JP2012078466A - Antireflection film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antireflection film that is excellent in scratch resistance, and in which color unevenness is suppressed in a high level, and cissing of the antireflection layer does not occur, by optimizing a surface state of a hard coat layer arranged at lower most layer in the antireflection layer.SOLUTION: The film is formed by sequentially laminating the hard coat layer and the antireflection layer on at least one face of a transparent substrate in this order. The hard coat layer is formed by applying a coating liquid containing an ionizing radiation-curable material to the transparent substrate and curing it with radiation of ionizing radiation. The antireflection layer is formed by applying a coating liquid containing an ionizing radiation-curable material and a surface modifying agent having both or either one of a fluorine-containing group and a silicone skelton to the hard coat layer, and curing it with radiation of ionizing radiation. A contact angle of pure water to the hard coat surface measured according to JIS R3257 (1999) is in the range of 60° or more and 90° or less.

Description

  The present invention relates to an antireflection film provided on the surface of a display such as a liquid crystal display (LCD), a CRT display, an organic EL display, a plasma display (PDP), and a surface electric field display (SED).

  Optical display devices such as LCDs, CRTs, and plasma displays are used in an environment where external light or the like is incident, regardless of whether they are used indoors or outdoors. Incident light such as external light is specularly reflected on the display surface and the like, and the reflected image thereby mixes with the display image, thereby degrading the screen display quality. For this reason, an antireflection function is often imparted to the display surface or the like, and there is a demand for higher performance of the antireflection function and to combine functions other than the antireflection function.

  Among the displays, the LCD needs to use a polarizing plate on the panel surface because of its mechanism, and the polarizing plate is generally made of polyvinyl alcohol (PVA). Since a polarizing plate (PVA) is extremely weak in strength and water resistance, a triacetyl cellulose (TAC) film is generally used as a protective film. However, since the surface of the TAC film is relatively flexible, in order to impart surface hardness, a hard coat layer generally made of a polymer of an acrylic polyfunctional compound is provided, and an antireflection multilayer film is formed thereon. The method is used. This hard coat layer has high surface hardness, gloss, transparency, and scratch resistance due to the properties of the acrylic resin.

  In general, the antireflection function can be obtained by forming an antireflection layer having a refractive index lower than those on a transparent substrate or the hard coat layer. Furthermore, in order to improve the antireflection performance, a multilayer structure having a repeating structure of a high refractive index layer made of a transparent material such as a metal oxide and an antireflection layer may be formed on the transparent substrate or the hard coat layer. The antireflection layer having a multilayer structure can be formed by a dry coating method such as a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method.

  In forming an antireflection layer using the dry coating method, there is an advantage that the film thickness of each layer can be precisely controlled. However, since the film formation must be performed in a vacuum, a large facility is required, and There is a problem that productivity is low and it is not suitable for mass production. On the other hand, production of an antireflection film using a wet coating method using a coating liquid capable of increasing the area, continuous production, and cost is attracting attention as a method for forming an antireflection layer.

JP 2007-102206 A

  The antireflection film manufactured by the wet coating method has been used in large quantities due to the recent popularization and enlargement of LCD-TV, but at the same time, there is an increasing demand for higher functionality and higher quality. Among them, since the antireflection film is provided on the surface of the display, the demands for improving the scratch resistance to prevent the surface from being scratched and making the color unevenness inconspicuous are the greatest.

  Here, the color unevenness is a difference in reflected color seen on the screen, which is caused by a change in the reflection spectrum due to a minute film thickness variation of the antireflection layer. In order to improve the color unevenness, it is known to add a surface conditioner having a fluorine-containing group and a silicone skeleton to the coating liquid for forming the antireflection layer. These surface conditioners are localized on the outermost surface of the antireflection layer, uniformize the surface of the coating film in a wet state and impart slipperiness to the outermost surface of the antireflection layer, not only preventing the occurrence of color unevenness, Also effective in improving scratch resistance.

  However, the localization of the surface conditioning agent in the antireflection layer also depends on the surface state of the lower layer on which the antireflection layer is laminated, and depending on the adjustment of the surface conditioning agent contained in the antireflection layer, scratch resistance and color unevenness may occur. It could not be resolved sufficiently. In addition, depending on the surface state of the lower layer, there is a problem that repelling occurs when the antireflection layer is formed by the wet coating method.

  In the present invention, in view of the above problems, by optimizing the state of the hard coat layer surface located in the lower layer of the antireflection layer, it is excellent in scratch resistance and color unevenness is suppressed at a high level, And let it be a subject to provide the antireflection film without the repellency of an antireflection layer.

In order to solve the above-mentioned problem, the invention according to claim 1 is a film in which a hard coat layer and an antireflection layer are laminated in this order on at least one surface of a transparent substrate, and the hard coat layer is ionizing radiation. A coating liquid containing a curable material is applied on the transparent substrate and cured by irradiation with ionizing radiation, and the antireflection layer includes both an ionizing radiation curable material, a fluorine-containing group, and a silicone skeleton, or A coating liquid containing a surface conditioner having either one is applied onto the hard coat layer and cured by ionizing radiation irradiation, and the purity of the hard coat layer surface measured by JIS R3257 (1999) The antireflection film was characterized in that the water contact angle was in the range of 60 ° to 90 °.
The invention according to claim 2 is characterized in that the contact angle of pure water on the surface of the hard coat layer measured by JIS R3257 (1999) is in the range of 70 ° to 80 °. The antireflection film described in 1 was used.
The invention according to claim 3 is characterized in that the hard coat layer contains a surface conditioner having both or one of fluorine-containing groups and a silicone skeleton. Antireflection film.
Moreover, as invention of Claim 4, as for the antireflection film in any one of Claims 1 thru | or 3, a polarizing layer in order from this transparent base material side to the non-formation surface of the transparent base material of this antireflection film, It was set as the polarizing plate provided with a transparent base film.
According to a fifth aspect of the invention, in order from the observer side, the polarizing plate according to the fourth aspect, a liquid crystal cell, a second polarizing plate, and a backlight unit are provided in this order, and the antireflection is provided. A transmissive liquid crystal display characterized in that the layer is located on the outermost surface on the viewer side.
The invention according to claim 6 is a method for producing a film in which a hard coat layer and an antireflection layer are laminated in this order on at least one surface of a transparent substrate, and the coating liquid contains an ionizing radiation curable material. A surface adjusting agent having a step of forming a hard coat layer by applying it onto the transparent substrate and curing by irradiation with ionizing radiation, and an ionizing radiation curable material, a fluorine-containing group, and / or a silicone skeleton. And a step of applying a coating liquid onto the hard coat layer and curing it by irradiation with ionizing radiation to form an antireflection layer, and measuring the hardness measured by JIS R3257 (1999) before forming the antireflection layer. The method for producing an antireflection film is characterized in that the contact angle of pure water on the surface of the coating layer is in the range of 60 ° to 90 °.

