JP2010215685A - Low refractive index coating agent and antireflection film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low refractive index coating agent in order to offer an antireflection film which has a satisfactory optical characteristics, mechanical characteristics and stain proofness and besides has no bleeding. <P>SOLUTION: The low refractive index coating agent contains low refractive index nano fine particles, (a) a (meth)acryloyloxy group-containing multifunctional fluorine monomer, (b) a (meth)acryloyloxy group-containing multifunctional monomer and (c) a (meth)acryloyloxy group-containing silicone compound, wherein a content of the low refractive index nano fine particles is 20-50 pts.wt. relative to 100 pts.wt. of (a), a content of (b) is 15-30 pts.wt. relative to 100 pts.wt. of (a), and a loading of (c) is 2-15 pts.wt. relative to 100 pts.wt. of (a). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a low refractive index coating agent for providing an antireflection film having sufficient optical properties, mechanical properties and antifouling properties and not bleeding, and an antireflection film using the same. The present invention also relates to a display such as a polarizing plate, a backlight member, an LCD, a PDP, a CRT, a projection display, and an EL display using the antireflection film.

  In general, a display is used in an environment where external light or the like enters regardless of whether the display is 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, it is essential to provide an antireflection function on the display surface or the like, and there is a demand for higher performance of the antireflection function and a combination of functions other than the antireflection function.

  In general, the antireflection function is obtained by forming an antireflection layer having a multilayer structure having a repeating structure of a high refractive index layer and a low refractive index layer made of a transparent material such as a metal oxide on a transparent substrate. These antireflection layers having a multilayer structure can be formed by a dry film forming method such as a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method. In the case of forming an antireflection layer using a dry film formation method, there is an advantage that the film thickness of the low refractive index layer and the high refractive index layer can be precisely controlled, but the film formation is performed in a vacuum. There is a problem that productivity is low and it is not suitable for mass production. On the other hand, as an antireflection layer forming method, attention is focused on the production of an antireflection layer by a wet film forming method using a coating liquid capable of increasing the area, continuously producing, and reducing the cost. In addition, as a prior art document, the following patent document 1 is illustrated.

JP 2008-106190 A

  In providing an antireflection layer, particularly a low refractive index layer by a wet film formation method, low refractive index particles are added to the coating liquid in order to make the formed low refractive index layer have a low refractive index. At this time, there arises a problem that the antireflection layer cannot obtain sufficient mechanical properties due to insufficient strength of the low refractive nanoparticle.

  Here, there has been proposed a method for improving the slipperiness of the surface by adding a fluorine-based material or a silicone-based material to the low-refractive index layer to improve the mechanical properties. By adding a fluorine-based material or a silicone-based material to the low refractive index layer, antifouling properties can be expected in addition to mechanical properties. However, if it is added too much, there are problems such as bleeding of the fluorine-based material or silicone-based material component, transfer of the component to the contacted substance, deterioration of the initial characteristics of the antireflection film, and contamination of the production line.

  Among them, when the coated surface of the antireflection film produced by roll-to-roll comes into contact with the other film (the back surface of the other antireflection film), a fluorine-based material or a silicone-based material is formed on the back surface of the antireflection film. The adhesion of this component not only deteriorates the film characteristics of the antireflection film, but also causes a serious problem in the subsequent processing steps.

  When an antireflection film is used as a display member, a polarizing plate is attached to the back surface of the display and an antireflection film is installed on the forefront of the display. Must have sufficient performance.

  The present invention provides a low refractive index coating agent for providing an antireflection film having sufficient optical properties, mechanical properties, and antifouling properties and does not bleed, and an antireflection film using the same. Another object is to provide a polarizing plate, a backlight member, and a display using the antireflection film.

