JP2009075576A - Method for producing antireflection film, image display device and coating composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing an antireflection film with excellent productivity, which a method for producing an antireflection film having excellent antireflection property without carrying out a complicated step, and an image display device, and to provide an image display device having excellent scratch resistance and alkali resistance and further having antireflection property. <P>SOLUTION: The method for producing an antireflection film comprising two layers different in refractive index includes applying, drying and curing a coating composition containing two or more kinds of inorganic particles, wherein at least one kind of inorganic particle is surface-treated with a fluorine compound and the coating composition contains an alkylphenone derivative. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an antireflection film production method, an antireflection film produced using the production method, an image display device including the antireflection film, and a coating composition suitable for the production method.

  In general, an antireflection film prevents contrast reduction and image reflection due to reflection of external light in an image display device such as a cathode ray tube display (CRT), a plasma display panel (PDP), and a liquid crystal display (LCD). Therefore, it is placed on the outermost surface of the display so as to reduce the reflectivity using the principle of optical interference.

  As the antireflection film, a film made of a low refractive index material whose refractive index is smaller than that of a substrate such as a film is usually used. As such an antireflection coating, for example, a method of forming a low refractive index material layer on the surface of a substrate such as a film by vapor deposition or sputtering is known, but it is necessary to form it in a vacuum or in an inert gas atmosphere. Therefore, there has been a problem that the operation is complicated (see Patent Document 1).

  As a solution to the above-mentioned problem, a film formed by curing a compound capable of providing a cured film having a low refractive index is known. This is formed by applying an antireflection film-forming composition containing a compound capable of giving a cured film having a low refractive index to the surface of a supporting substrate such as a film and then curing the composition. Since the operation for forming is simple, it is widely used (see Patent Document 2).

  On the other hand, in order to reduce the reflectance in a wider wavelength region as an antireflection film, a multilayer coating of a layer made of a material having a high refractive index and a layer made of a material having a low refractive index is formed on the surface of a supporting substrate such as a film. So-called multi-coating is known (see Patent Document 3).

  However, in order to form such a multilayer coating, after applying and curing an antireflection coating composition containing a compound capable of providing a cured coating having a high refractive index on the surface of a supporting substrate such as a film, After applying an antireflective coating forming composition containing a compound capable of giving a cured coating having a low refractive index, it is necessary to cure, requiring two coatings and curing, making the manufacturing process complicated. .

In addition, since these antireflection films are located on the outermost surface of the display surface, fingerprints and dust are likely to adhere to the display surface, and when they are wiped off using an alkaline household detergent, etc. There were problems such as scratches on the film (abrasion resistance) and damage to the film by alkali.
As described above, it is desired to achieve both simplification of the manufacturing process and scratch resistance, and further improvement of alkali resistance.
Japanese Unexamined Patent Publication No. 6-0667019 JP-A-6-136062 JP-A-7-005452

  The objective of this invention is providing the manufacturing method of the antireflection film excellent in productivity, and provides the manufacturing method of the antireflection film which has the outstanding antireflection property, without performing a complicated process. It is a further object of the present invention to provide a method for producing an antireflection film having excellent surface scratch resistance.

In order to solve the above-mentioned problems, the present inventors have intensively studied and, as a result, completed the following invention. That is, the present invention is as follows.
(1) A method for producing an antireflection film having two layers having different refractive indexes on at least one surface of a supporting substrate,
A step of applying and drying and curing the coating composition once on at least one surface of the supporting substrate,
The coating composition contains two or more kinds of inorganic particles,
At least one kind of inorganic particles in the two or more kinds of inorganic particles are inorganic particles whose surface is treated with a fluorine compound,
Furthermore, the manufacturing method of the antireflection film characterized by including an alkylphenone derivative.
(2) The method for producing an antireflection film as described in (1) above, wherein the alkylphenone derivative is a hydroxyalkylphenone derivative.
(3) The inorganic particles surface-treated with the fluorine compound are particles obtained by surface-treating silica particles with a fluorine compound (hereinafter, silica particles surface-treated with a fluorine compound are referred to as fluorine-treated silica particles),
The other inorganic particles excluding the fluorinated silica particles are inorganic particles having a refractive index higher than that of the silica particles, and the method for producing an antireflection film according to (1) or (2) .
(4) The surface treatment for obtaining the fluorine-treated silica particles is characterized in that the silica particles are treated with a compound represented by the following general formula (I) and further treated with a compound represented by the general formula (II). The manufacturing method of the antireflection film as described in (3).
_{^{A-R 1 -SiR 2 n (}} OR 3) 3-n Formula (I)
B—R ⁴ —Rf Formula (II)
(A and B in the above general formula represent a reactive double bond group, R ¹ and R ⁴ represent an alkylene group having 1 to 3 carbon atoms and an ester structure derived therefrom, and R ² and R ³ represent Hydrogen or an alkyl group having 1 to 4 carbon atoms, Rf represents a fluoroalkyl group, n represents 0, 1 or 2 and each may have a side chain in the structure.
(5) The silica particles are silica particles having cavities therein and / or silica particles having pores,
The method for producing an antireflection film according to (3) or (4), wherein the number average particle diameter of the silica particles is from 1 nm to 200 nm.
(6) The inorganic particles having a higher refractive index than the silica particles are made of a metal oxide having a number average particle diameter of 1 nm to 150 nm and a refractive index of 1.60 to 2.80, The manufacturing method of the antireflection film in any one of 3) to (5).
(7) The method for producing an antireflection film as described in (6), wherein the metal oxide is indium-containing tin oxide (ITO) and / or antimony-containing tin oxide (ATO).
(8) An antireflection film obtainable by the production method according to any one of (1) to (7).
(9) An image display device provided with the antireflection film according to (8).
(10) A coating composition containing two or more kinds of inorganic particles and an alkylphenone derivative,
The coating composition, wherein the two or more kinds of inorganic particles include silica particles (fluorinated silica particles) surface-treated with a fluorine compound, and a metal oxide.
(11) The surface treatment for obtaining the fluorine-treated silica particles is characterized in that the silica particles are treated with a compound represented by the following general formula (I) and further treated with a compound represented by the general formula (II). The coating composition according to (10) above.
_{^{A-R 1 -SiR 2 n (}} OR 3) 3-n Formula (I)
B—R ⁴ —Rf Formula (II)
(A and B in the above general formula represent a reactive double bond group, R ¹ and R ⁴ represent an alkylene group having 1 to 3 carbon atoms and an ester structure derived therefrom, and R ² and R ³ represent Hydrogen or an alkyl group having 1 to 4 carbon atoms, Rf represents a fluoroalkyl group, n represents 0, 1 or 2 and each may have a side chain in the structure.

