JP2007216610A - Antireflective film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antireflective film which is excellent in scratch resistance and optical characteristic, and capable of being manufactured with high productivity by a wet type coating method. <P>SOLUTION: The antireflective film is made of a curable resin containing a multi-functional (meth)acrylate compound and fine particles composed of at least one kind of compound selected from the group of titanium oxide, zinc oxide, cerium oxide, zirconium oxide, indium-containing tin oxide, antimony-containing tin oxide, and zinc antimonic acid as a component, and a high refractive index layer having a refractive index of 1.55 to 1.65 is formed on a hard coat layer of a substrate film having a laminated hard coat layer on at least one side surface. After that, a low refractive index layer which is made of a curable resin containing a fluorine-containing polyolefin-based polymer which has a polysiloxane segment in a main chain, fluorine content of not less than 30 wt.%, and a number average molecular weight of not less than 5,000 in terms of polystyrene, and a cross-linking agent component as a component, and has a refractive index of 1.35 to 1.50 is laminated on the high refractive index layer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an antireflection film. More specifically, the antireflection film excellent in scratch resistance is suitably used as an antireflection film on the surface of a liquid crystal display (LCD), an organic EL display, a plasma display, and the like, and as a light transmittance increasing film inside the device. It is about.

  Many displays are used in an environment where external light is incident, whether indoors or outdoors. In recent flattened displays, incident external light is regularly reflected on the display surface, and a virtual image of external light is remarkably reproduced on the display screen of the display. For this reason, an image due to external light, for example, a fluorescent lamp, is reflected on the screen, and the visibility of the display image is deteriorated.

  Conventionally, an antireflection film in which an antireflection layer is formed on the surface of a transparent film substrate can be laminated on the outer surface of the display for the purpose of preventing the incidence of such external light on the display and at the same time improving the contrast of the screen. It is done. Such an antireflection film needs to prevent surface reflection and have sufficient scratch resistance.

  As such an antireflection film, a film obtained by forming a high refractive index layer containing a metal oxide or the like on the surface of a transparent film substrate and laminating a low refractive index layer is used. There are a wet method in which a coating layer is laminated by applying and drying the film on a substrate film, and a dry method in which the film is laminated by sputtering, vapor deposition, or the like. However, although the latter method can control the film thickness with high accuracy, the former method is becoming mainstream because of the problem of high production cost and low productivity due to the use of vacuum.

  As the low refractive material used here, for example, JP 2005-264064 A and JP 2005-239967 A propose a resin composition containing a fluorine-containing copolymer having a specific structure. On the other hand, as a high refractive material, for example, JP 2005-185924 A, JP 2005-187580 A, JP 2005-161111 A, and the like, a polymerizable resin containing titanium oxide particles or zirconium oxide particles having a high refractive index. Compositions have been proposed.

  However, in the combination of a conventional low refractive index layer using a fluorine-containing copolymer and a high refractive index layer using a polymerizable resin composition containing titanium oxide or zirconium oxide particles having a high refractive index, Adhesion is not sufficient, especially when repeatedly rubbed with a cloth or the like, there is a problem that the low refractive index layer is peeled off and the antireflection performance is lowered. As a method for solving this problem, Japanese Patent Application Laid-Open No. 8-94806 proposes an antireflection film in which fine particles are localized in the vicinity of an interface with a low refractive index layer in a high refractive index layer. However, the scratch resistance is still not sufficient, and further improvement is required for practical use.

JP 2005-264064 A JP 2005-239967 A JP 2005-185924 A JP 2005-187580 A Japanese Patent Laying-Open No. 2005-161111 JP-A-8-94806

  The present invention has been made in view of the above-described background art, and an object thereof is to provide an antireflection film that can be produced with high productivity by a wet coating method and that is excellent in scratch resistance and optical characteristics. .

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors combined specific hard coat layers, high refractive index layers, and low refractive index layers, and specified the surface roughness of the surface of the high refractive index layer. The present inventors have found that an antireflection film excellent in scratch resistance can be obtained, and as a result of further studies, have reached the present invention.

  Thus, according to the present invention, “a polyfunctional (meth) acrylate compound, titanium oxide, zinc oxide, cerium oxide, zirconium oxide, on a hard coat layer of a base film having a hard coat layer laminated on at least one side, It is made of a curable resin containing as constituent components fine particles made of at least one compound selected from the group consisting of indium-containing tin oxide, antimony-containing tin oxide and zinc antimonate, and has an average surface roughness (Ra) of 2 to 20 nm, 10 A high refractive index layer having a point average surface roughness (Rz) of 15 nm or more and a refractive index of 1.55 to 1.65 is formed, and then a polysiloxane segment in the main chain is formed on the high refractive index layer Fluorine-containing polyolefin system having a fluorine content of 30% by weight or more and a number average molecular weight in terms of polystyrene of 5000 or more A cured resin comprising a polymer and a crosslinking agent component as a constituent component, an anti-reflection film. "Is provided by forming a low refractive index layer with a refractive index 1.35 to 1.50.

  As a preferred embodiment, the fine particles in the high refractive index layer are fine particles having an average particle diameter of 5 to 20 nm made of antimony-containing tin oxide or zirconium oxide, and a high refractive index at the interface between the high refractive index layer and the low refractive index layer. The low refractive index layer component penetrates 10 to 30 nm in the layer, the crosslinking agent component of the low refractive index layer is a melamine compound, and the hard coat layer laminated on the base film is a polyfunctional (meth) acrylate And an antireflective film comprising at least one of a curable resin containing fine particles of at least one compound selected from the group consisting of silicon oxide, aluminum oxide, and silicone resin as constituent components Is done.

  The antireflection film of the present invention comprises a specific fluorine-containing polyolefin on a high refractive index layer having a specific surface roughness made of a curable resin containing a specific polyfunctional (meth) acrylate compound and fine particles as constituent components. Since a low refractive index layer containing a polymer and a crosslinker component as a constituent component is formed, it has excellent optical properties and scratch resistance. For example, an antireflection film on the surface of a liquid crystal display, an organic EL display, a plasma display, etc. Can be suitably used.

Hereinafter, the present invention will be described in detail.
The antireflection film of the present invention contains, as constituent components, fine particles comprising a specific compound described later and a polyfunctional (meth) acrylate compound on a hard coat layer of a base film having a hard coat layer laminated on at least one side. The high refractive index layer which consists of curable resin and has the specific surface roughness and refractive index mentioned later needs to be formed.

  Here, the fine particles used in the high refractive index layer include titanium oxide, zinc oxide, cerium oxide, zirconium oxide, indium-containing tin oxide, antimony-containing tin oxide and zinc antimonate from the viewpoint of film strength and refractive index after curing. The fine particles must be composed of at least one compound selected from the group, and antimony-containing tin oxide or zirconium oxide is particularly preferable from the viewpoint of high strength and dispersibility. These fine particles may be used alone or in combination of two or more.

  Such fine particles may be in the form of a powder or a solvent-dispersed sol. In the case of a solvent dispersion sol, the dispersion solvent is preferably an organic solvent from the viewpoint of compatibility with other components. Examples of such organic solvents include alcohols such as methanol, ethanol, isopropanol, and butanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, propylene glycol mono Examples thereof include esters such as ethyl ether acetate; ethers such as propylene glycol monomethyl ether and ethylene glycol monomethyl ether; aromatic hydrocarbons such as benzene, toluene and xylene. Of these, methanol, isopropanol, butanol, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, toluene and xylene are preferred.

  The average primary particle size of such fine particles is preferably 2 to 2000 nm, more preferably 3 to 200 nm, and most preferably 5 to 20 nm. When the average primary particle size exceeds 2000 nm, it becomes difficult to form a highly transparent high refractive index layer. Conversely, when the average primary particle size is less than 2 nm, the strength of the particles themselves is reduced. Scratch resistance of the resulting antireflection film tends to decrease. In order to improve the dispersibility of the fine particles, various surfactants and amines may be used in combination.