  In the present invention, by optimizing the surface state of the hard coat layer, the anti-reflection film has excellent scratch resistance, color unevenness is suppressed at a high level, and the anti-reflection layer has no repellency. I was able to.

It is a schematic sectional drawing which shows the antireflection film of one Example of this invention. It is a schematic sectional drawing which shows the polarizing plate which has the antireflection film of one Example of this invention. (A) And (b) is a schematic sectional drawing which shows the transmissive liquid crystal display which has the anti-reflective film of one Example of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the embodiments, the same components are denoted by the same reference numerals, and redundant description in the embodiments is omitted.

  FIG. 1 is a schematic cross-sectional view showing an antireflection film (10) according to an embodiment of the present invention.

  As shown in FIG. 1, the antireflection film (10) according to the embodiment of the present invention includes a transparent substrate (11), a hard coat layer (12), and an antireflection layer (13). An antireflection layer (13) is laminated on the hard coat layer (12) and the hard coat layer (12) on the material (11).

  In the present invention, the hard coat layer (12) is formed by applying a coating liquid containing an ionizing radiation curable material on the transparent substrate (11) and curing it by irradiation with ionizing radiation. Even in the antireflection layer (13), a coating liquid containing an ionizing radiation curable material is applied on the hard coat layer (12) and cured by irradiation with ionizing radiation. Thus, the hard coat layer (12) and the antireflection layer (13) are formed by a wet coating method using a coating liquid. By forming a hard coat layer and an antireflection film using the wet coating method, it is easier to increase the area, continuously produce, and reduce costs than when these layers are formed by the dry coating method. Can do. Further, in the antireflection film of the present invention, a hard coat layer and an antireflection layer are formed by a coating liquid containing an ionizing radiation curable material and a coating liquid coating and curing by irradiation with ionizing radiation. By using an ionizing radiation curable material and forming a hard coat layer and an antireflection layer by coating and curing, the hard coat layer and the antireflection layer can be made into a hard film, and the antireflection film surface is scratch resistant. Can be granted.

  Moreover, in the antireflection film of the present invention, the antireflection layer includes a surface conditioner having both or one of a fluorine-containing group and a silicone skeleton. By including a surface conditioner having either or both of a fluorine-containing group and a silicone skeleton, these surface conditioners are localized on the outermost surface of the antireflection layer and make the surface of the wet coating film uniform. At the same time, it provides slipperiness to the outermost surface of the antireflection layer, and is effective not only in preventing the occurrence of color unevenness but also in improving the scratch resistance.

  In the antireflection film of the present invention, the contact angle of pure water on the hard coat layer surface (12) measured by JIS R3257 (1999) is in the range of 60 ° to 90 °. . In the antireflection film of the present invention, the pure water contact angle on the surface of the hard coat layer before forming the antireflection film is 60 ° or more and 90 ° or less so that it has excellent scratch resistance and no color unevenness. And it was able to be set as the antireflection film without the repellency of an antireflection layer.

  In the antireflection film of the present invention, the film thickness (d) of the antireflection layer (13) is the optical film thickness (nd) obtained by multiplying the film thickness (d) by the refractive index (n) of the low refractive index layer. ) Is designed to be equal to ¼ of the wavelength (λ) of visible light. By setting the optical film thickness of the antireflection layer to λ / 4, an antireflection function can be imparted to the antireflection film surface by optical interference. The thickness of the antireflection layer is extremely thin. Further, as described above, the antireflection layer can provide an antireflection function by optical interference, and therefore, color unevenness due to film thickness variation of the antireflection film is likely to occur. In particular, when the antireflection layer is formed by a wet coating method, it is difficult to control the film thickness to be constant as compared with the dry coating method. In the antireflection film of the present invention, the pure water contact angle on the surface of the hard coat layer is 60 ° or more and 90 ° or less, so that it has excellent scratch resistance, no color unevenness, and repellency of the antireflection layer. There could be no anti-reflection film.

  In order to suppress the color unevenness at a high level, the present inventors have not only optimized the antireflection layer (coating liquid) but also an antireflection layer. The present inventors have found that it is necessary to optimize the surface state of the hard coat layer located in the lower layer of the present invention, and have arrived at the present invention.