The invention according to claim 1 has a low refractive index nanoparticle, a polyfunctional fluorine monomer having a (meth) acryloyloxy group, a polyfunctional monomer having a (meth) acryloyloxy group, and a (meth) acryloyloxy group. Containing a multifunctional silicone compound, and
The content of the low refractive index nanoparticles is in the range of 20 to 50 parts by weight with respect to 100 parts by weight of the polyfunctional fluorine monomer having the (meth) acryloyloxy group, and
The content of the polyfunctional monomer having a (meth) acryloyloxy group with respect to 100 parts by weight of the polyfunctional fluorine monomer having the (meth) acryloyloxy group is in the range of 15 parts by weight or more and 30 parts by weight or less, and,
The addition amount of the polyfunctional silicone compound having a (meth) acryloyloxy group is in the range of 2 parts by weight or more and 15 parts by weight or less with respect to 100 parts by weight of the polyfunctional fluorine monomer having the (meth) acryloyloxy group. ,
This is a low refractive index coating agent.

  The invention described in claim 2 is an antireflection film characterized in that a low refractive index layer is provided by applying the low refractive index coating agent according to claim 1 on a transparent substrate.

  The invention according to claim 3 is the antireflection film according to claim 2, wherein the refractive index of the low refractive index layer is in the range of 1.32 to 1.40.

  The invention according to claim 4 is the antireflection film according to claim 3, wherein a hard coat layer is provided between the transparent substrate and the low refractive index layer.

  The invention according to claim 5 is the antireflection film according to claim 4, wherein the hard coat layer is made of a polymer mainly composed of a polyfunctional monomer having a (meth) acryloyloxy group. is there.

  The invention according to claim 6 is the antireflection film according to any one of claims 3 to 5, wherein the transparent substrate is a triacetyl cellulose film.

  The invention according to claim 7 is characterized in that the average luminous reflectance of the antireflection film is in the range of 0.4% to 0.8%. This is an antireflection film.

  The invention according to claim 8 is the antireflection according to any one of claims 3 to 7, wherein the water contact angle of the surface of the low refractive index layer of the antireflection film is 90 ° or more and 135 ° or less. It is a film.

  The invention according to claim 9 is a polarizing plate comprising the antireflection film according to any one of claims 3 to 8.

  Invention of Claim 10 is a backlight member provided with the antireflection film in any one of Claims 3-8.

  Invention of Claim 11 is a display provided with the antireflection film in any one of Claims 3-8.

  According to the present invention, it is possible to provide a low refractive index coating agent for providing an antireflection film having sufficient optical properties, mechanical properties, and antifouling properties and that does not bleed, and an antireflection film using the same. it can. Moreover, according to this invention, the polarizing plate, backlight member, and display using this antireflection film can be provided.

FIG. 1 is an explanatory cross-sectional view of an antireflection film using the low refractive index coating agent of the present invention. FIG. 2 is an explanatory sectional view of a polarizing plate provided with an antireflection film using the low refractive index coating agent of the present invention.

  The low refractive index coating agent of the present invention will be described.

  In the low refractive index coating agent of the present invention, low refractive index nanoparticles, polyfunctional fluorine monomer having (meth) acryloyloxy group, polyfunctional monomer having (meth) acryloyloxy group, (meth) acryloyl It contains a polyfunctional silicone compound having an oxy group.

As the low refractive index nanoparticles contained in the low refractive index coating agent of the present invention, LiF, MgF, 3NaF · AlF or AlF (all having a refractive index of 1.4), or Na ₃ AlF ₆ (cryolite, Low refractive index particles made of a low refractive material such as a refractive index of 1.33) and silica can be used. Moreover, the particle | grains which have a space | gap inside a particle | grain can be used suitably. 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 nanoparticle used in the low refractive index coating agent of the present invention preferably has a particle size of 1 nm to 100 nm. When the particle diameter exceeds 100 nm, light is remarkably reflected by Rayleigh scattering, and the low refractive index layer tends to be 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 particle aggregation in the low refractive index layer due to particle aggregation occur.

  Examples of the polyfunctional fluorine monomer having a (meth) acryloyloxy group used in the low refractive index coating agent of the present invention include 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3,3. -Pentafluoropropyl (meth) acrylate, 2- (perfluorobutyl) ethyl (meth) acrylate, 2- (perfluorohexyl) ethyl (meth) acrylate, 2- (perfluorooctyl) ethyl (meth) acrylate, 2- (Perfluorodecyl) ethyl (meth) acrylate, methyl α-trifluoromethacrylate, ethyl α-trifluoromethacrylate and the like can be mentioned.