  Examples of the fine particles preferably used include the following fine particle-dispersed sols that are commercially available. Zirconium oxide: HXU-110JC (manufactured by Sumitomo Osaka Cement Co., Ltd.), Titanium oxide: Nanotech Ti-Tolu (Ci Kasei), Zinc oxide: Nanotech ZnO-Xylene (Ci Kasei), Cerium oxide: Nidral (Taki Chemical) Indium-containing tin oxide: products manufactured by Mitsubishi Materials, antimony-containing tin oxide: SN-100D (manufactured by Ishihara Sangyo Co., Ltd.), zinc antimonate: Cellnax series (manufactured by Nissan Chemical Industries, Ltd.), and the like.

  The fine particles have a polymerizable surface from the viewpoint of improving the dispersibility and from the viewpoint of improving the film strength by generating crosslinking points with a binder matrix (obtained by curing polyfunctional (meth) acrylate). It is preferable to perform the treatment with a treating agent. Examples of the surface treatment agent preferably used include a substance containing a silanol group or generating a silanol group by hydrolysis (hereinafter referred to as a silane coupling agent). Furthermore, a silane coupling agent having a polymerizable functional group other than a silanol group is preferable. The silanol groups of these substances and the hydroxyl groups on the surface of the fine particles can be reacted by heat or the like, and a silane coupling agent is bonded to the surface of the particles to form a state in which they are easily dispersed in an organic component. Examples of polymerizable functional groups other than silanol groups include acryloyl group, methacryloyl group, vinyl group, propenyl group, butadienyl group, styryl group, ethynyl group, acrylamide group, hydroxyl group, glycidyl group and the like.

  Examples of such a substance having a polymerizable functional group in addition to the silanol group include TSL-8350, TSL-8337, TSL-8370, TSL-8375 (manufactured by GE Toshiba Silicone), A-187 (Nippon Unica). -Made).

  When performing the surface treatment of the fine particles, first, the silane coupling agent as described above and the fine particles to be treated (dispersed sol) are mixed, and after adding ion-exchanged water, the silane coupling is performed by allowing to stand at room temperature. Advance the hydrolysis of the agent. The time required for hydrolysis varies depending on the substance used, but is usually about 1 to 24 hours. By heating to a temperature of 20 to 150 ° C. after the hydrolysis of the silane coupling agent has sufficiently progressed, fine particles in which the silanol groups of the silane coupling agent have reacted with the hydroxyl groups on the particle surface can be obtained.

  Next, the polyfunctional (meth) acrylate compound contained in the curable resin for forming the high refractive index layer is a compound having a plurality of (meth) acryloyl groups in the molecule, and is subjected to a photocrosslinking reaction. Thus, a coating film having sufficient strength can be formed. The compounds preferably used include neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolethane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, Dipentaerythritol tetra (meth) acrylate, alkyl-modified dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexaacrylate, alkyl-modified dipentaerythritol penta (meth) acrylate, caprolactone-modified dipenta Erythritol hexa (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate), melamine ( Can be mentioned data) acrylate, these be used alone, it may be used in combination of two or more.

  Examples of commercially available compounds containing a plurality of (meth) acryloyl groups in the molecule include Aronix M-400, M-450, M-305, M-309, M-310, M-315, and M-320. TO-1200, TO-1231, TO-595, TO-756 (above, manufactured by Toagosei Co., Ltd.), KAYARD D-310, D-330, DPHA, DPHA-2C (above, manufactured by Nippon Kayaku Co., Ltd.), SETACURE 591 (Akzo) AKCHEN GEZEL shaft), NIKARAX MX-302 (manufactured by Sanwa Chemical Co., Ltd.) and the like.

  Such a compound containing a plurality of (meth) acryloyl groups in the molecule may have a polymerizable functional group other than the (meth) acryloyl group as necessary.

  The curable resin containing the above-mentioned polyfunctional (meth) acrylate compound and fine particles as constituent components has a fine particle content of 5 to 90% by weight, preferably 30 to 85% by weight, based on the weight of the high refractive index layer. In particular, the range of 40 to 80% by weight is preferable. When the addition amount of the fine particles is less than 5% by weight, not only the refractive index of the high refractive index layer becomes insufficient and the reflection characteristics deteriorate, but also the surface of the high refractive index layer becomes smooth and the surface roughness described later. Is difficult to achieve. On the other hand, when it exceeds 90% by weight, the coating film strength after the curing treatment is reduced and the scratch resistance is lowered. In addition, when the ratio of the polyfunctional (meth) acrylate compound is less than 10% by weight, the coating film strength after the curing treatment is reduced and the scratch resistance is lowered, and conversely when it exceeds 95% by weight. Cannot contain a sufficient amount of fine particles. The total ratio of the polyfunctional (meth) acrylate compound and the fine particles is preferably 80% by weight or more, particularly 90% by weight or more, more preferably 95% by weight or more based on the weight of the high refractive index layer.

  Moreover, in order to harden a high refractive index layer by photocrosslinking reaction, it is preferable to add a photoinitiator. The addition amount of the photopolymerization initiator is preferably 10% by weight or less based on the weight of the high refractive index layer. If the amount added exceeds 10% by weight, the photopolymerization initiator may act as a plasticizer to lower the coating strength.

  Examples of photopolymerization initiators preferably used include 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, xanthone, fluorenone, anthraquinone, benzaldehyde, fluorene, triphenylamine, carbazole, 3-methylacetophenone. 4-chlorobenzophenone, 2,2-dimethoxy-2-phenylacetophenone, 2-methyl-1,1 [4- (methylthio) phenyl] -2-morpholino-propan-1-one, 2,4,6-trimethyl Examples thereof include benzoyldiphenylphosphine oxide and bis- (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide.

  The curable resin used for forming the high refractive index layer of the present invention is obtained by crosslinking the fine particles, particularly the surface-treated fine particles, and a compound having a plurality of (meth) acryloyl groups in the molecule. For the purpose of improving the affinity with the binder matrix, it is preferable to add a hydroxyl group-containing polymer. Specific examples include polyvinyl alcohol resins, polyacrylic resins, and polyphenol resins. Of these hydroxyl group-containing polymers, polyvinyl butyral resin is particularly preferred from the viewpoints of adhesion, mechanical properties of the coating film, and dispersibility of the treated inorganic particles. Among the polyvinyl butyral resins, those having a number average molecular weight of 3000 or more, preferably 10,000 or more, a vinyl alcohol unit ratio in one molecule of 18% by weight or more, and a glass transition point of 70 ° C. or more are used. preferable.

  Examples of commercially available polyvinyl butyral resins include Denka Butyral 2000-L, 3000-1, 3000-2, 3000-4 (manufactured by Denki Kagaku Kogyo Co., Ltd.), ESREC B, ESREC K (manufactured by Sekisui Chemical Co., Ltd.), and the like. Is mentioned.

  The amount of the hydroxyl group-containing polymer added is preferably 0.01 to 20% by weight, more preferably 0.5 to 10% by weight, based on the weight of the formed high refractive index layer. When the addition amount of the hydroxyl group-containing polymer is less than 0.01% by weight, it is difficult to obtain a sufficient effect for improving the affinity between the surface-treated fine particles and the binder matrix, and the effect of improving the film strength cannot be obtained. On the other hand, when it exceeds 20% by weight, the amount of the polyvinyl butyral resin in the film becomes too large, and the film strength of the high refractive index layer is lowered.