  According to the present invention, it is possible to form a two-layer structure having different refractive indexes by only applying and drying and curing a specific one-component coating composition on at least one side of a supporting base material, so that good antireflection is achieved. Since an antireflection film exhibiting performance can be formed and the manufacturing process of the antireflection film can be simplified, productivity can be improved. Further, according to the production method of the present invention, an antireflection film having good scratch resistance can be provided. Furthermore, by laminating on a support substrate having a functional multilayer structure such as a hard coat layer, an image display device having excellent productivity can be provided.

  Hereinafter, embodiments of the present invention will be described in detail.

  The present invention relates to a method for producing an antireflection film having two layers having different refractive indexes on at least one side of a supporting substrate, wherein one coating composition is applied and dried and cured once on at least one side of the supporting substrate. The coating composition contains two or more types of inorganic particles, and at least one type of inorganic particles in the two or more types of inorganic particles is surface-treated with a fluorine compound. Inorganic particles and further contains an alkylphenone derivative.

  The antireflection film obtained by such a production method of the present invention can form two layers having different refractive indexes on a supporting substrate by a single coating / drying curing process. A laminated structure of a high refractive index layer / low refractive index layer is obtained. Compared with the manufacturing method of the normal anti-reflective film which requires processes, such as application | coating drying hardening of a high refractive index layer, and application | coating drying hardening of a low refractive index layer, the manufacturing method of this invention can reduce cost significantly.

  Moreover, this invention contains the coating composition suitable for the antireflection film which can be obtained with the said manufacturing method, the image display apparatus provided with this antireflection film, and the said manufacturing method.

[Antireflection film]
The antireflection film agrees with the antireflection film, and its necessity and required performance are preferably 0.03 or more, more preferably 0.00, as described in JP-A-59-50401. This is an aspect constituted by laminating two layers having a refractive index difference of 05 or more on a supporting substrate. Moreover, it is preferable that the refractive index difference of two layers on a support base material is 5.0 or less. In the antireflection film, it is more preferable that the most distant layer measured from the support substrate is a low refractive index layer. That is, it is preferable that the support base, the high refractive index layer, and the low refractive index layer are laminated in this order. In addition, although it mentions later about a support base material, if the laminated body of a hard-coat layer and a film is applied as a support base material, it will be a hard-coat layer between the film and high refractive index layer which are some support base materials. Similarly, it is also possible to provide another layer between the film and the high refractive index layer by using a laminate of a layer having a different function and a film as the supporting base material. The refractive index difference is a value obtained by relatively comparing the refractive indexes of adjacent layers. A layer having a relatively low refractive index is called a low refractive index layer, and a layer having a relatively high refractive index is a high refractive index layer. Call it. Japanese Patent Application Laid-Open No. 59-50401 also describes a method of providing a middle refractive index layer in a laminated film to supplement the antireflection performance.

  According to the method for producing an antireflection film of the present invention, a step of applying, drying, and curing once a one-component coating composition containing two or more kinds of specific inorganic particles and an alkylphenone derivative to at least one surface of a supporting substrate. Thus, an antireflection film having two layers having different refractive indexes can be produced.

  More specifically, one liquid containing two or more types of inorganic particles, wherein at least one type of inorganic particles in the two or more types of inorganic particles is an inorganic particle whose surface is treated with a fluorine compound, and further containing an alkylphenone derivative. By the process of applying and drying and curing the coating composition once, an antireflection film in which a high refractive index layer is formed on a supporting substrate and a low refractive index layer is formed on the high refractive index layer can be produced.

  In the present invention, the principle of constituting the two layers from the coating composition is considered to form a phase separation structure using the surface free energy difference of two or more kinds of inorganic particles as a driving force. Inorganic particles surface-treated with a fluorine compound have a low surface free energy, so they are considered to easily move to the air side (ie, the outermost surface layer), and to the upper layer side (air side, ie, the outermost surface layer) as the specific gravity decreases It is considered easy to move.

  The two layers having different refractive indexes in the present invention are measured by a reflectance spectral film thickness meter in the range of 300 to 800 nm, and the refractive index obtained using the software [FE-Analysis] attached to the device is Refers to two different layers.

Specifically, the reflectance is measured in the range of 300 to 800 nm using a reflection spectral film thickness meter (FE-3000, manufactured by Otsuka Electronics Co., Ltd.), and the film thickness measuring device general catalog P6 (manufactured by Otsuka Electronics Co., Ltd. Non-linear least square method)], the optical constants (C ₁ , C ₂ , The refractive index can be measured by calculating C ₃ ). In addition, the value in 550 nm was used for the refractive index.

Here, λ represents a wavelength, and C ₁ , C ₂ , and C ₃ represent optical constants.

  Examples of the measuring device capable of measuring the refractive index of each layer include a reflection spectral film thickness meter (FE-3000, manufactured by Otsuka Electronics Co., Ltd.), a high-precision refractive index measuring device (manufactured by Film Tec Scientific Computing International), and the like. Not as long.

  In addition, it is preferable that the antireflection film obtained by such a production method of the present invention has a clear interface between the high refractive index layer and the low refractive index layer which are two layers having different refractive indexes.

  A clear interface in the present invention refers to a state in which one layer can be distinguished from another layer. The distinguishable interface represents an interface that can be determined by observing a cross section using a transmission electron microscope (TEM), and can be determined according to the following method.

  An image taken by a TEM at a magnification of 200,000 times is pasted on presentation software (Microsoft Power Point 2003) using a scanner. Next, image control processing (contrast is set to 90%) of the pasted photograph is performed to enhance the contrast. At this time, when a clear boundary can be drawn at the interface between one layer and another layer, it is considered that there is a clear interface.

In order to exhibit good performance as an antireflection film, the minimum reflectance is preferably 0% or more and 1.0% or less, more preferably 0% or more and 0.7% or less, and further preferably 0% or more in spectroscopic measurement. It is 0.6% or less, and particularly preferably 0% or more and 0.5% or less.
In order to exhibit good performance as an antireflection film, the delta reflectance in the spectroscopic measurement is preferably 0% or more and 2.5% or less, more preferably 0% or more and 2.0% or less, and still more preferably It is desirable that it is 0% or more and 1.8% or less. The delta reflectance indicates a value obtained by subtracting the minimum reflectance from the maximum reflectance in a wavelength region of 400 nm to 800 nm when the light reflection spectrum is measured. When comparing the antireflection performance of the film, the delta reflectance is one index, and it can be said that the smaller the value of the delta reflectance, the better. When the delta reflectance is increased, the reflection at a specific region wavelength in the reflected light beam is relatively increased, and as a result, the reflected light beam is unfavorable.