  By setting the contact angle in the pure water on the surface of the hard coat layer (12) within the range of 60 ° or more and 90 ° or less, the surface conditioner existing in the antireflection layer is optimally localized, and scratch resistance and An antireflection film excellent in color unevenness can be provided. When the contact angle of pure water on the surface of the hard coat layer (12) is less than 60 °, the localization of the surface conditioner contained in the antireflection layer is not promoted, resulting in a decrease in scratch resistance and a deterioration in color unevenness. I will invite you. On the other hand, when the contact angle in the pure water on the surface of the hard coat layer (12) exceeds 90 °, the wettability of the coating liquid of the antireflection layer (13) on the surface of the hard coat layer (12) is deteriorated. When the coating liquid for forming the antireflection layer (13) is applied onto the hard coat layer (12) by the wet coating method, repelling and unevenness may occur. Further, even when no repellency or unevenness occurs, the interlayer adhesion between the hard coat layer (12) and the antireflection layer (13) does not appear, and the antireflection layer (13) peels off easily, resulting in scratch resistance. Sex is reduced.

  In the antireflection film of the present invention, it is more preferable that the contact angle of pure water on the surface of the hard coat layer measured by JIS R3257 (1999) is in the range of 70 ° to 80 °. When the contact angle of pure water on the surface of the hard coat layer is in the range of 70 ° or more and 80 ° or less, the scratch resistance can be made extremely high, and color unevenness can be suppressed at a very high level. be able to. In addition, the contact angle of the pure water on the hard coat layer surface measured by JIS R3257 (1999) is measured by a sessile drop method.

  For the method of indicating the condition of the hard coat surface, surface energy can be used. For measuring the surface energy, a method of measuring a contact angle using a plurality of reagents and calculating the value is known. In order to express the effect in the present invention, the contact angle is measured using pure water. Only is enough.

  Moreover, in the antireflection film of the present invention, it is preferable that the hard coat layer contains a surface conditioner having both or one of a fluorine-containing group and a silicone skeleton. When the hard coat layer contains a surface conditioner having either or both of a fluorine-containing group and a silicone skeleton, the contact angle of pure water on the hard coat layer surface can be easily optimized.

  The antireflection film of the present invention and the production method thereof will be described in detail.

  As the transparent substrate (11) of the antireflection film (10) according to the embodiment of the present invention, films or sheets made of various organic polymers can be used. For example, a transparent base material (11) usually used for optical members such as a display can be mentioned, and optical properties such as transparency and refractive index of light, as well as various physical properties such as impact resistance, heat resistance and durability. In consideration, polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate and polyethylene naphthalate, celluloses such as triacetylcellulose, diacetylcellulose and cellophane, polyamides such as 6-nylon and 6,6-nylon, An acrylic polymer such as polymethyl methacrylate, or an organic polymer such as polystyrene, polyvinyl chloride, polyimide, polyvinyl alcohol, polycarbonate, or ethylene vinyl alcohol is used. Among these, triacetyl cellulose can be particularly preferably used as the transparent substrate. Furthermore, it is possible to use those organic polymers that have been added with functions by adding additives such as ultraviolet absorbers, infrared absorbers, plasticizers, lubricants, colorants, antioxidants, flame retardants, and the like. it can.

  Next, a hard coat layer (12) is formed on the transparent substrate (11) by a wet coating method. The hard coat layer is formed by applying a coating liquid containing an ionizing radiation curable material on the transparent substrate (11) and curing it by irradiation with ionizing radiation.

  As the ionizing radiation curable material, a compound having an unsaturated bond can be used, and specifically, a compound having a (meth) acryl group can be used. Examples of the compound having a (meth) acrylic group as the ionizing radiation curable material include monofunctional or polyfunctional (meth) acrylate compounds such as acrylic acid or methacrylic acid ester of polyhydric alcohol, diisocyanate and polyhydric alcohol, and A polyfunctional urethane (meth) acrylate compound synthesized from a hydroxy ester of acrylic acid or methacrylic acid can be used. Besides these, as ionizing radiation type materials, polyether resins having an acrylate functional group, polyester resins, epoxy resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, and the like can be used. .

  In the present invention, “(meth) acrylic group” refers to both “acrylic group” and “methacrylic group”. Similarly, “(meth) acrylate” indicates both “acrylate” and “methacrylate”. For example, “urethane (meth) acrylate” indicates both “urethane acrylate” and “urethane methacrylate”.

  Examples of the monofunctional (meth) acrylate compound include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl ( (Meth) acrylate, t-butyl (meth) acrylate, glycidyl (meth) acrylate, acryloylmorpholine, N-vinylpyrrolidone, tetrahydrofurfuryl acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isobornyl (meth) ) Acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, benzyl (Meth) acrylate, 2-ethoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethyl carbitol (meth) acrylate, phosphoric acid (meth) acrylate, phenoxy (meth) acrylate, nonylphenol (meth) acrylate, methoxy Diethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, methoxypropylene glycol (meth) acrylate, 2- (meth) acryloyloxyethyl-2-hydroxypropyl phthalate, 2-hydroxy-3-phenoxypropyl (meth) acrylate 2- (meth) acryloyloxyethyl hydrogen phthalate, 2- (meth) acryloyloxypropyl hydrogen phthalate, 2- (meth) acryloyl Oxypropyl hexahydrohydrogen phthalate, 2- (meth) acryloyloxypropyl tetrahydro phthalate, dimethylaminoethyl (meth) acrylate, trifluoroethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, hexafluoropropyl (meth) acrylate Adamantane derivative mono (meth) acrylates such as adamantyl acrylate having monovalent mono (meth) acrylate derived from octafluoropropyl (meth) acrylate, octafluoropropyl (meth) acrylate, 2-adamantane and adamantanediol Can be mentioned.

  Examples of the bifunctional (meth) acrylate compound include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, hexanediol di (meth) acrylate, and nonanediol di (meth). ) Acrylate, ethoxylated hexanediol di (meth) acrylate, propoxylated hexanediol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol di (Meth) acrylate, neopentyl glycol di (meth) acrylate, ethoxylated neopentyl glycol di (meth) acrylate, tripropylene glycol Ruji (meth) acrylate, di (meth) acrylate, such as hydroxypivalic acid neopentyl glycol di (meth) acrylate.