In order to form the high refractive index layer of the present invention described above, the above-mentioned polyfunctional (meth) acrylate, (surface-treated) fine particles, hydroxyl group-containing polymer, photopolymerization initiator, etc. are dissolved or dispersed in a solvent. After coating on the hard coat layer of the substrate film on which the hard coat layer is laminated, it is dried at 50 to 100 ° C., preferably 60 ° C. to 90 ° C., and then light with an energy of 100 to 2000 mJ / m ^2. Irradiation or electron beam irradiation may be performed. The solvent to be used is not particularly limited. For example, ketones such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, alcohols such as methanol, ethanol, propanol, n-butanol, secondary butanol, t-butanol and isopropyl alcohol, butyl acetate, Esters such as ethyl acetate, toluene, xylene, aromatic hydrocarbons and the like are used. Of these, ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and acetylacetone are preferable from the viewpoint of solubility. The organic solvent is preferably used in such a ratio that the total solid concentration of the solution for forming the hard coat is 1 to 70% by weight.

The high refractive index layer thus formed has a refractive index depending on the type of polyfunctional (meth) acrylate compound, fine particles (surface-treated), hydroxyl group-containing polymer, photopolymerization initiator, etc. to be used. Is in the range of 1.55 to 1.65, particularly in the range of 1.56 to 1.64, and the surface average roughness (Ra: centerline surface roughness at an area of 0.06 mm ² ) is 2. -20 nm, preferably in the range of 3-15 nm, 10-point average surface roughness (Rz) is 15 nm or more, preferably 2-4 times the average particle diameter of the fine particles in the high refractive index layer Is required to improve the adhesion to the low refractive index layer described later and improve the scratch resistance. When the refractive index is out of the above range, the antireflection property is lowered, which is not preferable. In addition, when the surface average roughness (Ra) is less than 2 nm, or when the 10-point average surface roughness (Rz) is less than 15 nm, the adhesion with the low refractive index layer described later is lowered and scratch resistance is obtained. On the other hand, when the surface average roughness (Ra) exceeds 20 nm, the haze of the obtained antireflection film may be increased, which is not preferable. In order to realize such surface roughness of the high refractive index layer, the average particle diameter of the fine particles to be added and the amount of the fine particles to be added may be adjusted.

  In addition, if the film thickness of the high refractive index layer of the present invention is too thin, it may not only be difficult to apply uniformly, but the coating strength may decrease. Since it becomes difficult and the reflectivity may be lowered, it is appropriate that the thickness is in the range of 30 to 160 nm, preferably 50 to 140 nm, particularly preferably 70 to 120 nm. The high refractive index layer contains a photosensitizer, a leveling agent, a plasticizer, an ultraviolet absorber, an antioxidant, an antistatic agent, a pigment, a dye and the like within a range not impairing the object of the present invention. It doesn't matter.

  The antireflection film of the present invention contains a polysiloxane segment in the high refractive index layer, has a fluorine content of 30% by weight or more, preferably 40 to 60% by weight, and a number average molecular weight in terms of polystyrene of 5000 or more. Preferably, a low refractive index layer made of a curable resin containing a fluorine-containing polyolefin polymer and a crosslinking agent component, preferably in the range of 7000 to 100,000, must be formed. Here, when the content of the fluorine element is less than 30% by weight, the performance as an antireflection film becomes insufficient. In addition, the antireflection effect improves as the fluorine content increases. However, if the content exceeds 60% by weight, the solubility / dispersibility of the fluorine-containing polyolefin polymer in the solvent generally decreases, and it is used in combination. The compatibility with the crosslinking agent component is also lowered, and the haze of the resulting antireflection film tends to increase. Also, the coating strength tends to be low.

  The proportion of the fluorine-containing polyolefin polymer and the crosslinking agent component is suitably in the range of 30 to 70% by weight, particularly 40 to 60% by weight, based on the total weight of both. When the proportion of the polyolefin is less than 30% by weight, it is difficult to lower the refractive index of the obtained antireflection layer, and the antireflection effect tends to be reduced. The amount of the agent component is insufficient, and the scratch resistance tends to be lowered.

  Further, the ratio of the polysiloxane segment in the fluorine-containing polyolefin polymer is such that the ratio as the siloxane unit is 0.1 to 20 mol%, preferably based on the total number of moles of the olefinic repeating unit and the siloxane repeating unit. Is suitably in the range of 0.2 to 15 mol%, most preferably 0.3 to 10 mol%. When the ratio of the siloxane segment is out of the above range, the transparency of the low refractive index layer is lowered, which is not preferable. In addition, when this ratio is 0.1 mol% or more, when the inorganic fine particles are added to the low refractive index layer, the effect that the dispersibility is improved is also expressed.

  Further, when the number average molecular weight in terms of polystyrene of the fluorinated polyolefin polymer is less than 5,000, it is difficult to control the molecular weight during polymerization, and the polymer has a large molecular weight distribution. In this case, the reproducibility of properties such as antifouling property and strength of the obtained coating film is insufficient, which is not preferable.

  The fluorine-containing polyolefin-based polymer used here is, for example, a monomer having a polysiloxane compound containing an azo group in the main chain as a radical generator and having simultaneously polymerizable double bonds and fluorine atoms in the molecule. Is a polymer obtained by using singly or in combination of two or more. Examples of the monomer preferably used include (1) fluoroolefins such as tetrafluoroethylene, hexafluoropropylene, and 3,3,3-trifluoropropylene; (2) alkyl perfluorovinyl ethers or alkoxyalkyl perfluorovinyl ethers; (3) Perfluoro (alkyl vinyl ethers) such as perfluoro (methyl vinyl ether), perfluoro (ethyl vinyl ether), perfluoro (propyl vinyl ether), perfluoro (butyl vinyl ether), perfluoro (isobutyl vinyl ether); (4) perfluoro (propoxypropyl vinyl ether) Perfluoro (alkoxyalkyl vinyl ether) such as Of these, hexafluoropropylene, perfluoroalkyl perfluorovinyl ether, and perfluoroalkoxyalkyl perfluorovinyl ether are preferable, and a combination of these is particularly preferable.

  In order to adjust the content of elemental fluorine, a non-fluorine-containing monomer having an unsaturated double bond polymerizable in the molecule may be copolymerized. Examples of preferable ones include (1) methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, tert-butyl vinyl ether, n-pentyl vinyl ether, n-hexyl vinyl ether, n -Alkyl vinyl ethers or cycloalkyl vinyl ethers such as octyl vinyl ether, n-dodecyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexyl vinyl ether; (2) vinyl acetate, vinyl propionate, vinyl butyrate, vinyl pivalate, vinyl caproate, vinyl versatate Carboxylic acid vinyl esters such as vinyl stearate; (3) methyl (meth) acrylate, ethyl (Meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2- (n-propoxy) ethyl (meth) acrylate, etc. (4) (Meth) acrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid and other unsaturated carboxylic acids.

  Such a fluorine-containing polyolefin polymer is obtained by copolymerizing a monomer having a functional group capable of reacting with a crosslinking agent component used together, for example, when a crosslinking agent component is a melamine compound, introducing a hydroxyl group into a side chain. However, it is preferable because the surface hardness of the obtained low refractive index layer can be further increased. Here, the functional group capable of reacting with the cross-linking agent component varies depending on the type of the cross-linking agent component. For example, when the cross-linking agent component is a melamine resin or an epoxy resin, a hydroxyl group or an epoxy group is preferable. You may have.

  Examples of the monomer containing a hydroxyl group include (1) 2-hydroxyethyl vinyl ether, 3-hydroxypropyl vinyl ether, 2-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether, 3-hydroxybutyl vinyl ether, 5-hydroxypentyl vinyl ether, 6 Hydroxyl group-containing vinyl ethers such as hydroxyhexyl vinyl ether; (2) hydroxyl group-containing allyl ethers such as 2-hydroxyethyl allyl ether, 4-hydroxybutyl allyl ether, glycerol monoallyl ether; (3) allyl alcohol; (4) hydroxy An ethyl (meth) acrylic acid ester etc. can be mentioned. These monomers can be used alone or in combination of two or more.