Moreover, in order to show a favorable property as an antireflection film, it is further desirable that the transparency is high. If the transparency is low, it is not preferable when used as an image display device because image quality is deteriorated due to a decrease in image saturation. A haze value can be used for evaluating the transparency of the antireflection film obtained by the production method of the present invention. Haze is an index of turbidity of a transparent material defined in JIS K 7136 (2000). The smaller the haze, the higher the transparency. The haze value of the antireflection film is preferably 3.0% or less, more preferably less than 2.0%, still more preferably less than 1.0%, and the smaller the value, the better the transparency. However, it is difficult to set it to 0%, and a realistic lower limit value is considered to be about 0.01%. If the haze value is 3.0% or more, there is a high possibility that image degradation will occur.
[Inorganic particles]
The coating composition used in the production method of the present invention contains two or more types of inorganic particles. The number of types of inorganic particles is preferably 2 or more and 20 or less, more preferably 2 or more and 10 or less, and still more preferably. Is 2 or more and 3 or less. Here, the type is determined by the type of metal element constituting the inorganic particles. That is, in the case of inorganic particles made of the same metal element, for example, Zn, even if there are a plurality of Zn particles having different particle sizes, these are the same inorganic particles.

  The type of inorganic particles is not particularly limited as long as the coating composition containing the inorganic particles is formed by coating and drying and curing once on at least one surface of the supporting substrate, and two layers having different refractive indexes are formed. Atomic Na, K, Mg, Ca, Ba, Al, Zn, Fe, Cu, Ti, Sn, In, W, Y, Zr, Sb, Mn, Ga, V, Nb, Ta, Ag, Si, B, Bi , Mo, Ce, Cd, Be, Pb, Eu, and the like, and inorganic particles containing at least one metal atom. Moreover, the metal contained in the inorganic particles may be plural, and inorganic particles containing one or more and five or less metals may be used.

In addition, at least one of the two or more types of inorganic particles is inorganic particles surface-treated with a fluorine compound (inorganic particles surface-treated with a fluorine compound are hereinafter referred to as fluorine-treated inorganic particles) (refracted on the supporting substrate) Inorganic particles that are preferably used as a low refractive index layer component of an antireflection film having two layers with different ratios), but suitable inorganic particles for the fluorinated inorganic particles include Si, Na, K, Ca, And inorganic particles containing an element selected from Mg and Mg, and more preferably, silica particles (SiO ₂ ), alkali metal fluorides (NaF, KF, etc.), and alkaline earth metal fluorides (CaF ₂ , MgF) ₂ ) and the like, and silica particles are particularly preferable from the viewpoint of durability, refractive index and the like. The silica particles surface-treated with a fluorine compound are hereinafter referred to as fluorine-treated silica particles.

The silica particles preferably used as the inorganic particles (inorganic particles of the low refractive index layer constituting component) of the fluorinated inorganic particles include a composition composed of either a silicon compound or a polymerized (condensed) compound of an organic silicon compound. As a general example, it is a general term for particles derived from silicon compounds such as SiO ₂ .

Silica particles that are preferably used as inorganic particles (inorganic particles of low refractive index layer constituents), which are constituent materials of fluorine-treated inorganic particles, are compositions composed of either a silicon compound or a polymerized (condensed) product of an organic silicon compound. As a general example, it is a general term for particles derived from silicon compounds such as SiO ₂ .

  The shape of the inorganic particles (inorganic particles such as silica particles constituting the low refractive index layer), which is a constituent material of the fluorine-treated inorganic particles, is not particularly limited, but is formed after lamination. From the viewpoint of the refractive index of the layer to be formed, a spherical shape is preferable, and it is more preferable that a hollow and / or porous structure is formed in the silica particle (a silica particle having a cavity inside the particle and / or a particle). Silica particles having pores on the surface and inside are preferred.) If the inorganic particles such as silica particles have a polyhedral structure, there is a possibility that the particles are laminated without gaps in the layer, and the transparency required for the image display device cannot be obtained. Also, the effect of lowering the density of the layer by using inorganic particles such as silica particles having hollow and / or porous (having voids inside the particles and / or having pores on the surface and inside of the particles) Is obtained. In particular, it is possible to use silica particles having voids inside and / or silica particles having pores on the surface and inside as inorganic particles that are constituent materials of fluorine-treated inorganic particles. It is preferable because it is easily contained in the low refractive index layer of the antireflection film obtained by the method and the low refractive index layer is suitably formed. Silica particles having hollow and / or porous properties (having cavities inside and / or having pores on the surface and inside) are hereinafter referred to as hollow particles.

  Next, the number average particle diameter of inorganic particles that are constituent materials of fluorinated inorganic particles suitable for the low refractive index layer will be described. The number average particle diameter (number average particle diameter before surface treatment) of inorganic particles such as hollow silica suitable for inorganic particles constituting the low refractive index layer and constituting the fluorinated inorganic particles is smaller than 1 nm. This is not preferable because the refractive index increases and the transparency may decrease due to the decrease in the void density in the layer, and the number average particle diameter of inorganic particles such as hollow silica (number average particle diameter before surface treatment) ) Larger than 200 nm is not preferable because the thickness of the low refractive index layer is increased and good antireflection performance cannot be obtained, and is thus surface-treated with the fluorine compound in the coating composition used in the production method of the present invention. The inorganic particles such as hollow silica particles have a number average particle size (number average particle size before surface treatment) of preferably 1 nm to 200 nm, more preferably 5 nm to 180 nm. More preferably from 100nm from 5 nm.

  The number average particle diameter in the present invention refers to the particle diameter determined by a transmission electron microscope. The magnification was 500,000 times, the outer diameters of 10 particles present on the screen were measured, and the average value was obtained.

  Here, the outer diameter means the maximum diameter of the particle (that is, the longest diameter of the particle and indicates the longest diameter in the particle). Similarly, in the case of a particle having a cavity inside, the maximum diameter of the particle is also defined. To express.

  Since the fluorinated inorganic particles can be preferably moved to the air side (outermost surface layer) to form a low refractive index layer, at least one of the two or more types of inorganic particles used in the coating composition. It is important that the inorganic particles are surface-treated with a fluorine compound. In addition, rather than all the inorganic particles of two or more types of inorganic particles being fluorine-treated inorganic particles, it is better to use a coating composition containing both fluorine-treated inorganic particles and inorganic particles that have not been surface-treated. Two layers having a large difference in refractive index can be obtained, which is preferable in terms of antireflection properties.

  The inorganic particles that have been surface-treated with a fluorine compound are silica particles such as hollow silica particles, that is, the fluorine-treated inorganic particles are particularly preferably fluorine-treated silica particles.

  The surface treatment step with a fluorine compound for inorganic particles such as hollow silica may be performed in one step or may be performed in multiple steps. Further, a compound containing fluorine may be used in a plurality of stages, or a compound containing fluorine may be used only in one stage.