  Examples of the polyfunctional monomer having a (meth) acryloyloxy group used in the low refractive index coating agent of the present invention include 1,4-butanediol (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neo Pentyl glycol (meth) acrylate, ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, 3-methylpentadiol di (meth) ) Acrylate, diethylene glycol bis β- (meth) acryloyloxypropinate, trimethylolethane tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) a Relate, dipentaerythritol hexa (meth) acrylate, tri (2-hydroxyethyl) isocyanate di (meth) acrylate, pentaerythritol tetra (meth) acrylate, 2,3-bis (meth) acryloyloxyethyloxymethyl [2.2 .1] Heptane, poly 1,2-butadiene di (meth) acrylate, 1,2-bis (meth) acryloyloxymethylhexane, nonaethylene glycol di (meth) acrylate, tetradecanethylene glycol di (meth) acrylate, 10- Decanediol (meth) acrylate, 3,8-bis (meth) acryloyloxymethyltricyclo [5.2.10] decane, hydrogenated bisphenol A di (meth) acrylate, 2,2-bis (4- (meth) Acryloyloxy Diethoxyphenyl) propane, 1,4-bis ((meth) acryloyloxymethyl) cyclohexane, hydroxypivalate ester neopentyl glycol di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, ethoxy modified bisphenol A di A (meth) acrylate etc. can be mentioned.

  The polyfunctional silicone compound having a (meth) acryloyloxy group used in the low refractive index coating agent of the present invention includes a (poly) ester (meth) acrylate group, a urethane (meth) acrylate group, and an epoxy (meth) acrylate group. , (Poly) ether (meth) acrylate group, alkyl (meth) acrylate group or alkylene (meth) acrylate group, (meth) acrylate group having aromatic ring, and (meth) acrylate group having alicyclic structure Etc.

  In the low refractive index coating agent of the present invention, the content of the low refractive index nanoparticles is 20 parts by weight or more and 50 parts by weight with respect to 100 parts by weight of the polyfunctional fluorine monomer having a (meth) acryloyloxy group. The content of the polyfunctional monomer having a (meth) acryloyloxy group is 15 to 30 parts by weight with respect to 100 parts by weight of the polyfunctional fluorine monomer having a (meth) acryloyloxy group within the following range. The addition amount of the polyfunctional silicone compound having a (meth) acryloyloxy group is 2 parts by weight or more with respect to 100 parts by weight of the polyfunctional fluorine monomer having a (meth) acryloyloxy group. It is within the range of 15 parts by weight or less.

In the low refractive index coating agent of the present invention, the addition amount of the low refractive index nanoparticles is 20 parts by weight or more and 50 parts by weight with respect to 100 parts by weight of the polyfunctional fluorine monomer having a (meth) acryloyloxy group. Within the range of parts. This is because if it is less than 20 parts by weight, the average luminous reflectance is 0.8% or more, and if it exceeds 50 parts by weight, the mechanical properties (scratch resistance) are reduced to 200 g / cm ² or less. is there.

In the low refractive index coating agent of the present invention, the polyfunctional monomer having a (meth) acryloyloxy group is added to 100 parts by weight of the polyfunctional fluorine monomer having a (meth) acryloyloxy group. The amount added is in the range of 15 to 30 parts by weight. This is because if it is less than 15 parts by weight, the mechanical properties (scratch resistance) become 200 g / cm ² or less, and if it exceeds 30 parts by weight, the average luminous reflectance becomes 0.8% or more.

  Moreover, with respect to 100 parts by weight of the polyfunctional fluorine monomer having a (meth) acryloyloxy group, the amount of the polyfunctional silicone compound having a (meth) acryloyloxy group is from 2 parts by weight to 15 parts by weight. Within range. This is because if it is less than 2 parts by weight and more than 15 parts by weight, the antifouling property is deteriorated and the wiping property of the magic ink is deteriorated.