式中、Ｒ_１はメチル基またはフェニル基、Ｒ_２、Ｒ_３およびＲ_４は有機基を表し、ｘは１〜２００、ｎは１〜２０の整数を表す。 In addition, examples of the polysiloxane compound containing an azo group include compounds represented by the following chemical formula.

In the formula, R ₁ represents a methyl group or a phenyl group, R ₂ , R ₃ and R ₄ represent an organic group, x represents 1 to 200, and n represents an integer of 1 to 20.

  When using such an azo group-containing polysiloxane compound, it is preferable to introduce a segment in which the polysiloxane segment is partially linked with an azo group into the fluorine-containing polyolefin polymer by controlling the reaction conditions. . Since the azo group-containing polysiloxane segment can be a heat radical generation source, it is preferable because crosslinking is facilitated when the low refractive index layer coating film is subjected to a thermal crosslinking reaction.

  Next, when the crosslinker component used in the low refractive index layer of the present invention has a functional group capable of reacting with the crosslinker component in the fluorine-containing polyolefin polymer, such as a hydroxyl group or an epoxy group, a hydroxyl group or an epoxy group is used. Examples thereof include amino compounds having a hydroxyalkylamino group and an alkoxyalkylamino group capable of reacting with a group, and various hydroxyl group-containing compounds such as pentaerythritol, polyphenol and glycol capable of reacting with an epoxy group. Of these, amino compounds such as melamine compounds, urea compounds, benzoguanamine compounds and glycoluril compounds are preferable, and melamine compounds are particularly preferable.

  This melamine compound is a compound having a structure in which a nitrogen atom is bonded to a triazine ring. Specifically, melamine, alkylated melamine, methylol melamine, alkoxylated methyl melamine, and the like exist, but in the present invention, Those having one or both of a methylol group and an alkoxylated methyl group in total in a molecule are preferred from the viewpoint of the surface hardness of the resulting low refractive index layer. Specifically, methylolated melamine obtained by reacting melamine and formaldehyde under basic conditions, alkoxylated methylmelamine, or a derivative thereof is preferable. Particularly, both storage stability and reactivity of the curable resin are good. Of these, alkoxylated methylmelamine is preferred.

  Various methylolated melamines and alkoxylated methylmelamines that are preferably used are commercially available depending on their production methods, but there is no particular limitation in the present invention. For example, the document “Plastic Materials Course [8] Various resinous substances obtained by the method described in “Melamine Resin” (Nikkan Kogyo Shimbun) can be used.

  In addition to urea, examples of the urea compound include polymethylolated urea, alkoxylated methylurea that is a derivative thereof, methylolated uron having a uron ring, and alkoxylated methyluron. Also about this urea compound, the various resinous materials described in the said literature can be used like the said melamine compound.

  In the present invention, in order to sufficiently advance the cross-linking reaction between the cross-linking agent component and the fluorinated polyolefin polymer having a cross-linkable functional group, it is preferable to use a component having a catalytic action of the reaction in combination. Thus, for example, the heating conditions for thermosetting can be improved to be milder. As the component having such a catalytic action, when the crosslinking agent component is an amino compound such as a hydroxyalkylamino group or an alkoxyalkylamino group capable of reacting with a hydroxyl group, a thermal acid generator, for example, various aliphatic sulfonic acids and their Various aliphatic carboxylic acids and salts thereof such as salts, citric acid, acetic acid and maleic acid, various aromatic carboxylic acids and salts thereof such as benzoic acid and phthalic acid, alkylbenzene sulfonic acid and ammonium salts thereof, various metal salts and phosphoric acid And phosphoric acid esters of organic acids.

  The use ratio of such a thermal acid generator is too high, so that the storage stability of the curable resin is lowered. Therefore, 10% by weight based on the weight of the fluorinated polyolefin polymer in the curable resin. In the following, it is particularly suitable to be in the range of 0.1 to 5 wt%.

  Fine particles may be added to the low refractive index layer of the present invention for the purpose of improving the coating film strength and scratch resistance. Although there is no restriction | limiting in particular as microparticles | fine-particles to add, A silicon oxide, aluminum oxide, a silicone resin, etc. are preferable from a viewpoint of the film | membrane intensity | strength of a coating film after hardening, slipperiness, and an optical characteristic. Of these, silicon oxide is preferred from the viewpoint of coating strength. These fine particles can be used alone or in combination of two or more.

  The shape of the fine particles is not particularly limited, but is preferably in the form of powder or solvent dispersion sol. Moreover, the preferable range of the addition amount and the particle diameter is the same as that of fine particles added to the hard coat layer described later.

  The fine particles are preferably treated with a polymerizable surface treatment agent from the viewpoint of improving dispersibility and generating a crosslinking point with the fluorine-containing polyolefin polymer to improve the strength of the coating film. Examples of the surface treating agent preferably used include a substance containing a silanol group or generating a silanol group by hydrolysis (hereinafter referred to as a silane coupling agent). Furthermore, a silane coupling agent having a polymerizable functional group other than a silanol group is preferable. The silanol groups of these substances can undergo dehydration condensation reaction with the hydroxyl groups on the surface of the fine particles, and the silane coupling agent is bonded to the surface of the fine particles and is easily dispersed in the organic component. Examples of polymerizable functional groups other than silanol groups include acryloyl group, methacryloyl group, vinyl group, propenyl group, butadienyl group, styryl group, ethynyl group, acrylamide group, hydroxyl group, glycidyl group and the like. Among these, a hydroxyl group capable of reacting with a melamine compound that is preferable as a crosslinking agent component is preferable.

  Examples of such a substance having a polymerizable functional group other than a silanol group include TSL-8350, TSL-8337, TSL-8370, TSL-8375 (manufactured by GE Toshiba Silicone), A-9530 (Shin Nakamura). Chemical).

  In addition, if the film thickness of the low refractive index layer of the present invention is too thin, it may not only be difficult to apply uniformly, but the antireflection effect may be reduced. Conversely, if it is too thick, scratch resistance and antireflection are caused. Since the effect may be reduced, it is appropriate that the thickness is in the range of 30 to 170 nm, preferably 50 to 150 nm, particularly preferably 70 to 120 nm. The refractive index of the layer is 1.35 to 1.50, preferably 1.38 to 1.45. When the refractive index exceeds 1.50, the antireflection effect decreases. On the other hand, the smaller the lower limit, the better the antireflection effect. However, in practice, it is difficult to obtain an antireflection layer having a low refractive index. 35 or more, preferably 1.40 or more is practical.

  Moreover, it is preferable that the component which forms the low refractive index layer of this invention has penetrate | invaded in the range of 10-30 nm in depth in the said high refractive index layer, and thereby, scratch resistance improves more. preferable. The penetration depth can be detected by observing the cut surface with a transmission micrograph.

In order to form the low refractive index layer of the present invention described above, the above-mentioned fluorine-containing polyolefin polymer, crosslinking agent component, fine particles (surface-treated), crosslinking accelerator, etc. are dissolved or dispersed in a solvent. After coating on the above-described high refractive index layer, when the crosslinking agent component is photocrosslinkable, it is dried at 50 to 100 ° C., preferably 60 to 90 ° C., and then has an energy of 100 to 2000 mJ / m ² . In the case of a heat-crosslinkable, particularly a melamine compound, it is thermally crosslinked at 60 to 160 ° C. for 10 to 120 seconds, particularly at 120 to 160 ° C. for 20 to 60 seconds. Just do it. The solvent to be used is not particularly limited. For example, ketones such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, alcohols such as methanol, ethanol, propanol, n-butanol, secondary butanol, t-butanol and isopropyl alcohol, butyl acetate, Esters such as ethyl acetate, toluene, xylene, aromatic hydrocarbons and the like are used. Of these, ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and acetylacetone are preferable from the viewpoint of solubility. The organic solvent is preferably used in such a ratio that the total solid concentration of the solution for forming the hard coat is 1 to 70% by weight.