  Examples of the trifunctional or higher functional (meth) acrylate compound include trimethylolpropane tri (meth) acrylate, ethoxylated trimethylolpropane tri (meth) acrylate, propoxylated trimethylolpropane tri (meth) acrylate, and tris 2-hydroxy. Ethyl isocyanurate tri (meth) acrylate, tri (meth) acrylate such as glycerin tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, ditrimethylolpropane tri (meth) acrylate, etc. Trifunctional (meth) acrylate compounds, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol te Trifunctional or higher polyfunctionality such as la (meth) acrylate, dipentaerythritol penta (meth) acrylate, ditrimethylolpropane penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, ditrimethylolpropane hexa (meth) acrylate ( Examples thereof include a (meth) acrylate compound and a polyfunctional (meth) acrylate compound obtained by substituting a part of these (meth) acrylates with an alkyl group or ε-caprolactone.

  Urethane (meth) acrylate is obtained by reacting a polyhydric alcohol, a polyvalent isocyanate, and a hydroxyl group-containing acrylate. Specifically, Kyoeisha Chemical Co., Ltd., UA-306H, UA-306T, UA-306l, etc., Nippon Synthetic Chemical Co., Ltd., UV-1700B, UV-6300B, UV-7600B, UV-7605B, UV-7640B, UV -7650B, etc., manufactured by Shin-Nakamura Chemical Co., Ltd., U-4HA, U-6HA, UA-100H, U-6LPA, U-15HA, UA-32P, U-324A, etc., manufactured by Daicel UCB, Ebecryl-1290, Ebecryl -1290K, Ebecryl-5129, etc., manufactured by Negami Kogyo Co., Ltd., UN-3220HA, UN-3220HB, UN-3220HC, UN-3220HS, etc. can be used, but not limited thereto.

  In the case of ionizing radiation curable materials, modified products of these (meth) acrylic group-containing compounds can also be used. Examples of the modified product include an ethylene oxide (EO) modified product and a propylene oxide (PO) modified product.

  As ionizing radiation curable materials, the hard coat layer (12) surface and antireflection layer (13) surface are scratch resistant by steel wool rubbing test, surface hardness by pencil scratch test, adhesion by adhesive tape peeling test, minimum bending Materials can be selected and used so as to satisfy the required specifications for various properties such as cracking properties by testing.

  In addition, a photopolymerization initiator is added to the coating liquid for forming the hard coat layer, if necessary. As the photopolymerization initiator, for example, acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, etc. may be used.

  Moreover, a solvent is added to the coating liquid for forming the hard coat layer as necessary. By adding a solvent, coating suitability can be improved. Solvents include aromatic hydrocarbons such as toluene, xylene, cyclohexane and cyclohexylbenzene, hydrocarbons such as n-hexane, dibutyl ether, dimethoxymethane, dimethoxyethane, diethoxyethane, propylene oxide, dioxane, dioxolane, and trioxane. , Ethers such as tetrahydrofuran, anisole and phenetole, and ketones such as methyl isobutyl ketone, methyl butyl ketone, acetone, methyl ethyl ketone, diethyl ketone, dipropyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, and methylcyclohexanone, Ethyl formate, propyl formate, n-pentyl formate, methyl acetate, ethyl acetate, methyl propionate, propion brewed ethyl, n-pentyl acetate, Ester, such as γ-ptyrolactone, cellosolves such as methyl cellosolve, cellosolve, butyl cellosolve, cellosolve acetate, alcohols such as methanol, ethanol, isopropyl alcohol, etc. Is done.

  Moreover, it is preferable that the coating liquid which forms a hard-coat layer contains the surface conditioning agent which has both a fluorine-containing group and a silicone frame | skeleton, or any one. The surface modifier is also called a leveling agent, an antifoaming agent, an interfacial tension modifier, or a surface tension modifier depending on its function, and all have a function of reducing the surface tension of the coating film to be formed. By adding this surface conditioner, it is possible to prevent the occurrence of coating film defects such as repellency and unevenness in the formed coating film. In order to adjust the contact angle in pure water on the surface of the hard coat layer (12), a surface conditioner can be suitably used. In general, the contact angle increases as the amount of the surface modifier added increases, and the contact angle decreases as the amount added decreases. In addition, the contact angle can be adjusted by the composition when the coating liquid for forming the hard coat layer (12) is adjusted, but the effect of the present invention is the same regardless of which method is used. Demonstrated.

  As the surface conditioner having a fluorine-containing group, a compound having a perfluoroalkyl group or a fluorinated alkenyl group in the main chain or side chain can be used. Specifically, BYK-340 manufactured by Big Chemie Japan Co., Ltd., Neoters Inc.'s Footgent 222F, DIC Co., Ltd. MegaFuck F-470, Osaka Organic Chemical Industry Co., Ltd. V-8FM, and the like can be used. It is not something.

  Specific examples of the surface conditioner having a silicone skeleton include BYK-300, BYK-306, BYK-307, BYK-310, BYK-315, BYK-322, BYK-323, manufactured by BYK Japan. BYK-325, BYK-330, BYK-331, BYK-333, BYK-337, BYK-341, BYK-344, BYK-345, BYK-347, BYK-348, BYK-349, BYK-370, BYK- 375, BYK-377, BYK-378, BYK-UV3500, BYK-UV3510, BYK-UV3570, BYK-Silclean3700, BYK-Silclean3720, Momentive TSF410, TSF411, TSF4700, TSF4701, XF42-B097 , TSF4730, YF3965, TSF4421, XF42-334, XF42-B3629, XF42-A3161, TSF4440, TSF4441, TSF4445, TSF4450, TSF4446, TSF4452, can be used TSF4460 like, but is not limited thereto.