  Moreover, the fluorine compound preferably used in the surface treatment process of inorganic particles such as hollow silica may be a single compound or a plurality of different compounds.

  Surface treatment with a fluorine compound refers to a step of chemically modifying inorganic particles such as hollow silica particles and introducing a fluorine-containing compound into inorganic particles such as hollow silica particles.

  As a method of directly introducing a fluorine compound into inorganic particles such as hollow silica particles, fluoroalkoxysilane having both a fluorine segment and a silyl ether group (including a silanol group obtained by hydrolyzing a silyl ether group) in one molecule There is a method in which at least one compound and an initiator are stirred together. However, when a fluorine compound is directly introduced into inorganic particles such as hollow silica particles, it may be difficult to control the reactivity, or coating spots may be easily generated during coating after coating.

  As a further method of chemically modifying inorganic particles such as hollow silica particles and introducing a fluorine-containing compound into inorganic particles such as hollow silica particles, inorganic particles such as hollow silica particles are treated with a crosslinking component. There is a method of joining with a fluorine compound having a functional group.

  As a crosslinking component, there is no fluorine in the molecule, but a compound having at least one site capable of reacting with a fluorine compound and at least one site capable of reacting with inorganic particles such as hollow silica particles in one molecule, The site capable of reacting with inorganic particles such as hollow silica particles is preferably silyl ether or a hydrolyzate of silyl ether from the viewpoint of reactivity. These compounds are generally called silane coupling agents. For example, glycidoxyalkoxysilanes, aminoalkoxysilanes, acryloylsilanes, methacryloylsilanes, vinylsilanes, mercaptosilanes, etc. may be used. it can.

  As the fluorine compound having a functional group, fluoroalkyl alcohol, fluoroalkyl epoxide, fluoroalkyl halide, fluoroalkyl acrylate, fluoroalkyl methacrylate, fluoroalkyl carboxylate (including acid anhydrides and esters), etc. may be used. it can.

A more preferable form of surface treatment for obtaining the fluorinated inorganic particles in the present invention is that silica particles (particularly hollow silica particles) are treated with a compound represented by the following general formula (I), and further represented by the following general formula (II): It is preferred to treat with the indicated compound.
_{^{A-R 1 -SiR 2 n (}} OR 3) 3-n Formula (I)
B—R ⁴ —Rf Formula (II)
(A and B in the above general formula represent a reactive double bond group, R ¹ and R ⁴ represent an alkylene group having 1 to 3 carbon atoms and an ester structure derived therefrom, and R ² and R ³ represent Hydrogen or an alkyl group having 1 to 4 carbon atoms, Rf represents a fluoroalkyl group, n represents 0, 1 or 2 and each may have a side chain in the structure.
The reactive double bond group in the present invention is a functional group that chemically reacts with radicals generated by receiving energy such as light or heat, and specific examples include vinyl group, allyl group, acryloyl group, methacryloyl group. Etc.

  Specific examples of the general formula (I) include acryloxyethyltrimethoxysilane, acryloxypropyltrimethoxysilane, acryloxybutyltrimethoxysilane, acryloxypentyltrimethoxysilane, acryloxyhexyltrimethoxysilane, acryloxyheptyltri Methoxysilane, methacryloxyethyltrimethoxysilane, methacryloxypropyltrimethoxysilane, methacryloxybutyltrimethoxysilane, methacryloxyhexyltrimethoxysilane, methacryloxyheptyltrimethoxysilane, methacryloxypropylmethyldimethoxysilane, methacryloxypropylmethyldimethoxy Examples include silane and compounds in which the methoxy group in these compounds is substituted with other alkoxyl groups and hydroxyl groups.

  Specific examples of the general formula (II) include 2,2,2-trifluoroethyl acrylate, 2,2,3,3,3-pentafluoropropyl acrylate, 2-perfluorobutylethyl acrylate, 3-perfluoro Butyl-2-hydroxypropyl acrylate, 2-perfluorohexylethyl acrylate, 3-perfluorohexyl-2-hydroxypropyl acrylate, 2-perfluorooctylethyl acrylate, 3-perfluorooctyl-2-hydroxypropyl acrylate, 2- Perfluorodecylethyl acrylate, 2-perfluoro-3-methylbutylethyl acrylate, 3-perfluoro-3-methoxybutyl-2-hydroxypropyl acrylate, 2-perfluoro-5-methylhexylethyl acrylate 3-perfluoro-5-methylhexyl-2-hydroxypropyl acrylate, 2-perfluoro-7-methyloctyl-2-hydroxypropyl acrylate, tetrafluoropropyl acrylate, octafluoropentyl acrylate, dodecafluoroheptyl acrylate, Hexadecafluorononyl acrylate, hexafluorobutyl acrylate, 2,2,2-trifluoroethyl methacrylate, 2,2,3,3,3-pentafluoropropyl methacrylate, 2-perfluorobutylethyl methacrylate, 3-perfluorobutyl 2-hydroxypropyl methacrylate, 2-perfluorooctylethyl methacrylate, 3-perfluorooctyl-2-hydroxypropyl methacrylate, 2-perful Rhodecylethyl methacrylate, 2-perfluoro-3-methylbutylethyl methacrylate, 3-perfluoro-3-methylbutyl-2-hydroxypropyl methacrylate, 2-perfluoro-5-methylhexylethyl methacrylate, 3-perfluoro-5 -Methylhexyl-2-hydroxypropyl methacrylate, 2-perfluoro-7-methyloctylethyl methacrylate, 3-perfluoro-7-methyloctylethyl methacrylate, tetrafluoropropyl methacrylate, octafluoropentyl methacrylate, octafluoropentyl methacrylate, dodeca Fluoroheptyl methacrylate, hexadecafluorononyl methacrylate, 1-trifluoromethyltrifluoroethyl methacrylate, hexa Such as Le Oro butyl methacrylate.

  By using the compound represented by the general formula (I) having no fluorine segment in the molecule, it becomes possible not only to modify the surface of silica particles such as hollow silica under simple reaction conditions, but also silica particles. It is possible to introduce a functional group whose reactivity is easy to control on the surface, and as a result, it is possible to react a fluorine segment having a reactive double bond on the surface of the silica particles.