  Next, the hard coat layer laminated on the base film used in the reflective film of the present invention is not particularly limited as to the constituent material, and a conventionally known one may be used. As such a material, an arbitrary material such as a siloxane resin, an acrylic resin, a melamine resin, and an epoxy resin can be used, and these may be used alone or in combination of two or more. Among these, acrylate resins having photocurability, for example, acrylic resins having a plurality of (meth) acryloyl groups in the molecule, such as dipentaerythritol hexaacrylate, are preferable. In these resins, it is preferable to add fine particles composed of silicon oxide, aluminum oxide, silicone resin, etc. from the viewpoint of the strength, slipperiness, optical properties, etc. of the coating film. Among these, silicon oxide fine particles are preferable from the viewpoint of film strength. These fine particles may be used alone or in combination of two or more.

  Such fine particles are preferably in the form of a powder or a solvent-dispersed sol. In the case of a solvent-dispersed sol, the dispersion medium is preferably an organic solvent from the viewpoint of compatibility with other components. Examples of such organic solvents include alcohols such as methanol, ethanol, isopropanol, and butanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, propylene glycol mono Examples thereof include esters such as ethyl ether acetate; ethers such as propylene glycol monomethyl ether and propylene glycol monomethyl ether; aromatic hydrocarbons such as benzene, toluene and xylene. Of these, methanol, isopropanol, butanol, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, toluene and xylene are preferred.

  The average primary particle size of such inorganic fine particles is preferably 2 to 2000 nm, more preferably 3 to 200 nm, and most preferably 5 to 100 nm. When the average primary particle size exceeds 2000 nm, it becomes difficult to obtain a highly transparent coating film. Conversely, when the average primary particle size is less than 2 nm, the strength of the particles themselves is low, and the coating with high hardness is used. It is difficult to obtain a film. Various surfactants and amines may be used in combination to improve the dispersibility of the fine particles.

  Examples of the fine particles preferably used include the following fine particle-dispersed sols that are commercially available. That is, as the silicon oxide fine particles, for example, IPA-ST, MEK-ST, NBA-ST, XBA-ST, DMAC-ST, ST-UP, ST-OUP, ST-20, ST-40 (above Nissan Chemical Co., Ltd.) Examples of the aluminum oxide fine particles include alumina sol 100, alumina sol 200, alumina sol 500 (manufactured by Nissan Kagaku Co., Ltd.), AS-150I, AS-150T (manufactured by Sumitomo Osaka Cement), and the like. Examples of the silicone particles include N-31-4 (manufactured by Nippon Pure Chemicals Co., Ltd.).

  The amount of the fine particles added is preferably 5 to 90% by weight, more preferably 10 to 85% by weight, and most preferably 20 to 80% by weight, based on the hard coat layer to be formed as 100% by weight. It is a range. When the addition amount is less than 5% by weight, it is difficult to sufficiently increase the film strength and slipperiness of the hard coat layer. On the other hand, when the added amount exceeds 90% by weight, not only is it difficult to hold the particles in the hard coat layer after curing, but the optical characteristics are also likely to deteriorate.

  Such fine particles are preferably treated with a polymerizable surface treating agent from the viewpoint of improving the dispersibility and generating a cross-linking point with the binder matrix to improve the coating film strength. Examples of the surface treatment agent preferably used include a substance containing a silanol group or generating a silanol group by hydrolysis (hereinafter referred to as a silane coupling agent). Furthermore, a silane coupling agent having a polymerizable functional group other than a silanol group is preferable. The silanol group of these substances and the hydroxyl group on the surface of the fine particles described above can react by heat or the like, and a silane coupling agent is bonded to the surface of the particle, so that it can be easily dispersed in an organic component. Examples of polymerizable functional groups other than silanol groups include acryloyl group, methacryloyl group, vinyl group, propenyl group, butadienyl group, styryl group, ethynyl group, acrylamide group, hydroxyl group, glycidyl group and the like.

  Examples of such a substance having a polymerizable functional group in addition to the silanol group include TSL-8350, TSL-8337, TSL-8370, TSL-8375 (manufactured by GE Toshiba Silicone), A-187 (Nippon Unica). -Made).

  When performing the surface treatment of the fine particles, first, the silane coupling agent as described above and the inorganic particles (dispersed sol) to be treated are mixed, and after adding ion-exchanged water, the silane cup is allowed to stand at room temperature. Proceed with hydrolysis of ring agent. The time required for hydrolysis varies depending on the substance used, but is about 1 to 24 hours. By heating to a temperature of 20 ° C. to 150 ° C. after the hydrolysis of the silane coupling agent has sufficiently progressed, particles in which the silanol groups of the silane coupling agent and the hydroxyl groups on the particle surface have reacted can be obtained.

  Furthermore, a hydroxyl group-containing polymer is added to the hard coat layer containing the fine particles for the purpose of improving the affinity between the fine particles and a binder matrix obtained by crosslinking polyfunctional (meth) acrylate. Is preferred. Specific examples include polyvinyl alcohol resins, polyacrylic resins, and polyphenol resins. Of these hydroxyl group-containing polymers, polyvinyl butyral resin is particularly preferred from the viewpoints of adhesion to the substrate, mechanical properties of the coating film, and dispersibility of the treated inorganic particles. Among the polyvinyl butyral resins, the number average molecular weight is 3000 or more, preferably 10,000 or more, the ratio of vinyl alcohol units in one molecule is 18% by weight or more, and the glass transition point is 70 ° C. or more. Is preferred. Furthermore, polyvinyl butyral having two or more (meth) acryloyl groups in its side chain is preferable because the coating film strength is further improved.

  Examples of commercially available products of polyvinyl butyral resin include Denka Butyral 2000-L, 3000-1, 3000-2, 3000-4 (more than electrochemical industry), ESREC B, ESREC K (more than Sekisui Chemical). Can be mentioned.

  The amount of the hydroxyl group-containing polymer added is preferably 0.01 to 20% by weight, more preferably 0.5 to 10% by weight, with the hard coat layer formed being 100% by weight. When the addition amount of the hydroxyl group-containing polymer is less than 0.01% by weight, it is difficult to obtain a sufficient effect for improving the affinity between the surface-treated fine particles and the binder matrix, and the effect of improving the film strength cannot be obtained. Moreover, when 20 weight% or more is added, the quantity of the polyvinyl butyral resin which occupies in a film | membrane will increase too much, and the surface hardness of a coating film will also fall in this case.

  Next, an acrylate resin (polyfunctional (meth) acrylate compound) having a plurality of (meth) acryloyl groups in the molecule preferably used in the hard coat layer is subjected to a photocrosslinking reaction to form a coating film having sufficient strength. Can be formed. Polyfunctional (meth) acrylates preferably used include neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate in addition to the dipentaerythritol hexaacrylate mentioned above. , Trimethylolethane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, alkyl-modified dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, alkyl-modified di Pentaerythritol penta (meth) acrylate, caprolactone-modified dipentaerythritol hexa (meth) acrylate, ditrimethylolpropante La (meth) acrylate), melamine (meth) acrylate can be exemplified, and these may be used alone, may be used in combination of two or more.

  Examples of commercially available compounds containing a plurality of (meth) acryloyl groups in the molecule include Aronix M-400, M-450, M-305, M-309, M-310, M-315, and M-320. TO-1200, TO-1231, TO-595, TO-756 (above, manufactured by Toagosei Co., Ltd.), KAYARD D-310, D-330, DPHA, DPHA-2C (above, manufactured by Nippon Kayaku Co., Ltd.), SETACURE 591 (Akzo) AKCHEN GEZEL shaft), NIKARAX MX-302 (manufactured by Sanwa Chemical Co., Ltd.) and the like.

  A compound having a polymerizable functional group other than the (meth) acryloyl group may be used in combination with the compound containing a plurality of (meth) acryloyl groups in the molecule. Moreover, you may give polymerizable functional groups other than a (meth) acryloyl group with several (meth) acryloyl group in a molecule | numerator.