  In order to impart an antistatic function to the antireflection film, a conductive agent may be added to the coating liquid for forming the hard coat layer. The conductive agent is not particularly limited, and examples thereof include a quaternary ammonium salt having an ion conduction mechanism, metal oxide fine particles having an electron conduction mechanism, and a π-conjugated conductive polymer. By adding these conductive agents to the hard coat layer, an antistatic function can be imparted to the surface of the antireflection film, and adhesion of dust or the like to the antireflection film surface due to charging can be prevented.

  In addition to the surface conditioner and the conductive agent, other additives may be added to the coating liquid for forming the hard coat layer. As the functional additive, an ultraviolet absorber, an infrared absorber, an adhesion improver, a curing agent, or the like can be used. Moreover, a thermoplastic resin can also be added to the coating liquid which forms a hard-coat layer.

  After applying the coating liquid for forming the hard coat layer obtained by adjusting the above-mentioned materials onto the transparent substrate (11) by the wet coating method and drying the coating film as necessary, ionizing radiation is used. A hard coat layer (12) is formed by irradiating a certain ultraviolet ray or electron beam. At this time, as the wet coating method, a coating method using a roll coater, a reverse roll coater, a gravure coater, a micro gravure coater, a knife coater, a bar coater, a wire bar coater, a die coater, or a dip coater can be used.

  Next, an antireflection layer (13) is formed on the hard coat layer (12). The antireflective layer is coated with a coating liquid containing a surface conditioning agent having an ionizing radiation curable material and / or a fluorine-containing group and / or a silicone skeleton on the hard coat layer (12) and cured by irradiation with ionizing radiation. Formed.

  As the ionizing radiation curable material contained in the coating liquid forming the antireflection layer, a compound having a (meth) acryl group can be used. Specifically, the materials exemplified in the section of ionizing radiation curable material contained in the coating liquid for forming the hard coat layer can be used.

  The surface conditioning agent that has both fluorine-containing groups and / or silicone skeleton contained in the coating solution that forms the antireflection layer is localized on the outermost surface of the antireflection layer, and the surface of the wet coating film is uniform. In addition to providing slipperiness to the outermost surface of the antireflection layer, it is effective not only in preventing the occurrence of color unevenness but also in improving the scratch resistance. Specifically, as a surface conditioner having either or both of a fluorine-containing group and a silicone skeleton contained in the coating liquid for forming the antireflection layer, surface conditioning contained in the coating liquid for forming the hard coat layer The materials exemplified in the section of the agent can be used.

  However, when a large amount of a surface conditioner is added to the coating liquid for forming the antireflection layer for the purpose of improving scratch resistance and color unevenness, the low refractive index component in the antireflection layer is relatively reduced. Will increase the reflectance.

  In the antireflection film of the present invention, the fluorine and silicon contents derived from the surface conditioning agent on the surface of the antireflection layer (13) are preferably in the range of 0.01 atom% or more and 10 atom% or less, respectively. When the content of fluorine and silicon derived from the surface adjusting agent on the antireflection layer surface is 0.01 atom% or less, the effect of the sufficient surface adjusting agent does not appear, and the deterioration of color unevenness and scratch resistance occurs. There is. On the other hand, when the fluorine and silicon contents derived from the surface adjusting agent are 10 atom% or more, the surface adjusting agent content in the antireflection layer becomes excessive, resulting in a problem that the surface of the antireflection layer floats in an oily state. Or the low refractive index component in the antireflection layer relatively decreases, and thus the refractive index of the antireflection layer increases and the antireflection function of the antireflection film decreases. .

  The fluorine and silicon contents derived from the surface conditioning agent on the antireflection layer surface can be determined by an X-ray photoelectron spectrometer (XPS).

  In an X-ray photoelectron spectrometer (XPS), when a sample is irradiated with X-rays of energy (hν), inner core electrons in the element are emitted by the photoelectric effect. The kinetic energy (Ek) of the photoelectron at this time is expressed by Ek = hν−Eb−φ. Here, Eb is the energy level of the inner core electron, which is a value unique to the element, and changes depending on the chemical state of the element. φ is the work function of the device or sample. Further, the distance that electrons can pass while maintaining energy in a solid is about several tens of kilometers. By measuring the Ek and the quantity of photoelectrons emitted from the sample surface with an X-ray photoelectron spectrometer (XPS), the type, content, and chemical state of the elements present to a depth of several tens of kilometers from the sample surface Can be analyzed.

  In addition, a photopolymerization initiator is added to the coating liquid for forming the antireflection layer as necessary. Specifically, the materials exemplified in the section of the photopolymerization initiator contained in the coating liquid for forming the hard coat layer can be used.

  Moreover, a solvent is added to the coating liquid for forming the antireflection layer as necessary. Specifically, the materials exemplified in the section of the solvent contained in the coating liquid for forming the hard coat layer can be used.

  If necessary, low refractive particles are added to the coating liquid for forming the antireflection layer. By including low refractive index particles in the formed antireflection layer, the refractive index of the antireflection layer can be lowered, the reflectance of the surface of the antireflection layer is lowered, and the antireflection function of the antireflection film is improved. Can be made.

The low-refractive particles are made of a low-refractive material such as LiF, MgF, 3NaF.AlF or AlF (all having a refractive index of 1.4), or Na ₃ AlF ₆ (cryolite, having a refractive index of 1.33). Although low refractive index particles can be used, in order to obtain better antireflection performance (low refractive index), particles having voids inside the particles can be suitably used. In the case of particles having voids inside the particles, the voids can be made to have a refractive index of air (≈1), so that they can be low refractive index particles having a very low refractive index. Specifically, porous silica particles and low refractive index silica particles having voids inside can be used.