  The low refractive index layer is one of the two layers having different refractive indexes laminated on the support substrate, and is adjacent to one layer (antireflection film constituting layer excluding the air layer). It is a layer having a low relative refractive index. As described above, the antireflection film obtained by the production method of the present invention preferably has a support base, a high refractive index layer, and a low refractive index layer formed in this order. As a method for reducing the refractive index, a method using a fluorine-based polymer (Japanese Patent Laid-Open No. 2002-36457) and a method of reducing the density (Japanese Patent Laid-Open No. 8-83581) are known. Therefore, it is important that the coating composition contains fluorine-treated inorganic particles. It is because these particles can form a low refractive index layer suitably by including inorganic particles surface-treated with a fluorine compound in the coating composition. Here, the silica particles and the compounds represented by the general formula (I) and the general formula (II) described above remain unreacted in the coating composition used in the present invention and the compounds of the general formula (I). And the general formula (II) compound may be present, or the silica particles may be surface-treated with the general formula (I) compound and the general formula (II) compound to exist as a condensate and / or a polymer. .

  Next, the high refractive index layer will be described.

  The high refractive index layer is one of the layers laminated on the supporting substrate, refers to a layer having a higher refractive index than the adjacent layer, and at least one kind of inorganic particles such as a metal oxide It is preferable to contain.

The inorganic particles used as the high refractive index layer component in the coating composition are not particularly limited, but inorganic particles that are not surface-treated with a fluorine compound (inorganic particles other than fluorine-treated inorganic particles) are preferred, and the low refractive index layer configuration It is preferably an inorganic particle different from the inorganic particle used as a component (an inorganic particle that is a constituent material of the fluorinated inorganic particle), and is selected from the group consisting of Zr, Ti, Al, In, Zn, Sb, Sn, and Ce. More preferably, it is an oxide particle of at least one selected metal. The inorganic particles used as the high refractive index layer component are preferably inorganic particles having a higher refractive index than silica particles. Specifically, zirconium oxide (ZrO ₂ ), titanium oxide (TiO ₂ ), aluminum oxide (Al ₂ O ₃ ), indium oxide (In ₂ O ₃ ), zinc oxide (ZnO), tin oxide (SnO 2), antimony oxide (Sb ₂ O ₃ ), and indium tin oxide (In ₂ O ₃ ) One metal oxide, particularly preferably indium-containing tin oxide (ITO) or antimony-containing tin oxide (ATO) derived from Sb or Sn.

  Number average particle diameter of inorganic particles suitable as high refractive index layer constituents in coating compositions, especially average particles of inorganic particles composed of metal oxides having a higher refractive index than silica particles suitable as low refractive index layer constituents The diameter is preferably 1 nm to 150 nm, more preferably 5 nm to 100 nm. If the number average particle diameter of the inorganic particles is smaller than 1 nm, it is not preferable because the transparency decreases due to a decrease in the void density in the layer. If the number average particle diameter of the inorganic particles is larger than 150 nm, the high refractive index layer is not preferable. This is not preferable because the thickness increases and it is difficult to obtain good antireflection performance.

  The refractive index of the inorganic particles suitable as a high refractive index layer constituent in the coating composition, particularly the refractive index of the inorganic particles made of a metal oxide having a higher refractive index than silica particles suitable as the low refractive index layer constituent , Preferably 1.58 to 2.80, more preferably 1.60 to 2.50. If the refractive index of the inorganic particles is smaller than 1.58, the refractive index of the high refractive index layer may be lowered, and if the refractive index of the inorganic particles is larger than 2.80, the refractive index difference of the high refractive index layer. May increase, and good antireflection performance may not be obtained.

  As described above for the inorganic particles used as the high refractive index layer component in the coating composition, when the inorganic particles subjected to the surface treatment with the fluorine compound are silica particles, the inorganic particles have a higher refractive index than the silica particles. The inorganic particles having a refractive index higher than that of the silica particles are particularly preferably metal oxides having a number average particle diameter of 1 nm to 150 nm and a refractive index of 1.60 to 2.80. The product is preferably used. Specific examples of such metal oxides include indium-containing tin oxide (ITO) and / or antimony-containing tin oxide (ATO).

  In the coating composition used in the production method of the present invention, when the inorganic particles surface-treated with the fluorine compound are silica particles and the other inorganic particles are inorganic particles having a higher refractive index than the silica particles, The coating composition is applied and dried and cured on at least one surface of the material to support the low refractive index layer containing the silica particles and the high refractive index layer containing inorganic particles having a higher refractive index than the silica particles. Since a base material, a high refractive index layer, and a low refractive index layer can be suitably formed in this order, it is a preferable aspect.

  The coating composition used in the present invention can further contain a binder component. That is, the low refractive index layer and the high refractive index layer of the antireflection film of the present invention may contain a binder component separately from the above-described substances. Although it does not specifically limit as a binder component, From a viewpoint of manufacturability, it is preferable that it is a binder (resin) which can be hardened | cured with a heat | fever and / or active energy ray, etc., and binder (resin) is one type. Alternatively, two or more kinds may be mixed and used. In addition, from the viewpoint of retaining the inorganic particles surface-treated with the fluorine compound that is the low refractive index layer constituent in the present invention and the other inorganic particles that are the high refractive index layer constituent in the film, It is preferable that the binder component has an alkoxysilane, a hydrolyzate of alkoxysilane, or a reactive double bond. In the case of curing with UV rays, it is preferable that the oxygen concentration is as low as possible because oxygen inhibition can be prevented more than in an oxygen atmosphere, and it is more preferable to cure in a nitrogen atmosphere (nitrogen purge). When the oxygen concentration is high, the curing of the outermost surface is inhibited, the curing becomes insufficient, and the scratch resistance and alkali resistance may be insufficient.

[Alkylphenone derivatives]
The coating composition used in the present invention includes inorganic particles surface-treated with the above-described fluorine compound which is a low refractive index component, other inorganic particles which are the above high refractive index component, and an alkylphenone derivative. .

The alkylphenone derivative used in the present invention is a compound represented by the general formula (III) and a substance derived therefrom. In the antireflection film, it may be added as a radical generator to the polymer terminal. .
_{C 6 H 5 -C (O)} -R 5 Formula (III)
(R ⁵ in the above general formula is quaternary carbon and may be cyclic)
Specific examples of the alkylphenone derivative include 2.2-dimethoxy-1.2-diphenylethane-1-one, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, 2 -Benzyl-2-dimethylamino-1- (4-phenyl) -1-butane, 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- (4-phenyl) -1-butane 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -1-butane, 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4 -Morpholinyl) phenyl] -1-butane, 1-cyclohexyl-phenyl ketone, 2-methyl-1-phenylpropan-1-one, 1- [4- (2-ethoxy) -phenyl] -2-hydroxy-2- Methyl 1-1-one, and the like.

In order to obtain better surface scratch resistance in the present invention, it is preferable to use a hydroxyalkylphenone derivative having an alkyl compound at the R ⁵ site and having a hydroxyl group at the terminal. Specific examples of the hydroxyalkylphenone derivative include 1-hydroxycyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- [4- (2-hydroxyethoxy) phenyl]- 2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propane -1-one and the like can be mentioned.