  It is preferable to add a photopolymerization initiator for photocrosslinking reaction / curing of the hard coat layer. The addition amount of the photopolymerization initiator is preferably 10% by weight or less based on the weight of the hard coat layer. When the addition amount exceeds 10% by weight, the photopolymerization initiator may act as a plasticizer to lower the film strength.

In order to form the hard coat layer of the present invention described above, the above-mentioned polyfunctional (meth) acrylate, (surface-treated) fine particles, a hydroxyl group-containing polymer, a photopolymerization initiator, etc. are dissolved in a solvent or After being dispersed and applied to the substrate film, it is dried at 50 to 100 ° C., preferably 60 to 90 ° C., and then irradiated with light or electron beam with an energy of 100 to 2000 mJ / m ² . The solvent to be used is not particularly limited. For example, ketones such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, alcohols such as methanol, ethanol, propanol, n-butanol, secondary butanol, t-butanol and isopropyl alcohol, butyl acetate, Esters such as ethyl acetate, toluene, xylene, aromatic hydrocarbons and the like are used. Of these, ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and acetylacetone are preferable from the viewpoint of solubility. The organic solvent is preferably used in such a ratio that the total solid concentration of the solution for forming the hard coat is 1 to 70% by weight.

  The hard coat layer may contain a photosensitizer, a leveling agent, a plasticizer, an ultraviolet absorber, an antioxidant, an antistatic agent, a pigment, a dye, or the like within a range not impairing the object of the present invention. I do not care.

  The refractive index of the hard coat layer is not particularly limited because the layer itself does not directly affect the antireflection performance, but is 1.45 to 1.55 from the viewpoint of easy visibility of interference spots and coating spots. Is preferable, and the range of 1.47 to 1.52 is more preferable.

  Next, the base film in the present invention is not particularly limited, but (meth) acrylic resin, polystyrene, polyvinyl acetate, polyolefin such as polyethylene and polypropylene, polyvinyl chloride, polyvinylidene chloride, polyimide, polyamide Polysulfone, Polycarbonate, Polyethylene terephthalate (hereinafter sometimes referred to as PET), Polyester such as polyethylene naphthalate (hereinafter sometimes referred to as PEN) (20 mol% or less based on the total acid component, preferably 10% by mole or less of the third component may be copolymerized), a resin partially modified with a functional group such as an amino group, an epoxy group, a hydroxyl group, or a carbonyl group, a film made of triacetyl cellulose (TAC), etc. Is preferred.

  Among these base films, polyester films, particularly PET films and PEN films are preferable from the viewpoint of mechanical properties and transparency. At that time, the thickness of the base film is not particularly limited and may be set as appropriate according to the application. When it exceeds 500 μm, the rigidity of the antireflection film becomes too strong, and the handleability when pasting on the display is lowered.

  In addition, when applying the above-mentioned coating liquid to, for example, a polyester film, if necessary, as a pretreatment for improving adhesion and coating properties, the polyester film surface may be subjected to corona discharge treatment, plasma discharge treatment, or the like. Applying a physical surface treatment or applying a chemical surface treatment to form a coating film adhesion layer (anchor coat layer) by applying an organic resin-based or inorganic resin-based paint during or after film formation preferable. When the anchor coat layer is formed, the refractive index and the film thickness of the anchor coat layer are carefully set from the viewpoint of light interference conditions with the hard coat layer and the like applied thereon.

  Examples of the anchor coat layer resin that is preferably used include transparent polymer binders such as polyurethane, polyacrylate, polyester, polyvinyl pyrrolidone, polyvinyl alcohol, and polyvinyl alcohol / polyethylene copolymer. Among these, from the viewpoint of adhesiveness, a polymer binder containing both a polyester resin and an acrylic resin having an oxazoline group and a polyalkylene oxide chain as constituent components is preferable.

  Examples of the polyester resin used herein include polyesters composed of the following polybasic acids and polyols, but are particularly soluble or dispersible in water (may contain some organic solvent). Polyester is preferred. The acrylic resin having an oxazoline group and a polyalkylene oxide chain is also preferably an acrylic resin that is soluble or dispersible in water (may contain some organic solvent).

  Such an acrylic resin having an oxazoline group and a polyalkyleneoxy chain contains, for example, a monomer having the following oxazoline group and a monomer having a polyalkylene oxide chain as copolymerization components, and includes other copolymerization components. It does not matter.

  First, examples of the monomer having an oxazoline group include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline. 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-methyl-2-oxazoline, and the like, and one or a mixture of two or more thereof can be used. Of these, 2-isopropenyl-2-oxazoline is preferred because it is easily available industrially. By using such an acrylic resin having an oxazoline group, the cohesive force of the anchor coat layer is improved, and the adhesion to the hard coat layer is further strengthened. Furthermore, the abrasion resistance with respect to the metal roll in a film forming process and a coating-film processing process can be provided to the base film surface. In addition, content of the monomer containing an oxazoline group is 2 to 40 weight% as content in this acrylic resin, Preferably it is 3 to 35 weight%, More preferably, it is 5 to 30 weight%.

  Next, examples of the monomer having a polyalkylene oxide chain include those obtained by adding polyalkylene oxide to an ester part of acrylic acid or methacrylic acid. Examples of the polyalkylene oxide chain include polymethylene oxide, polyethylene oxide, polypropylene oxide, and polybutylene oxide. The repeating unit of the polyalkylene oxide chain is preferably 3 to 100. By using such an acrylic resin having a polyalkylene oxide chain, the compatibility between the polyester resin and the acrylic resin in the anchor coat layer is better than that of an acrylic resin not containing a polyalkylene oxide chain, and the transparency of the anchor coat layer is improved. Can be improved. Here, when the repeating unit of the polyalkylene oxide chain is smaller than 3, the compatibility between the polyester resin and the acrylic resin is lowered and the transparency of the anchor coat layer is deteriorated. Decrease, adhesion at high humidity and high temperature deteriorates. In addition, content of the monomer which has a polyalkylene oxide chain is 3 to 40 weight% as content in this acrylic resin, Preferably it is 4 to 35 weight%, More preferably, it is 5 to 30 weight%.

  The content ratio of the polyester resin forming the anchor coat layer in the anchor coat layer is preferably 5 to 95% by weight, and particularly preferably 50 to 90% by weight. The content of the acrylic resin having an oxazoline group and a polyalkylene oxide chain forming the anchor coat layer in the anchor coat layer is preferably 5 to 90% by weight, and particularly preferably 10 to 50% by weight. If the polyester resin exceeds 95% by weight, or the acrylic resin having an oxazoline group and a polyalkylene oxide chain is less than 5% by weight, the cohesive force of the anchor coat layer may be lowered and adhesion may be insufficient.

  The anchor coat layer preferably contains 0.5 to 30% by weight of aliphatic wax, particularly preferably 1 to 10% by weight. When this ratio is less than 0.5% by weight, the effect of improving the smoothness of the film surface may not be recognized. On the other hand, if it exceeds 30% by weight, the adhesion to the substrate film and the anchor coat property to the hard coat layer or the antireflection layer may be insufficient.

  Furthermore, the anchor coat layer preferably contains 0.1 to 20% by weight of particles having an average particle size in the range of 0.005 to 0.5 μm. When the content of the particles in the anchor coat layer is less than 0.1% by weight, the slipperiness of the film may be lowered and it may be difficult to wind the film into a roll. Conversely, if it exceeds 20% by weight, the transparency of the anchor coat layer may be lowered. The difference in refractive index between the polymer binder forming the anchor coat layer and the fine particles is preferably 0.02 or less from the viewpoint of the antireflection effect and haze, and can be obtained when the refractive index difference exceeds this value. The transparency of the antireflection film may be reduced.