  In addition, a solvent and various additives can be added to a low refractive index coating agent as needed. 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 methyl isobutyl ketone, methyl butyl ketone, acetone, methyl ethyl ketone, diethyl ketone, dipropyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, methylcyclohexanone, and diacetone alcohol Ketones, ethyl formate, propyl formate, n-pentyl formate, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate Suitable for coating from esters such as n-pentyl acetate and γ-ptyrolactone, cellosolves such as methyl cellosolve, cellosolve, butyl cellosolve, cellosolve acetate, alcohols such as methanol, ethanol, isopropyl alcohol, water, etc. Etc. are selected as appropriate. In addition, a surface adjusting agent, a leveling agent, a refractive index adjusting agent, an adhesion improver, a photosensitizer, and the like can be added as additives to the low refractive index coating agent.

  In addition, when forming a low refractive index layer by irradiating ultraviolet rays using a low refractive index coating agent, a photopolymerization initiator is added to the low refractive index coating agent. Examples of the photopolymerization initiator include acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, and the like.

  Next, a method for producing an antireflection layer using the low refractive index coating agent of the present invention will be described.

  In the present invention, a low refractive index layer can be formed by applying a low refractive index layer on a transparent substrate, drying it, and irradiating it with ionizing radiation.

  In the antireflection film, a single-layer antireflection layer composed of a single low refractive index layer or a laminated antireflection layer composed of a repeating structure of a low refractive index layer and a high refractive index layer is formed. It is known. The antireflection film of the present invention preferably has a low refractive index layer single layer structure. Moreover, as a method of forming the antireflection layer, a method of applying the low refractive index coating agent of the present invention on a transparent substrate is preferable.

  When forming an antireflection layer with a laminated structure consisting of a repeating structure of a low refractive index layer and a high refractive index layer, it is necessary to precisely control the film thickness of the high refractive index layer and low refractive index layer to be formed. It is necessary to form by a vacuum film forming method. In the antireflection film of the present invention, for example, an antireflection film can be produced at low cost by forming a single layer structure of a low refractive index layer by a wet film formation method.

  At this time, in the low refractive index layer single layer, the optical film thickness (nd) obtained by multiplying the film thickness (d) by the refractive index (n) of the low refractive index layer is 1/4 of the wavelength of visible light. Designed to be equal.

  In the present invention, the low refractive index layer formed from the low refractive index coating agent preferably has a refractive index in the range of 1.32 to 1.40. By making the refractive index of the low refractive index layer in the range of 1.32 or more and 1.40 or less, the antireflection function can be imparted to the antireflection film. When the refractive index of the low refractive index layer exceeds 1.40, the resulting antireflection film may not be able to obtain a sufficient antireflection function. On the other hand, when the refractive index of the low refractive index layer is lower than 1.32, it is necessary to add a large amount of low refractive index nanoparticles to the low refractive index coating agent. (Abrasion performance) may be reduced.

  As a coating method for applying the low refractive index coating agent on the transparent substrate, a coating method using a roll coater, a reverse roll coater, a gravure coater, a knife coater, a bar coater, or a die coater can be used.

  A low refractive index layer is formed by irradiating the coating film obtained by applying a low refractive index coating agent on a transparent substrate with ionizing radiation. As the ionizing radiation, ultraviolet rays and electron beams can be used. In the case of ultraviolet curing, a light source such as a high pressure mercury lamp, a low pressure mercury lamp, an ultrahigh pressure mercury lamp, a metal halide lamp, a carbon arc, or a xenon arc can be used. In the case of electron beam curing, electron beams emitted from various electron beam accelerators such as cockloftwald type, bandegraph type, resonant transformer type, insulated core transformer type, linear type, dynamitron type, and high frequency type can be used. .

