, the same as that used in the low refractive index forming coating 1 It is.

Example 1
A hard coat layer-forming coated product 1 is bar-coated on a triacetylcellulose (TAC) resin film having a thickness of 80 μm, dried at 50 ° C. for 1 minute, and after removing the solvent, an ultraviolet irradiation device (fusion UV) Using a light source H bulb manufactured by System Japan Co., Ltd., it was cured by irradiation with ultraviolet rays at an irradiation dose of 30 mJ / cm ² to obtain a hard coat layer having a thickness of about 10 μm.
Next, the low-refractive-index layer-formed coating material 1 prepared in Preparation Example 1 is bar-coated on the obtained hard coat layer, dried at 50 ° C. for 1 minute, and the solvent is removed. The antireflective laminate having a transparent base material / hard coat layer / low refractive index layer was obtained by curing with ultraviolet irradiation at 200 mJ / cm ² to form a low refractive index layer having a thickness of about 100 nm. The results obtained by evaluating the obtained antireflection laminate by the above evaluation method are shown in Table 1.

Examples 2-6, Comparative Example 1
In Example 1, an antireflection laminate was obtained in the same manner as in Example 1 except that the low refractive index layer-formed coated material 1 was replaced with the low refractive index layer coated material shown in Table 1. Table 1 shows the results of evaluating the obtained antireflection laminate.

Examples 7-12, Comparative Example 2
In Example 1, an antireflection laminate was obtained in the same manner as in Example 1 except that the low refractive index layer-formed coated product 1 was replaced with the low refractive index layer coated product shown in Table 2. The results of evaluating the obtained antireflection laminate are shown in Table 2.

＊１〜＊４，上記と同様である。
＊５，「カレンズＭＴ ＢＤ１（商品名）」：昭和電工株式会社製，１，４−ビス−（３−メルカプトブチリルオキシ）ブタン
＊６，「ＰＥＭＰ（商品名）」：堺化学工業株式会社製，ペンタエリスリトールテトラキス（３−メルカプトプロピオネート）

* 1 to * 4, same as above.
* 5, “Karens MT BD1 (trade name)”: Showa Denko K.K., 1,4-bis- (3-mercaptobutyryloxy) butane * 6, “PEMP (trade name)”: Sakai Chemical Industry Co., Ltd. Manufactured by Pentaerythritol Tetrakis (3-mercaptopropionate)

＊１〜＊３、＊５及び＊６，上記と同様である。
＊７，「ＡＲ−１１０（商品名）」：ダイキン工業株式会社
＊８，「ＫＦ８００８（商品名）」：信越化学株式会社製

* 1 to * 3, * 5 and * 6, as described above.
* 7, “AR-110 (trade name)”: Daikin Industries, Ltd. * 8, “KF8008 (trade name)”: manufactured by Shin-Etsu Chemical Co., Ltd.

  The antireflection laminates obtained in Examples 1 to 12 were excellent in all evaluations, and were shown to have high surface hardness while having good antireflection properties. In addition, the antireflection laminates obtained in Examples 7 to 12 using a fluoropolymer for the low refractive index layer have performance that is practically acceptable, although some surface hardness is reduced. And it was shown that it has the further outstanding antireflection characteristic. On the other hand, the laminate obtained in Comparative Examples 1 and 2 in which the low refractive index layer does not have a thiol compound was insufficient in terms of surface hardness.

  According to the present invention, it is possible to obtain an antireflection laminate having a high surface hardness while having good antireflection properties. The antireflection laminate of the present invention has a high surface hardness and prevents reflection by light rays irradiated from an external light source such as an incandescent lamp and a fluorescent lamp, and is used for a liquid crystal display (LCD) and a plasma display panel (PDP). ), And is preferably provided on the surface of a display such as a cathode ray tube display (CRT).

It is a schematic diagram which shows the cross section of the antireflection laminated body of this invention. It is a schematic diagram which shows the cross section of the antireflection laminated body of this invention.

Explanation of symbols

1. 1. Antireflection laminate 2. Transparent substrate Low refractive index layer 4. 4. Hard coat layer Medium refractive index layer 6. 6. High refractive index layer Medium to high refractive index layer

Claims (6)

  An antireflection laminate obtained by laminating a low refractive index layer containing a thiol compound on a transparent substrate. The antireflection laminate according to claim 1, wherein the thiol compound is a compound represented by the following general formula (1).

(In General Formula (1), R ¹ represents a carbon atom, a monovalent to trivalent hydrocarbon group, or a group represented by General Formula (6). N represents the valence of R ^1. , .R ² showing a 4 when the R ¹ carbon atom, a hydrogen atom, or different monovalent hydrocarbon group, or the same as. a plurality of R ² of a group represented by the following general formula (2) And at least one of them is a group represented by the general formula (2) In the general formula (2), R ³ is a hydrogen atom or any one of the general formulas (3) to (5). A plurality of R ³ may be the same or different, and at least one of them is a group represented by the general formula (3) or (4). , R ⁴ is a hydrogen atom, or a monovalent hydrocarbon group, in the plurality of R ⁴ may be the same or different. formula (4), R ⁵ is a hydrogen atom, or a monovalent hydrocarbon It shows the original, good .p be a plurality of R ⁵ the same or different from each other 1 or 2, q is an integer of 0 to 2, r is 0 or 1, s is an integer of 0 to 2, t is 0 or And a plurality of p, q, r and s may be the same or different, and in general formula (5), x represents 1 or 2, and R ² is the same as above. x may be the same or different.

  The antireflective laminate according to claim 1, wherein the low refractive index layer further contains fine particles.   The antireflection laminate according to claim 3, wherein the fine particles are fine particles having voids.   The antireflective laminate according to any one of claims 1 to 4, wherein the low refractive index layer further contains a fluoropolymer.   The antireflection laminate according to claim 5, wherein the fluoropolymer has a number average molecular weight of 10,000 or more having a hydrophilic group and a crosslinking group.

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