  Next, in order to form the anchor coat layer on the base film, the above components are preferably used in the form of an aqueous coating solution such as an aqueous solution, an aqueous dispersion or an emulsion. In order to form a coating film, in addition to the above components, other components such as an antistatic agent, a colorant, a surfactant, and an ultraviolet absorber can be added as necessary. In particular, the addition of a lubricant can further improve the blocking resistance.

  The solid content concentration of the aqueous coating liquid used for coating the anchor coat layer is usually 20% by weight or less, but preferably 1 to 10% by weight. If this ratio is less than 1% by weight, the wettability to the substrate film may be insufficient, while if it exceeds 20% by weight, the storage stability of the coating liquid and the appearance of the anchor coat layer may be deteriorated. .

  The anchor coat layer can be applied to the base film at any stage. However, when the polyester film is described as an example, it is preferably performed during the production process, and the oriented crystallization is completed. It is preferably applied to the previous polyester film.

  Here, the polyester film before completion of oriented crystallization is an unstretched film, a uniaxially oriented film in which the unstretched film is oriented in either the longitudinal direction or the transverse direction, and further in two directions, the longitudinal direction and the transverse direction. And the like that have been stretched and oriented at a low magnification (biaxially stretched film before being finally re-stretched in the machine direction or transverse direction to complete orientation crystallization). In particular, it is preferable to apply an aqueous coating liquid for forming an anchor coat layer to an unstretched film or a uniaxially stretched film oriented in one direction, and to perform longitudinal stretching and / or lateral stretching and heat setting as it is.

  When applying the aqueous coating liquid for forming the anchor coat layer to the base film, physical treatment such as corona treatment, flame treatment, plasma treatment, etc. is applied to the film surface as a preliminary treatment for improving the coatability. Alternatively, it is preferable to use a chemically inert surfactant together with the composition.

  As a coating method for forming the anchor coat layer, a method known per se may be employed. For example, lip direct method, comma coater method, slit reverse method, die coater method, gravure roll coater method, blade coater method, spray coater method, air knife coat method, dip coat method, bar coater method, etc. These methods can be used alone or in combination. In addition, a coating film may be formed only in the single side | surface of a film as needed, and may be formed in both surfaces.

  Hereinafter, the present invention will be described more specifically with reference to examples. In addition, each evaluation in an Example followed the following method.

(Average particle size)
The particle diameter was measured using a light scattering method. That is, the “equivalent sphere diameter” of a particle at a point of 50% by weight of the total particle determined by NICOM MODEL 270 SUBMICRON PARTICLE SIZER manufactured by Nicomp Instruments Inc. is displayed.

(Center surface average roughness, 10-point average roughness)
Measured using a non-contact type three-dimensional surface roughness meter (manufactured by ZYGO: New View 5022) at a measurement magnification of 10 times and a measurement area of 283 μm × 213 μm (= 0.06 mm ² ), and incorporated in the roughness meter The center surface average roughness (Ra) and 10-point average roughness (Rz) are obtained by the surface analysis software Metro Pro.

(Reflectance)
The reflectance at a wavelength of 300 to 800 nm on the antireflection layer side of the sample antireflection film was measured using a reflection spectral film thickness meter (trade name “FE-3000” manufactured by Otsuka Electronics Co., Ltd.). The lowest reflectance in this region was defined as the minimum reflectance (%). It is good if the minimum reflectance is 2.0% or less.

(Film thickness, refractive index)
The film thickness and refractive index of the low refractive index layer, the high refractive index layer, and the hard coat layer are the nk Cauchy dispersion formulas as approximate expressions for the chromatic dispersion of the typical refractive index for the reflectance measurement values of the respective layers. Was obtained by fitting with the measured value of the spectrum.

(Abrasion resistance)
The surface of the obtained antireflection film was visually observed after rubbing 10 strokes of a 25 mm stroke length at a speed of 30 mm / sec by applying a load of 200 g / cm ² to # 0000 steel wool, Judgment was made according to the following criteria. 4 or more is good.
5: No more than 5 scratches 4: More than 5 scratches and no more than 10 3: No more than 10 scratches and no more than 20 2: There are 20 or more scratches and the antireflection layer is peeled off on the surface 1 : The low refractive index layer is completely peeled off in the evaluation area

(Haze)
It measured using Nippon Denshoku NDH-2000.

(Section observation)
The obtained antireflection film is frozen and cut, and the cross section is observed using a transmission electron microscope (H-9500, manufactured by Hitachi High-Technology). The low refractive index layer component penetrates into the high refractive index layer surface area. Measured depth. In the measurement, the film thickness of the intermediate region was measured at 100 nm intervals in the range of 1 μm in the in-film direction, and the average of 10 measured values was adopted.

[Example 1]
<Adjustment of paint for hard coat layer>
-Formation of surface-treated silica sol 100 parts by weight of AEROSIL 130 (silica fine particles) manufactured by Nippon Aerosil Co., Ltd., 5 parts by weight of TSL-8375 as a methacryloyl group-containing silane coupling agent, and 295 parts by weight of ion-exchanged water are mixed for 12 hours. Left to stand. Then, after volatilizing water with an evaporator, 150 parts by weight of toluene was added and reacted at 80 ° C. for 6 hours to obtain silica toluene sol.

-Preparation of coating liquid 28 parts by weight of dipentaerythritol hexaacrylate, 80 parts by weight of the above surface-treated silica toluene sol (number average particle size 0.01 μm, silica concentration 40% by weight), polyvinyl butyral as a hydroxyl group-containing polymer; 1 part by weight of Denkabutyral 2000-3 (number average molecular weight 10,000, polyvinyl alcohol unit 19 mol%, glass transition point 73 ° C.) manufactured by Industrial Co., Ltd., 2-methyl-1- [4- (methylthio) phenyl] as a photopolymerization initiator 2 parts by weight of 2-morpholinopropan-1-one (Irgacure 907, manufactured by Ciba Specialty Chemicals), methyl ethyl ketone (MEK) as a solvent was added to adjust the solid content to 40% by weight, and the mixture was stirred at 23 ° C. for 1 hour. Thus, a uniform paint for forming a hard coat layer was obtained.

<Adjustment of paint for forming high refractive index layer>
-Preparation of surface-treated spherical antimony-containing tin oxide sol 40 parts by weight of spherical antimony-containing tin oxide (SN-100P manufactured by Ishihara Techno Co., Ltd., average primary particle size 0.01 µm, hereinafter sometimes abbreviated as ATO), methacryloyl group-containing silane coupling As an agent, 5 parts by weight of TSL-8375 and 150 parts by weight of ion-exchanged water were mixed and allowed to stand for 20 hours. Then, after volatilizing water with an evaporator, 150 parts by weight of toluene was added and reacted at 80 ° C. for 6 hours to obtain a surface-treated ATO particle toluene sol.

-Preparation of coating liquid 28 parts by weight of dipentaerythritol hexaacrylate, 120 parts by weight of the above-mentioned surface-treated ATO particle toluene sol (number average particle diameter 0.01 μm, ATO concentration 40% by weight), polyvinyl butyral as a hydroxyl group-containing polymer; 10 parts by weight of Industrial Denkabutyral 2000-3 (number average molecular weight 10,000, polyvinyl alcohol unit 19 mol%, glass transition point 73 ° C.), 2-methyl-1- [4- (methylthio) phenyl] as a photopolymerization initiator 4-Morpholinopropan-1-one (Irgacure 907, manufactured by Ciba Specialty Chemicals) was adjusted to a solid content of 40 wt% by adding MEK as a solvent, and stirred at 23 ° C for 1 hour to be uniform. A coating material for forming a high refractive index layer was obtained.