  As the transparent substrate of the present invention, films or sheets made of various organic polymers can be used. For example, a base material usually used for an optical member such as a display can be cited, considering optical properties such as transparency and refractive index of light, and further various physical properties such as impact resistance, heat resistance and durability, Polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate and polyethylene naphthalate, celluloses such as triacetyl cellulose, diacetyl cellulose and cellophane, polyamides such as 6-nylon and 6,6-nylon, polymethyl methacrylate, etc. Those made of organic polymers such as acrylic, polystyrene, polyvinyl chloride, polyimide, polyvinyl alcohol, polycarbonate, ethylene vinyl alcohol are used. In particular, polyethylene terephthalate, triacetyl cellulose, polycarbonate, and polymethyl methacrylate are preferable. Furthermore, functions can be added to these organic polymers by adding known additives such as antistatic agents, ultraviolet absorbers, infrared absorbers, plasticizers, lubricants, colorants, antioxidants, flame retardants, etc. Can also be used. The transparent substrate may be composed of one or a mixture of two or more selected from the above organic polymers, or a polymer, or may be a laminate of a plurality of layers.

  Especially, since a triacetylcellulose film has little birefringence and favorable transparency, when using the antireflection film of this invention for a liquid crystal display, it can be used conveniently. The refractive index of the triacetyl cellulose film is about 1.50, which is lower than that of other transparent substrates. For example, a polyethylene terephthalate film widely used as a transparent substrate is about 1.60.

FIG. 1 is an explanatory sectional view of an antireflection film using the low refractive index coating agent of the present invention.
In the antireflection film of the present invention, a hard coat layer 12 and a low refractive index layer 13 are sequentially provided on a transparent substrate 11. In the antireflection film of the present invention, it is preferable to provide a hard coat layer 12 between the transparent substrate 11 and the low refractive index layer 13. By providing the hard coat layer 12, an antireflection film excellent in scratch resistance can be obtained.

  In the antireflection film of the present invention, the hard coat layer is preferably made of a polymer containing a functional monomer having a (meth) acryloyloxy group as a main component.

  Functional monomers having a (meth) acryloyloxy group include pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipenta Erythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer, pentaerythritol triacrylate toluene diisocyanate urethane prepolymer, pentaerythritol triacrylate Name isophorone diisocyanate urethane prepolymer, etc. It can be.

  In the antireflection film of the present invention, a coating liquid containing a functional monomer having a (meth) acryloyloxy group is applied onto a transparent substrate, dried as necessary, and ionizing radiation. A hard coat layer is formed by irradiation.

  In the antireflection film of the present invention, the average luminous reflectance at the surface of the low refractive index layer is preferably from 0.4% to 0.8%. The lower the average luminous reflectance of the surface of the low refractive index layer, the better the antireflection function. When the average luminous reflectance on the surface of the low refractive index layer exceeds 0.8%, it becomes impossible to obtain an antireflection film having a sufficient antireflection function. On the other hand, it is difficult to realize an antireflection film having an average luminous reflectance of less than 0.4% on the surface of the low refractive index layer with a single low refractive index layer. The spectral reflectance of the antireflective film of the present invention is obtained after the surface opposite to the low refractive index layer of the antireflective film is matted with black paint, and is incident from the direction perpendicular to the surface of the low refractive index layer. The angle is set to 5 degrees, a C light source is used as the light source, and the angle is obtained under the condition of a 2 degree visual field. The average luminous reflectance is a reflectance value obtained by calibrating the reflectance of each wavelength of visible light with the relative luminous sensitivity and averaging it. At this time, the photopic standard relative visual sensitivity is used as the specific visual sensitivity.

  The water contact angle on the surface of the low refractive index layer of the antireflection film of the present invention is preferably 90 ° or more and 135 ° or less. By setting the water contact angle on the surface of the low refractive index layer to 90 ° or more, an antireflection film having sufficient antifouling performance can be obtained. If the water contact angle exceeds 135 °, it may not be possible to obtain an antireflection film having sufficient scratch resistance.

  The antireflection film of the present invention can be suitably used for the display surface. Examples of the display include LCD, PDP, CRT, projection display, EL display and the like. It can also be used inside a display. The case where the antireflection film of the present invention is used as a member of a liquid crystal display will be described below.