  The coating composition used in the present invention includes inorganic particles (fluorine-treated inorganic particles) surface-treated with a fluorine compound suitable as the above-described low refractive index layer constituents, and other high refractive index layer constituents described above. It is desirable to include inorganic particles, the aforementioned alkylphenone derivative, and a solvent. As long as the coating composition is in a state where the coating composition can be applied, the required amount and properties are not limited. Therefore, a solvent generally used as a coating solvent can be used although it is not particularly described.

  The coating composition used in the present invention preferably further contains an initiator, a curing agent and a catalyst. The initiator and the catalyst are used to promote the reaction between the hollow silica, which is inorganic particles surface-treated with the fluorine compound, and the binder (resin), or to promote the reaction between the binder (resin). As the initiator, those capable of initiating or accelerating polymerization and / or condensation and / or crosslinking reaction by anion, cation, radical reaction or the like of the coating composition are preferable.

  Known or well-known initiators and curing agents and catalysts can be used. A plurality of initiators may be used at the same time or may be used alone. Furthermore, you may use together an acidic catalyst, a thermal-polymerization initiator, and a photoinitiator. Examples of acidic catalysts include aqueous hydrochloric acid, formic acid, acetic acid and the like. Examples of the thermal polymerization initiator include peroxides and azo compounds. Examples of photopolymerization initiators include, but are not limited to, aryl ketone compounds, sulfur-containing compounds, acyl phosphine oxide compounds, and amine compounds. The addition ratio of the initiator and the curing agent is preferably 0.001 to 30 parts by weight, more preferably 0.05 to 20 parts by weight with respect to 100 parts by weight of the resin component in the coating composition. Parts, more preferably 0.1 to 10 parts by weight.

  In addition, additives such as various silane coupling agents, surfactants, thickeners, and leveling agents may be appropriately added to the coating composition used in the present invention as necessary.

[Other layers]
The antireflection film obtained by the production method of the present invention may further be provided with a hard coat layer, a moisture proof layer, an antistatic layer, an undercoat layer, a protective layer and the like.

The hard coat layer is provided for imparting scratch resistance to the film which is a part of the supporting substrate. The hard coat layer also has a function of strengthening the adhesion between the support substrate and the layer thereon. The hard coat layer can be formed using an acrylic polymer, a urethane polymer, an epoxy polymer, a silicon polymer, or a silica compound. A pigment may be added to the hard coat layer. The acrylic polymer is preferably synthesized by a polymerization reaction of a polyfunctional acrylate monomer (eg, polyol acrylate, polyester acrylate, urethane acrylate, epoxy acrylate). Examples of the urethane polymer include melamine polyurethane. As the silicon-based polymer, a cohydrolyzate of a silane compound (eg, tetraalkoxysilane, alkyltrialkoxysilane) and a silane coupling agent having a reactive group (eg, epoxy, methacryl) is preferably used. Further, two or more kinds of polymers may be used in combination. As the silica compound, colloidal silica is preferably used. The strength of the hard coat layer is preferably a pencil hardness of 1 kg load, preferably H or higher, more preferably 2H or higher, and most preferably 3H or higher. In addition to the hard coat layer, the support substrate may be provided with an adhesive layer, a shield layer, and a sliding layer. The shield layer is provided to shield electromagnetic waves and infrared rays.
[Supporting substrate]
It is important that the antireflective film has a supporting substrate, except when the antireflective film is directly provided on the CRT image display surface or lens surface. As the supporting substrate, a plastic film is more preferable than a glass plate. Examples of plastic film materials include cellulose esters (eg, triacetyl cellulose, diacetyl cellulose, propionyl cellulose, butyryl cellulose, acetyl propionyl cellulose, nitrocellulose), polyamides, polycarbonates, polyesters (eg, polyethylene terephthalate, polyethylene naphthalate). , Poly-1,4-cyclohexanedimethylene terephthalate, polyethylene-1,2-diphenoxyethane-4,4′-dicarboxylate, polybutylene terephthalate), polystyrene (eg, syndiotactic polystyrene), polyolefin (eg, Polypropylene, polyethylene, polymethylpentene), polysulfone, polyethersulfone, polyarylate, polyetherimide, polymethylmethene Tacrylate and polyetherketone are included, but among these, triacetyl cellulose, polycarbonate, polyethylene terephthalate and polyethylene naphthalate are particularly preferable. Moreover, as above-mentioned, a support base material can also be made into the film which has various functional layers, such as a hard-coat layer, an adhesive layer, a shield layer, and a sliding layer.

  The light transmittance of the supporting substrate is preferably 80% or more and 100% or less, and more preferably 86% or more and 100% or less. Here, the light transmittance is a ratio of light transmitted through the sample when irradiated with light, and is an index of transparency of a transparent material that can be measured according to JIS K 7361-1 (1997). The larger the value of the light transmittance of the antireflection film, the better. The smaller the value, the higher the haze value and the higher the possibility of image deterioration. Haze is an index of turbidity of a transparent material defined in JIS K 7136 (2000). The smaller the haze, the higher the transparency.

  The haze of the support substrate is preferably 0.01% or more and 2.0% or less, and more preferably 0.05% or more and 1.0% or less.

  The refractive index of the supporting substrate is preferably 1.4 to 1.7. The refractive index as used in the present invention is a ratio of changing the angle of the traveling direction at the interface when light travels from the air to a certain substance, and is a method defined in JIS K 7142 (1996). Can be measured.

An infrared absorber or an ultraviolet absorber may be added to the support substrate. The addition amount of the infrared absorber is preferably 0.01 to 20% by weight, more preferably 0.05 to 10% by weight, based on 100% by weight of all the components of the support base. As a slip agent, particles of an inert inorganic compound may be added to the transparent support. Examples of the inorganic _{compound, SiO 2, TiO 2, BaSO} 4, CaCO 3, talc and kaolin. Furthermore, the support substrate may be subjected to a surface treatment.

  Various surface treatments can be applied to the surface of the support substrate. Examples of the surface treatment include chemical treatment, mechanical treatment, corona discharge treatment, flame treatment, ultraviolet irradiation treatment, high frequency treatment, glow discharge treatment, active plasma treatment, laser treatment, mixed acid treatment and ozone oxidation treatment. Among these, glow discharge treatment, ultraviolet irradiation treatment, corona discharge treatment and flame treatment are preferred, and glow discharge treatment and ultraviolet treatment are more preferred.

[Coating, drying and curing]
In the production method of the present invention, a dip coating method, an air knife coating method, a curtain coating method, a roller coating method, a wire bar coating method, a gravure coating method, or the like is performed on at least one surface of a supporting substrate with a specific coating composition of one liquid. The antireflection film can be obtained by applying the coating method once (coating step) and subsequently drying the coating composition by heating or the like to cure the coating composition (drying step / curing step).