  The low refractive index particles used for the antireflection layer preferably have a particle size of 1 nm to 100 nm. More preferably, the particle size is 30 nm or more and 70 nm or less. When the particle size exceeds 100 nm, light is remarkably reflected by Rayleigh scattering, the antireflection layer is whitened, and the transparency of the antireflection film tends to be lowered. On the other hand, when the particle size is less than 1 nm, problems such as non-uniformity of particles in the antireflection layer due to aggregation of particles occur.

  In addition to the surface conditioner and the low refractive index particles, other additives may be added to the coating liquid for forming the antireflection layer. As the functional additive, an ultraviolet absorber, an infrared absorber, an adhesion improver, a curing agent, or the like can be used.

  After applying the coating liquid for forming the antireflection layer obtained by adjusting the above-mentioned materials on the transparent substrate (11) by the wet coating method and drying the coating film as necessary, ionizing radiation is used. A hard coat layer (12) is formed by irradiating a certain ultraviolet ray or electron beam. At this time, as the wet coating method, a coating method using a roll coater, a reverse roll coater, a gravure coater, a micro gravure coater, a knife coater, a bar coater, a wire bar coater, a die coater, or a dip coater can be used.

  Next, a polarizing plate and a transmissive liquid crystal display using the antireflection film of the present invention will be described.

  FIG. 2 is a schematic cross-sectional view showing a polarizing plate (20) having an antireflection film (10) according to an embodiment of the present invention.

  In the polarizing plate (20) according to the embodiment of the present invention, the polarizing layer (22) and the transparent substrate (21) are provided on the surface of the transparent substrate (11) opposite to the surface on which the antireflection layer (13) is formed. In order.

  FIGS. 3A and 3B are schematic cross-sectional views showing a transmissive liquid crystal display (60, 70) having an antireflection film (10) according to an embodiment of the present invention. In the transmissive liquid crystal display (60) shown in FIG. 3A, a backlight unit (50), a polarizing plate (40), a liquid crystal cell (30), a polarizing plate (20), and a hard coat film (10) are sequentially arranged. I have. At this time, the formation side of the antireflection film (10) is the observation side, that is, the display surface.

  The backlight unit (50) includes a light source and a light diffusion plate. The liquid crystal cell (30) has a structure in which a TFT electrode is provided on one base material, an electrode and a color filter are provided on the other base material, and liquid crystal is sealed between both electrodes. In the polarizing plates (20) and (40) provided so as to sandwich the liquid crystal cell (30), the polarizing layer (22, 42) is sandwiched between the respective base materials (21, 23, 41, 43). It has a structure.

  A transmissive liquid crystal display (60) shown in FIG. 3 (a) includes a transparent substrate (11) of an antireflection film (10), a transparent substrate (21) and a transparent substrate (23) of a polarizing plate (20). A transmissive liquid crystal display (60) is provided separately. On the other hand, the transmissive liquid crystal display (70) shown in FIG. 3B is a transmissive liquid crystal display (70) having the polarizing plate (20) shown in FIG. 11) is provided with a polarizing layer (22) on the opposite side of the antireflection layer (13), and the transparent substrate (11) is a transparent substrate (10) and a polarizing substrate (20) transparent substrate (10). 21).

  Moreover, the transmissive liquid crystal display (60, 70) according to the embodiment of the present invention may include other functional members. Other functional members include, for example, a diffusion film, a prism sheet, a brightness enhancement film, a liquid crystal cell (30), and a polarizing plate (20, 40) for effectively using light emitted from the backlight unit (50). ) Retardation film for compensating for the retardation of the transmissive liquid crystal display (60, 70) according to the embodiment of the present invention is not limited thereto.

  Examples are shown below.

  First, coating liquids 1 to 6 (hard coating layer forming coating liquids 1 to 6) for forming a hard coat layer and coating liquids 1 to 3 (antireflection layer formation) for forming an antireflection layer as described below. Coating liquids 1 to 3) were prepared.

(Hardcoat layer forming coating solution 1)
For 100 parts by weight of urethane acrylate (UA-306H manufactured by Kyoeisha Chemical Co., Ltd.)
Dipentaerythritol hexaacrylate 50 parts by weight Pentaerythritol triacrylate 50 parts by weight Photopolymerization initiator (Ciba Japan, Irgacure 184) 10 parts by weight Alkyl polyether-modified silicone oil (Momentive, TSF4460) 0 .2 parts by weight · Methyl ethyl ketone 50 parts by weight · Methyl acetate 150 parts by weight was used to prepare hard coat layer forming coating solution 1.

(Hardcoat layer forming coating solution 2)
For 100 parts by weight of urethane acrylate (UA-306H manufactured by Kyoeisha Chemical Co., Ltd.)
-Dipentaerythritol hexaacrylate 50 parts by weight-Pentaerythritol triacrylate 50 parts by weight-Photopolymerization initiator (Ciba Japan, Irgacure 184) 10 parts by weight-Perfluoroalkyl group, hydrophilic group, lipophilic group-containing oligomer (Manufactured by DIC Corporation, MegaFuck F-470) A coating liquid 2 for forming a hard coat layer was prepared using 0.2 parts by weight, 50 parts by weight of methyl ethyl ketone, and 150 parts by weight of methyl acetate.

(Hard coat layer forming coating liquid 3)
For 100 parts by weight of urethane acrylate (UA-306H manufactured by Kyoeisha Chemical Co., Ltd.)
Dipentaerythritol hexaacrylate 50 parts by weight Pentaerythritol triacrylate 50 parts by weight Photopolymerization initiator (Ciba Japan, Irgacure 184) 10 parts by weight Alkyl polyether-modified silicone oil (Momentive, TSF4460) 0 .1 part by weight / perfluoroalkyl group / hydrophilic group / lipophilic group-containing oligomer (manufactured by DIC, Megafac F-470) 0.1 part by weight / methyl ethyl ketone 50 parts by weight / methyl acetate 150 parts by weight A coating solution 3 for forming a coat layer was prepared.