FIG. 2 shows an explanatory cross-sectional view of a polarizing plate provided with an antireflection film using the low refractive index coating agent of the present invention.
In the polarizing plate 2 of the present invention, the polarizing layer 22 and the transparent substrate 21 are sequentially provided on the surface of the transparent substrate 11 opposite to the surface on which the hard coat layer 12 is formed. The polarizing plate 2 of the present invention has a structure in which a polarizing layer 22 is sandwiched between two transparent substrates 11 and 21.

  The transmissive liquid crystal display includes a backlight unit, a polarizing plate, a liquid crystal cell, a polarizing plate, and an antireflection film in this order. At this time, the antireflection layer forming surface side of the antireflection film becomes the observation side, that is, the display surface.

  The backlight unit includes a light source and a light diffusing plate. The liquid crystal cell has a structure in which an electrode is provided on one transparent substrate, an electrode and a color filter are provided on the other transparent substrate, and liquid crystal is sealed between both electrodes. The polarizing plate provided so as to sandwich the liquid crystal cell has a structure in which a polarizing layer is sandwiched between transparent substrates.

  In addition, the transmissive liquid crystal display may include other functional members. Other functional members include, for example, a diffusion film, a prism sheet, a brightness enhancement film for effectively using light emitted from a backlight, and a phase difference film for compensating for a phase difference between a liquid crystal cell and a polarizing plate. However, the transmissive liquid crystal display is not limited to these. In addition, these can use a well-known thing.

  EXAMPLES The present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

  According to the following <Adjustment Example 1> <Adjustment Example 2> <Adjustment Example 3> <Adjustment Example 4>, the low refractive index coating agent is adjusted. <Example 1> <Example 2> <Example 3 >> An antireflection film was prepared according to <Example 4>.

<Adjustment example 1>
(Low refractive index coating agent)
35 parts by weight of low refractive index nanoparticle dispersion (average particle size 50 nm, solid content 20%, solvent: methyl isobutyl ketone) with respect to 100 parts by weight of polyfunctional fluorine monomer having (meth) acryloyloxy group ( As the nanoparticulate solid content), the addition amount of the polyfunctional monomer having a (meth) acryloyloxy group is 15 parts by weight, and the addition amount of the polyfunctional silicone compound having a (meth) acryloyloxy group is 6 parts by weight. Then, methyl isobutyl ketone (MIBK): diacetone alcohol (DAA) = 85: 15 was added to prepare a coating solution for forming a 4 wt% low refractive index layer.

<Example 1>
(Formation of a low refractive index layer)
A low refractive index coating agent is applied onto a triacetylcellulose film (Fuji Film: film thickness: 80 μm) having a hard coat layer obtained by curing a polyfunctional monomer having a (meth) acryloyloxy group, and 70 ° C./60 seconds. It dried in oven and apply | coated so that a film thickness might be set to 100 nm. After drying, under a nitrogen purge, an ultraviolet irradiation device (Fusion UV System Japan, light source H bulb) is used to cure by ultraviolet irradiation at an irradiation dose of 380 mJ / m ² to form a low refractive index layer. Produced.

<Adjustment example 2>
(Low refractive index coating agent)
In the same manner as in Example 1, with respect to 100 parts by weight of a polyfunctional fluorine monomer having a (meth) acryloyloxy group, a low refractive index nanoparticle dispersion (average particle size 50 nm, solid content 20%, solvent: Methyl isobutyl ketone) 35 parts by weight (as the amount of solids of nano-particles), addition amount of polyfunctional monomer having (meth) acryloyloxy group, addition amount of polyfunctional silicone compound having (meth) acryloyloxy group A liquid was prepared by combining 6 parts by weight, and MIBK: DAA = 85: 15 was added to prepare a coating solution for forming a 4 wt% low refractive index layer.

<Example 2>
(Formation of a low refractive index layer)
A low refractive index coating agent is applied onto a triacetylcellulose film (Fuji Film: film thickness: 80 μm) having a hard coat layer obtained by curing a polyfunctional monomer having a (meth) acryloyloxy group, and 70 ° C./60 seconds. It dried in oven and apply | coated so that a film thickness might be set to 100 nm. After drying, under a nitrogen purge, an ultraviolet irradiation device (Fusion UV System Japan, light source H bulb) is used to cure by ultraviolet irradiation at an irradiation dose of 380 mJ / m ² to form a low refractive index layer. Produced.