  According to the production method of the present invention, two layers having different refractive indexes can be formed simultaneously by the step of coating and drying and curing the one-component coating composition once. The formation of the two layers having different refractive indexes is carried out by applying a coating composition in which at least the composition for inducing the high refractive index layer of the present invention, the composition for inducing the low refractive index layer and a solvent are mixed, and then drying ( (Or drying and curing) step.

  In addition to completely removing the solvent from the antireflection film to be obtained, it is preferable to heat in the drying step from the viewpoint of separation into two layers without defects. The drying process is divided into (A) material preheating period, (B) constant rate drying period, and (C) reduced rate drying period. From the material preheating period (period in which the temperature is raised to the temperature at which the entire material is dried), the drying process is continued. Over the drying period (the period until the coating liquid stops moving), two layers with different refractive indexes are formed as the solvent evaporates. However, in order to ensure sufficient time for the movement of the inorganic particles forming the two layers, the wind speed Therefore, it is preferable to dry at as low a temperature as possible.

  The wind speed in the initial drying period (A) material preheating period and (B) constant rate drying period is preferably 1 m / s or more and 10 m / s or less, more preferably 1 m / s or more and 5 m / s or less. is there. In the decreasing rate drying period in the latter stage of drying, the wind speed is preferably 10 m / s or more and 70 m / s or less, and the temperature is preferably 100 ° C. or more and 200 ° C. or less from the viewpoint of reducing the residual solvent. The heating temperature can be determined from the boiling point of the solvent used and the glass transition temperature of the polymer, but is not particularly limited. Examples of the heating method in the drying process include a counter flow method, hot air injection, infrared rays, microwaves, induction heating, and the like. Among these, in (A) material preheating period and (B) constant rate drying period which are the initial stages of drying, the counter flow method is preferable from the viewpoint of wind speed and temperature, but is not particularly limited. In addition, in the (C) decreasing rate drying period which is the latter stage of drying, the tunnel type is preferable from the viewpoint of versatility.

  Furthermore, you may perform the further hardening operation (curing process) by irradiating a heat | fever or an energy ray with respect to the formation layer after a drying process. In the curing step, when cured with heat, the temperature is preferably from room temperature to 200 ° C., more preferably from 100 ° C. to 200 ° C. from the viewpoint of solvent evaporation and a curing aid for the resin containing silanol and the like. More preferably, it is 130 degreeC or more and 200 degrees C or less. Setting the temperature to 100 ° C. or higher is preferable because the amount of the remaining solvent is reduced and curing of the resin containing silanol proceeds in a very short time.

Moreover, when hardening with an energy ray, it is preferable that it is an electron beam (EB ray) and / or an ultraviolet-ray (UV ray) from a versatility point. In the case of curing with ultraviolet rays, the oxygen concentration is preferably as low as possible because oxygen inhibition can be prevented more than in an oxygen atmosphere, and curing in a nitrogen atmosphere (nitrogen purge) is more preferable. When the oxygen concentration is high, the curing of the outermost surface is inhibited, the curing becomes insufficient, and the scratch resistance and alkali resistance may be insufficient. Examples of the ultraviolet lamp used when irradiating ultraviolet rays include a discharge lamp method, a flash method, a laser method, and an electrodeless lamp method. When the discharge lamp type to ultraviolet cured using a high pressure mercury lamp is, illuminance 100~3000mW / cm ² of ultraviolet, ultraviolet irradiation under the conditions preferably 200~2000mW / cm ^2, further preferably a 300~1500mW / cm ² It is preferable to perform UV irradiation under the condition that the cumulative amount of ultraviolet light is 100 to 3000 m / cm ² , preferably 200 to 2000 mJ / cm ² , more preferably 300 to 1500 mJ / cm ² . Here, the ultraviolet illuminance is the irradiation intensity received per unit area, and changes depending on the lamp output, the emission spectral efficiency, the diameter of the light emitting bulb, the design of the reflector, and the light source distance to the irradiated object. However, the illuminance does not change depending on the conveyance speed. Further, the UV integrated light amount is irradiation energy received per unit area, and is the total amount of photons reaching the surface. The integrated light quantity is inversely proportional to the irradiation speed passing under the light source, and is proportional to the number of irradiations and the number of lamps.

When curing is performed by heat, the drying step and the curing step may be performed simultaneously. Moreover, the antireflection film obtained by the production method of the present invention can be provided on the viewing side surface of various image display devices such as PDP, thereby providing an image display device having excellent antireflection properties.
[Coating composition]
As described above, the coating composition used in the production method of the present invention includes two or more types of inorganic particles, and at least one of the inorganic particles is a fluorine-treated inorganic particle, and further includes an alkylphenone derivative. And And the alkylphenone derivative, the surface treatment method with the fluorine compound, and the inorganic particles that are preferably used in the coating composition are as described above. A more preferable embodiment of the coating composition is a coating composition containing two or more types of inorganic particles and an alkylphenone derivative, and the two or more types of inorganic particles include fluorinated silica particles and a metal oxide.

Furthermore, the surface treatment method for obtaining the fluorinated silica particles is a method in which the silica particles are treated with a compound represented by the following general formula (I) and further treated with a compound represented by the general formula (II). It is a particularly preferable embodiment.
_{^{A-R 1 -SiR 2 n (}} OR 3) 3-n Formula (I)
B—R ⁴ —Rf Formula (II)
(A and B in the above general formula represent a reactive double bond group, R ¹ and R ⁴ represent an alkylene group having 1 to 3 carbon atoms and an ester structure derived therefrom, and R ² and R ³ represent Hydrogen or an alkyl group having 1 to 4 carbon atoms, Rf represents a fluoroalkyl group, n represents 0, 1 or 2 and each may have a side chain in the structure.
The content of the coating composition of the present invention is not particularly limited as long as it includes two or more types of inorganic particles, at least one of which is a fluorine-treated inorganic particle, and further includes an alkylphenone derivative. However, preferably, in 100% by weight of the coating composition of the present invention, the total of two or more kinds of inorganic particles including fluorine-treated inorganic particles is 0.2% by weight to 40% by weight or less, and the alkylphenone derivative is 0.01 to 20% by weight, an embodiment containing 40 to 99% by weight of other components such as a solvent, a binder resin, the initiator, the curing agent and a catalyst, more preferably two or more types of inorganic particles containing fluorinated inorganic particles 1 to 35% by weight, alkylphenone derivative 0.05 to 15% by weight, and other components such as a solvent, a binder resin, the initiator, the curing agent, and a catalyst. .

  In a more preferred embodiment, the two or more kinds of inorganic particles are metal oxide particles and fluorinated silica particles, the total of these is 2 to 30% by weight, the alkylphenone derivative is 0.1 to 10% by weight, and other components Is an embodiment of 60 to 97% by weight.