<Adjustment of paint for forming low refractive index layer>
-Preparation of fluorine-containing polyolefin polymer After sufficiently replacing a stainless steel autoclave with nitrogen gas, 500 g of ethyl acetate, 50 g of perfluoropropyl vinyl ether, 50.0 g of ethyl vinyl ether and 25.0 g of hydroxybutyl vinyl ether, nonionic reaction 20.0 g of “Adekaria soap NE-30” (manufactured by Asahi Denka Kogyo Co., Ltd.) as a hydrophilic emulsifier, 5.0 g of azo group-containing polydimethylsiloxane “VPS-1001” (Wako Pure Chemical Industries, Ltd.) and polymerization initiator peroxidation After charging 1.0 g of lauroyl and cooling to −50 ° C., oxygen in the system was removed with nitrogen gas. Thereafter, 120 g of hexabath Onomichi propylene was charged, the temperature was raised, the reaction was carried out at 60 ° C. (pressure 6 kgf / cm ^{2 at} this time) for 20 hours, and when the pressure dropped to 2.5 kgf / cm ^2, the reaction was stopped by cooling with water. I let you. A polymer was precipitated from the resulting solution with methanol, and a fluorine-containing polyolefin polymer was obtained by vacuum drying.

-Preparation of coating liquid 1620 g of MEK as a solvent, 100 g of the above-mentioned fluorine-containing polyolefin polymer, 30 g of methylated melamine “Cymel 303” (manufactured by Mitsui Cytec Co., Ltd.) as a thermosetting crosslinking component, thermal acid catalyst 3 g of p-toluenesulfonic acid was charged into a glass separable flask equipped with a stirrer and stirred at a temperature of 23 ° C. for 1 hour to obtain a uniform curable resin solution. The solid content concentration was adjusted to 10% by weight with MEK.

The fluorine content of the fluorine-containing polyolefin polymer used was measured by the alizarin complexone method, and the fluorine content was 45% by weight.
The inorganic silica weight was measured from the remaining weight after firing at 600 ° C., and the molar concentration of the siloxane unit derived from the azo group-containing polydimethylsiloxane was determined from the chemical structure and found to be 3.0%.

<Creation of antireflection film>
A PET film (trade name: O3PF8W-100, manufactured by Teijin DuPont Films) is used as the base film, and the hard coat layer forming paint is applied onto the base film with a Meyer bar, and the solvent is dried at a temperature of 80 ° C. Then, a total of 800 mJ / cm ^{2 of} ultraviolet rays was irradiated with a low-pressure mercury lamp (output 80 W / cm ² ) manufactured by USHIO ELECTRIC CO., LTD. To form a hard coat layer having a thickness of 5 μm. The obtained hard coat layer had a refractive index of 1.51.

On this hard coat layer, the high refractive index layer-forming coating material prepared as described above as a high refractive index layer is applied with a Meyer bar so that the thickness after drying becomes 100 nm, and dried at 70 ° C. for 2 minutes. Subsequently, ultraviolet rays were irradiated with a low-pressure mercury lamp (output: 80 W / cm ² ) manufactured by Ushio Electric Co., Ltd. to obtain a total refractive index layer of 500 mJ / cm ² . The refractive index of the obtained high refractive index layer was 1.63. It shows in Table 1 about the surface roughness of the obtained coating film.

  On the high refractive index layer, the low refractive index layer-forming coating material prepared as described above was applied with a Meyer bar so that the thickness after drying / curing was 100 nm, and a thermosetting treatment was performed at 150 ° C. for 2 minutes. A low refractive index layer was formed. Table 1 shows the properties of the antireflection film thus obtained. The penetration depth of the low refractive index layer component into the high refractive index layer was 18 nm.

[Example 2]
In Example 1, an antireflection film was prepared in the same manner as in Example 1 except that the amount of surface-treated ATO particle toluene sol added to the coating material for forming a high refractive index layer was 150 parts by weight.

[Example 3]
In Example 1, except that zirconium oxide: HXU-110JC (primary particle size 0.01 μm, manufactured by Sumitomo Osaka Cement Co., Ltd.) was used instead of antimony-containing tin oxide used in the preparation of the coating material for forming a high refractive index layer. An antireflection film was prepared in the same manner as in Example 1.

[Comparative Example 1]
In Example 1, an antireflection film was prepared in the same manner as in Example 1 except that the amount of surface-treated ATO particle toluene sol added to the coating material for forming a high refractive index layer was 30 parts by weight.

[Comparative Example 2]
In Example 1, an antireflection film was prepared in the same manner as in Example 1 except that the amount of surface-treated ATO particle toluene sol added to the coating material for forming a high refractive index layer was 300 parts by weight.

[Comparative Example 3]
<Adjustment of paint for forming high refractive index layer>
Tetrabutyl titanate tetramer (Nihon Soda TBT B-4) in a ligroin / n-butanol (3/1) solution (adjusted to a solid concentration of 20% by weight) with silicon dioxide particles (AEROSIL R972 manufactured by Nippon Aerosil Co., Ltd.) 0.5% by weight of tetrabutyl titanate was added and dispersed.
An antireflection film was prepared in the same manner as in Example 1 except that the high refractive index layer was formed using the coating liquid described above.

[Comparative Example 4]
<Adjustment of paint for forming low refractive index layer>
Tetraethoxysilane (manufactured by High-Purity Chemical) was adjusted to a solid concentration of 15% by weight with a solvent of ethanol / water = 2/1 and allowed to stand for 12 hours to hydrolyze silicon dioxide sol (low refractive index layer formation) Paint). An antireflection film was prepared in the same manner as in Example 1 except that a low refractive index layer was formed using this paint.
Table 1 shows the properties of the antireflection films obtained in the above Examples and Comparative Examples.

  The antireflection film of the present invention described above has excellent scratch resistance because of good adhesion between the high refractive index layer and the low refractive index layer, and also has good antireflection characteristics. It can be suitably used as an antireflection film on the surface of organic EL displays, plasma displays and the like.

It is sectional drawing which shows an example of the antireflection film of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base film 2 Anchor coat layer 3 Hard coat layer 4 High refractive index layer 5 Low refractive index layer

Claims (7)

  A polyfunctional (meth) acrylate compound, titanium oxide, zinc oxide, cerium oxide, zirconium oxide, indium-containing tin oxide, antimony-containing tin oxide on a hard coat layer of a base film in which a hard coat layer is laminated on at least one side And a curable resin containing fine particles made of at least one compound selected from the group of zinc antimonate as a constituent component, and an average surface roughness (Ra) of 2 to 20 nm and an average surface roughness (Rz) of 10 points. A high refractive index layer having a refractive index of 1.55 to 1.65 having a refractive index of 1.55 to 1.65 is formed, and then has a polysiloxane segment in the main chain on the high refractive index layer, and the fluorine content is 30 A fluorine-containing polyolefin polymer having a weight average molecular weight of 5,000 or more and a cross-linking agent component in terms of polystyrene And a cured resin containing it, antireflection film by forming a low refractive index layer with a refractive index 1.35 to 1.50.   2. The antireflection film according to claim 1, wherein the fine particles in the high refractive index layer are fine particles made of antimony-containing tin oxide or zirconium oxide and have an average particle diameter of 5 to 20 nm.   The antireflection film according to claim 1 or 2, wherein the low refractive index layer component penetrates 10 to 30 nm in the high refractive index layer at the interface between the high refractive index layer and the low refractive index layer.   The antireflection film according to any one of claims 1 to 3, wherein the cross-linking agent component of the low refractive index layer is a melamine compound and is thermoset at a temperature of 120 to 160 ° C.   A curable resin in which a hard coat layer laminated on a base film contains polyfunctional (meth) acrylate and fine particles composed of at least one compound selected from the group of silicon oxide, aluminum oxide and silicone resin as constituent components The antireflection film according to claim 1, wherein the antireflection film is formed from.   The antireflection film according to claim 5, further comprising polyvinyl butyral in the curable resin forming the hard coat layer.   The antireflection film according to claim 6, wherein at least a part of polyvinyl butyral has two or more (meth) acryloyl groups in its side chain.

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