<Adjustment example 3>
(Low refractive index coating agent)
In the same manner as in Example 1, with respect to 100 parts by weight of a polyfunctional fluorine monomer having a (meth) acryloyloxy group, a low refractive index nanoparticle dispersion (average particle size 50 nm, solid content 20%, solvent: Methyl isobutyl ketone) 35 parts by weight (as the amount of solids of nanoparticle), addition amount of polyfunctional monomer having (meth) acryloyloxy group, addition amount of polyfunctional silicone compound having (meth) acryloyloxy group A liquid was prepared by combining 6 parts by weight, and MIBK: DAA = 85: 15 was added to prepare a coating solution for forming a 4 wt% low refractive index layer.

<Example 3>
A low refractive index coating agent is applied onto a triacetylcellulose film (Fuji Film: film thickness: 80 μm) having a hard coat layer obtained by curing a polyfunctional monomer having a (meth) acryloyloxy group, and 70 ° C./60 seconds. It dried in oven and apply | coated so that a film thickness might be set to 100 nm. After drying, under a nitrogen purge, an ultraviolet irradiation device (Fusion UV System Japan, light source H bulb) is used to cure by ultraviolet irradiation at an irradiation dose of 380 mJ / m ² to form a low refractive index layer. Produced.

<Adjustment example 4>
(Low refractive index coating agent)
In the same manner as in Example 1, with respect to 100 parts by weight of a polyfunctional fluorine monomer having a (meth) acryloyloxy group, a low refractive index nanoparticle dispersion (average particle size 50 nm, solid content 20%, solvent: Methyl isobutyl ketone) 35 parts by weight (as the amount of solids of nano-particles), addition amount of polyfunctional monomer having (meth) acryloyloxy group, addition amount of polyfunctional silicone compound having (meth) acryloyloxy group A liquid was prepared by combining 6 parts by weight, and MIBK: DAA = 85: 15 was added to prepare a coating solution for forming a 4 wt% low refractive index layer.

<Example 4>
(Formation of a low refractive index layer)
A low refractive index coating agent is applied onto a triacetylcellulose film (Fuji Film: film thickness: 80 μm) having a hard coat layer obtained by curing a polyfunctional monomer having a (meth) acryloyloxy group, and 70 ° C./60 seconds. It dried in oven and apply | coated so that a film thickness might be set to 100 nm. After drying, under a nitrogen purge, an ultraviolet irradiation device (Fusion UV System Japan, light source H bulb) is used to cure by ultraviolet irradiation at an irradiation dose of 380 mJ / m ² to form a low refractive index layer. Produced.

  The antireflection film obtained in the above examples was evaluated by the following method.

(1) Optical characteristics <Spectral reflectance / Average luminous reflectance / Refractive index>
About the surface of the low refractive index 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). Moreover, the average luminous reflectance and refractive index were calculated | required 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 substrate, on which the low refractive index layer was not formed, and an antireflection treatment was performed.
<Haze value and total light transmittance>
About the obtained anti-reflective film, the haze value and the total light transmittance were measured using the image clarity measuring device [Nippon Denshoku Industries Co., Ltd. make, NDH-2000].

(2) Antifouling property <Contact angle measurement>
Using a contact angle meter (CA-X type: manufactured by Kyowa Interface Science Co., Ltd.), create a droplet of 0.9 μl at the tip of the needle and make it into contact with the surface of the substrate (solid). It was. The contact angle is an angle formed by the solid surface and the tangent to the liquid surface at the point where the solid and the liquid are in contact with each other, and is defined as the angle containing the liquid. Distilled water was used as the liquid.
<Wipeability of oil-based pens (Mackey, Magic)>
The oil-based pen adhering to the surface of the low refractive index layer was wiped off with a tissue paper (Erière: Co., Ltd.), and the ease of removal was visually evaluated. Judgment criteria are shown below.
○: The oil pen can be easily wiped off.
Δ: The oil pen can be wiped off.
X: The oil-based pen cannot be wiped off.