(Hard coat layer forming coating solution 4)
For 100 parts by weight of urethane acrylate (UA-306H manufactured by Kyoeisha Chemical Co., Ltd.)
Dipentaerythritol hexaacrylate 50 parts by weight Pentaerythritol triacrylate 50 parts by weight Photoinitiator (Ciba Japan, Irgacure 184) 10 parts by weight Alkyl polyether-modified silicone oil (Momentive, TSF4460) 4 The coating liquid 4 for forming a hard coat layer was prepared using 50 parts by weight, 50 parts by weight of methyl ethyl ketone, and 150 parts by weight of methyl acetate.

(Hardcoat layer forming coating solution 5)
For 100 parts by weight of urethane acrylate (UA-306H manufactured by Kyoeisha Chemical Co., Ltd.)
-Dipentaerythritol hexaacrylate 50 parts by weight-Pentaerythritol triacrylate 50 parts by weight-Photopolymerization initiator (Ciba Japan, Irgacure 184) 10 parts by weight-Perfluoroalkyl group, hydrophilic group, lipophilic group-containing oligomer (Manufactured by DIC Corporation, MegaFuck F-470) A coating solution 5 for forming a hard coat layer was prepared using 4 parts by weight, 50 parts by weight of methyl ethyl ketone, and 150 parts by weight of methyl acetate.

(Coating liquid 6 for forming hard coat layer)
For 100 parts by weight of urethane acrylate (UA-306H manufactured by Kyoeisha Chemical Co., Ltd.)
• 50 parts by weight of dipentaerythritol hexaacrylate • 50 parts by weight of pentaerythritol triacrylate • Photopolymerization initiator (Ciba Japan, Irgacure 184) 10 parts by weight • 100 parts by weight of methyl ethyl ketone • 300 parts by weight of methyl acetate A coating liquid 6 for forming a coat layer was prepared.

(Antireflection layer-forming coating solution 1)
-Porous silica fine particle dispersion (average particle diameter 50 nm, solid content 20%, solvent: methyl isobutyl ketone) 15 parts by weight-EO-modified dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., DPEA-12) 2 parts by weight Photopolymerization initiator (manufactured by Ciba Japan, Irgacure 184) 0.1 part by weight / perfluoroalkyl group / hydrophilic group / lipophilic group-containing oligomer (manufactured by DIC, MegaFuck F-470) 0.1 part by weight Was diluted with 82 parts by weight of methyl isobutyl ketone as a solvent to prepare a coating solution 1 for forming an antireflection layer.

(Antireflection layer-forming coating solution 2)
-Porous silica fine particle dispersion (average particle size 50 nm, solid content 20%, solvent: methyl isobutyl ketone) 15 parts by weight-EO-modified dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., DPEA-12) 2 parts by weight Photopolymerization initiator (manufactured by Ciba Japan, Irgacure 184) 0.1 part by weight / perfluoroalkyl group / hydrophilic group / lipophilic group-containing oligomer (manufactured by DIC, MegaFuck F-470) 0.5 part by weight Was diluted with 82 parts by weight of methyl isobutyl ketone as a solvent to prepare a coating solution 2 for forming an antireflection layer.

(Antireflection layer forming coating solution 3)
-Porous silica fine particle dispersion (average particle diameter 50 nm, solid content 20%, solvent: methyl isobutyl ketone) 15 parts by weight-EO-modified dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., DPEA-12) 2 parts by weight Photopolymerization initiator (manufactured by Ciba Japan Co., Ltd., Irgacure 184) Using 0.1 parts by weight, the coating solution 3 for forming an antireflection layer was prepared by diluting with 82 parts by weight of methyl isobutyl ketone as a solvent.

Example 1
(Formation of hard coat layer)
First, a 80 μm-thick triacetyl cellulose film (manufactured by Fuji Film) was prepared as a transparent substrate. Next, the coating liquid 1 for forming a hard coat layer is applied onto a transparent substrate, dried in an oven at 60 ° C. for 60 seconds, dried, and then irradiated using an ultraviolet irradiation device (Fusion UV System Japan, light source H bulb). A transparent hard coat layer (12) having a dry film thickness of 5 μm was formed by performing ultraviolet irradiation at a dose of 300 mJ / m ² .

(Formation of antireflection layer)
Coating solution 1 for forming an antireflection layer is applied on the formed hard coat layer, dried in an oven at 60 ° C. for 60 seconds, dried, and then irradiated with an ultraviolet ray irradiation device (Fusion UV System Japan, light source H bulb) in a nitrogen atmosphere. ) Was used to form an antireflection film having a dry film thickness of 0.1 μm by performing ultraviolet irradiation at an irradiation dose of 300 mJ / m ² .

(Example 2)
An antireflection film was obtained in the same manner as in (Example 1) except that the hard coat layer forming coating solution 2 was used.

(Example 3)
An antireflection film was obtained in the same manner as in (Example 1) except that the hard coat layer forming coating solution 3 was used.

Example 4
An antireflection film was obtained in the same manner as in Example 1 except that the coating liquid 2 for forming the antireflection layer was used.

(Comparative Example 1)
An antireflection film was obtained in the same manner as in Example 1 except that the hard coat layer forming coating solution 4 was used.

(Comparative Example 2)
An antireflection film was obtained in the same manner as in Example 1 except that the hard coat layer forming coating solution 5 was used.

(Comparative Example 3)
An antireflection film was obtained in the same manner as in (Example 1) except that the hard coat layer forming coating solution 6 was used.