(3) Mechanical properties <Abrasion resistance test>
The surface of the low refractive index layer was rubbed 10 times with steel wool (Bonster # 0000: manufactured by Nippon Steel Wool Co., Ltd.) at 200 g / cm ² , 300 g / cm ² , 400 g / cm ² , and 500 g / cm ² , with or without scratches Was visually evaluated (steel wool test). Judgment criteria are shown below.
○: No scratch ×: Scratch

(4) Bleed The coated surface was wiped with tissue paper [Erière: manufactured by Co., Ltd.] and visually evaluated whether it could be wiped off. Judgment criteria are shown below.
○: No bleed (cannot be wiped off)
×: Bleed (can be wiped off)

  Table 1 shows the evaluation results.

  As shown in Table 1, all of Examples 1, 2, 3, and 4 have low reflectivity, and an intended low refractive index layer that does not bleed can be obtained. In addition, Example 1, Example 2, Example 3, and Example 4 in which the amount of the functional monomer having a (meth) acryloyloxy group was changed to 15 parts by weight, 20 parts by weight, 25 parts by weight, and 30 parts by weight were compared. It can be seen that the scratch resistance was improved as the amount of dendrimer was increased.

  The antireflection film of the present invention comprises a low refractive index nanoparticle, a polyfunctional fluorine monomer having a (meth) acryloyloxy group, a polyfunctional monomer having a (meth) acryloyloxy group, a (meth) acryloyl By adding a polyfunctional silicone compound having an oxy group, it has a low refractive index optical property with an average luminous reflectance of 0.8% or less, excellent antifouling properties, and excellent mechanical strength. A prevention film can be formed. That is, the antireflection film of the present invention is excellent in being disposed on the outermost layer of a display or the like.

DESCRIPTION OF SYMBOLS 1 Antireflection film 11 Transparent base material 12 Hard-coat layer 13 Low refractive index layer 2 Polarizing plate 21 Transparent base material 22 Polarizing layer

Claims (11)

Containing low refractive index nanoparticles, polyfunctional fluorine monomer having (meth) acryloyloxy group, polyfunctional monomer having (meth) acryloyloxy group, polyfunctional silicone compound having (meth) acryloyloxy group, and,
The content of the low refractive index nanoparticles is in the range of 20 to 50 parts by weight with respect to 100 parts by weight of the polyfunctional fluorine monomer having the (meth) acryloyloxy group, and
The content of the polyfunctional monomer having a (meth) acryloyloxy group with respect to 100 parts by weight of the polyfunctional fluorine monomer having the (meth) acryloyloxy group is in the range of 15 parts by weight or more and 30 parts by weight or less, and,
The addition amount of the polyfunctional silicone compound having a (meth) acryloyloxy group is in the range of 2 parts by weight or more and 15 parts by weight or less with respect to 100 parts by weight of the polyfunctional fluorine monomer having the (meth) acryloyloxy group. ,
A low refractive index coating agent characterized by that.   An antireflective film, wherein a low refractive index layer is provided by applying the low refractive index coating agent according to claim 1 on a transparent substrate.   The antireflective film according to claim 2, wherein a refractive index of the low refractive index layer is in a range of 1.32 to 1.40.   The antireflection film according to claim 3, wherein a hard coat layer is provided between the transparent substrate and the low refractive index layer.   The antireflection film according to claim 4, wherein the hard coat layer is made of a polymer mainly composed of a polyfunctional monomer having a (meth) acryloyloxy group.   The antireflection film according to claim 3, wherein the transparent substrate is a triacetyl cellulose film.   The antireflection film according to claim 3, wherein an average luminous reflectance of the antireflection film is in a range of 0.4% to 0.8%.   The antireflection film according to any one of claims 3 to 7, wherein a water contact angle of the surface of the low refractive index layer of the antireflection film is 90 ° or more and 135 ° or less.   A polarizing plate comprising the antireflection film according to claim 3.   A backlight member provided with the antireflection film according to claim 3.   A display provided with the antireflection film according to claim 3.

Images