(Comparative Example 4)
An antireflection film was obtained in the same manner as in Example 1 except that the coating liquid 3 for forming the hard coat layer was used and the coating liquid 3 for forming the antireflection layer was used.

The antireflection films obtained in (Example 1) to (Example 3) and (Comparative Example 1) to (Comparative Example 5) were evaluated by the following methods.

(Average luminous reflectance)
About the surface of the antireflection layer of the obtained antireflection film, the spectral reflectance at an incident angle of 5 ° was measured using an automatic spectrophotometer (manufactured by Hitachi, Ltd., U-4000). Further, the average luminous reflectance was obtained from the obtained spectral reflectance curve. In the measurement, a matte black paint was applied to the surface of the triacetylcellulose film, which is a transparent base material, on which the antireflection layer was not formed, and an antireflection treatment was performed. The results are shown in (Table 1).

(Abrasion resistance)
Steel wool “Bonster # 0000” (manufactured by Nippon Steel Wool) was rubbed 10 times each at a load of 200 g / cm ² and 500 g / cm ² to visually determine the presence or absence of scratches. The results are shown in (Table 1). In addition, criteria for determination are shown below.
Circle mark: Scratches cannot be confirmed.
Triangle mark: Scratches can be confirmed slightly.
X: Marks can be clearly seen.

(Color unevenness)
A matte black paint was applied to the surface of the obtained antireflection film where the antireflection layer was not formed, and after antireflection treatment, color unevenness was observed under a three-wavelength fluorescent lamp. The results are shown in (Table 1). In addition, criteria for determination are shown below.
Circle: No color unevenness is seen Triangle mark: Slight color unevenness is seen X: Clear color unevenness is seen

(Repel)
The surface of the antireflection layer of the obtained antireflection film was visually judged for the presence of repelling. In the measurement, a matte black paint was applied to the surface of the triacetylcellulose film, which is a transparent base material, on which the antireflection layer was not formed, and an antireflection treatment was performed. The results are shown in (Table 1).
Circle: Cannot confirm repellency.
Triangle mark: Slight repelling can be confirmed.
Cross: You can clearly see the repellency.

(Pure water contact angle)
About the surface of the antireflection layer of the obtained antireflection film, the contact angle of pure water was measured according to the sessile drop method described in JIS R3257 (1999). The results are shown in (Table 1).

(Fluorine content)
About the anti-reflective layer of the obtained anti-reflective film, fluorine content was measured using JEOL X-ray electron-spectral-analysis apparatus JSP-90MXV. The X-ray irradiation conditions in XPS measurement were an acceleration voltage of 10 kV and an emission current of 10 mA. The results are shown in (Table 1).

  As shown in (Table 1), in (Example 1) to (Example 4), anti-reflection films having high scratch resistance, suppressed color unevenness, and no repellency of the anti-reflection layer are obtained. It was confirmed that In addition, in the antireflection film of (Example 4), as a result of observing the surface of the antireflection film with the naked eye, it was confirmed that the surface conditioner was floated in an oily manner on the surface of the antireflection layer. In addition, it is confirmed from the antireflection films of (Example 1) to (Example 3) and (Comparative Example 1) to (Comparative Example 4) that the surface conditioner floats in an oily manner on the surface of the antireflection layer. There wasn't.

DESCRIPTION OF SYMBOLS 10 ... Antireflection film 11, 21, 23, 41, 43 ... Transparent base material 12 ... Hard-coat layer 13 ... Antireflection layer 20, 40 ... Polarizing plate 22, 42 ... Polarizing layer 30 ... Liquid crystal cell 40 ... Antireflection film 50 ... Backlight unit 60, 70 ... Transmission type liquid crystal display

Claims (6)

A film in which a hard coat layer and an antireflection layer are laminated in this order on at least one surface of a transparent substrate,
The hard coat layer is a coating liquid containing an ionizing radiation curable material applied on the transparent substrate and cured by irradiation with ionizing radiation, and
The antireflection layer was applied on the hard coat layer with a coating solution containing a surface conditioning agent having an ionizing radiation curable material and / or a fluorine-containing group and / or a silicone skeleton, and cured by irradiation with ionizing radiation. And
An antireflection film characterized in that the contact angle of pure water on the surface of the hard coat layer measured in accordance with JIS R3257 (1999) is in the range of 60 ° to 90 °.   The antireflection film according to claim 1, wherein the contact angle of pure water on the surface of the hard coat layer measured by JIS R3257 (1999) is in the range of 70 ° to 80 °.   The antireflection film according to claim 1, wherein the hard coat layer contains a surface conditioner having both or one of a fluorine-containing group and a silicone skeleton.   A polarizing plate comprising: the antireflection film according to any one of claims 1 to 3; and a polarizing layer and a transparent substrate film in order from the transparent substrate side on a non-formation surface of the transparent substrate of the antireflection film.   In order from the observer side, the polarizing plate according to claim 4, the liquid crystal cell, the second polarizing plate, and the backlight unit are provided in this order, and the antireflection layer is located on the outermost surface on the observer side. A transmissive liquid crystal display characterized by that. A method for producing a film in which a hard coat layer and an antireflection layer are laminated in this order on at least one surface of a transparent substrate,
Applying a coating liquid containing an ionizing radiation curable material on the transparent substrate and curing it by irradiation with ionizing radiation to form a hard coat layer;
An antireflection layer is formed by applying a coating liquid containing a surface conditioning agent having an ionizing radiation curable material and / or a fluorine-containing group and / or a silicone skeleton on the hard coat layer and curing it by irradiation with ionizing radiation. A process, and
Production of an antireflection film, wherein the contact angle of pure water on the surface of the hard coat layer measured by JIS R3257 (1999) before forming the antireflection layer is in the range of 60 ° to 90 °. Method.

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