  Further, in the total 100% by weight of the inorganic particles, the fluorine-treated inorganic particles are preferably 5 to 95% by weight, and the other inorganic particles are preferably 5 to 95% by weight, and the fluorine-treated inorganic particles are 10 to 90% by weight, More preferably, the other inorganic particles are 10 to 90% by weight.

  More preferably, in a total of 100% by weight of the inorganic particles, the fluorine-treated silica particles are 15 to 85% by weight and the metal oxide particles are 15 to 85% by weight. In addition, the ratio of the fluorinated silica particles to the metal oxide particles is 50 fluorinated silica particles in a total of 100% by weight of the inorganic particles from the viewpoint of the film thickness of the low refractive index layer and the high refractive index layer to be formed. It is an aspect of -85 weight% and a metal oxide particle 15 to 50 weight%.

  When the total of two or more kinds of inorganic particles including fluorine-treated inorganic particles is less than 0.2% by weight in 100% by weight of all the constituent components of the coating composition, a low refractive index layer, which is an antireflection layer, a high Since the thickness and refractive index of the refractive index layer are insufficient, good antireflection performance may not be obtained, and two or more kinds including fluorinated inorganic particles in 100% by weight of all components of the coating composition If the total of the inorganic particles exceeds 40% by weight, the film forming property and the adhesion with the high refractive index layer are lowered, or the distinguishable interface between the high refractive index layer and the low refractive index layer is lost. Problems may occur.

  As the fluorine-treated silica particles, it is preferable to use the hollow silica particles as described above because the low refractive index layer is suitably formed.

  The number average particle diameter (number average particle diameter before treatment) of such fluorinated silica particles is preferably 1 nm to 200 nm, more preferably 5 nm to 180 nm, from the viewpoint of transparency and antireflection properties as described above. More preferably, it is 5 nm to 100 nm.

  Since the fluorinated inorganic particles can be preferably moved to the air side (outermost surface layer) to form a low refractive index layer, at least one of the two or more types of inorganic particles used in the coating composition. It is important that the inorganic particles (especially silica particles) are surface-treated with a fluorine compound. In addition, all the inorganic particles of the two or more types of inorganic particles are treated with inorganic particles (particularly silica particles) subjected to a surface treatment with a fluorine compound, compared to when the surface treatment with a fluorine compound is performed. It is preferable to use a coating composition containing both inorganic particles (particularly metal oxides) from the viewpoint of antireflection properties because two layers having a large refractive index difference can be obtained.

In a preferred embodiment of the surface treatment of the inorganic particles with the fluorine compound in the present invention, silica particles (particularly hollow silica particles) are treated with a compound represented by the following general formula (I), and further a compound represented by the following general formula (II): This is processing as described above.
_{^{A-R 1 -SiR 2 n (}} OR 3) 3-n Formula (I)
B—R ⁴ —Rf Formula (II)
(A and B in the above general formula represent a reactive double bond group, R ¹ and R ⁴ represent an alkylene group having 1 to 3 carbon atoms and an ester structure derived therefrom, and R ² and R ³ represent Hydrogen or an alkyl group having 1 to 4 carbon atoms, Rf represents a fluoroalkyl group, n represents 0, 1 or 2 and each may have a side chain in the structure.
Specific examples of the general formula (I) include, as described above, acryloxyethyltrimethoxysilane, acryloxypropyltrimethoxysilane, and compounds in which the methoxy group in these compounds is substituted with other alkoxyl groups and hydroxyl groups. Is mentioned.

  Specific examples of the general formula (II) include 2,2,2-trifluoroethyl acrylate and 2,2,3,3,3-pentafluoropropyl acrylate as described above.

  By using the compound represented by the general formula (I) having no fluorine segment in the molecule, it becomes possible not only to modify the silica particle surface under simple reaction conditions, but also to make the silica particle surface reactive. It becomes possible to introduce a functional group that is easy to control, and as a result, a fluorine segment having a reactive double bond can be reacted on the surface of the silica particles.

Subsequently, the metal oxide that is one of the inorganic particles is zirconium oxide (ZrO ₂ ), titanium oxide (TiO ₂ ), aluminum oxide (Al ₂ O ₃ ), indium oxide (In ₂ O ₃ ), as described above. At least one metal oxide selected from the above is preferable, and indium-containing tin oxide (ITO) or antimony-containing tin oxide (ATO) derived from Sb, Sn, or the like is particularly preferable.

  The number average particle diameter of the metal oxide, particularly the average particle diameter of the metal oxide having a higher refractive index than the silica particles surface-treated with the fluorine compound, as described above, from the viewpoint of transparency and antireflection performance, It is 1 nm to 150 nm, more preferably 5 nm to 100 nm.

  The refractive index of the metal oxide, particularly the refractive index of the metal oxide having a higher refractive index than the fluorinated silica particles, is preferably 1.60 to 2.80, more preferably from the viewpoint of antireflection performance as described above. Is 1.60 to 2.50.

  In the coating composition used in the production method of the present invention, when the fluorinated inorganic particles are fluorinated silica particles and the other inorganic particles are metal oxides having a higher refractive index than the silica particles, 1 This is a preferred embodiment because a low refractive index layer containing fluorinated silica particles and a high refractive index layer containing metal oxide particles can be suitably formed by coating and drying the liquid coating composition once.

The alkylphenone derivative used in the production method of the present invention is a compound represented by the general formula (III) and a substance derived therefrom. In the antireflection film, it is added as a radical generator to the polymer terminal. May be.
_{C 6 H 5 -C (O)} -R 5 Formula (III)
(R ⁵ in the above general formula is quaternary carbon and may be cyclic)
These alkylphenone derivatives may be used alone or in combination of two or more. In order to obtain the stability of the coating material and good surface scratch resistance, it is preferable to use a hydroxyalkylphenone derivative in which R ⁵ is an alkyl compound in the above general formula (III) and has a hydroxyl group at its terminal. Specific examples of the hydroxyalkylphenone derivative include 1-hydroxycyclohexyl-phenyl-ketone and the like.

  As described above, the coating composition used in the present invention contains additives such as a binder component, a solvent, an initiator, a curing agent, a catalyst, various silane coupling agents, a surfactant, a thickener, and a leveling agent as necessary. May be added as appropriate. A plurality of binders can be used as the binder resin component in the coating composition, but a coating composition containing only one binder is more preferable from the viewpoint of compatibility.

  Next, although this invention is demonstrated based on an Example, this invention is not necessarily limited to these.

[Production example]
[Adjustment of high refractive index component (a)]
As a high refractive index component, antimony-containing tin oxide Opstar TU4005 (manufactured by JSR) was diluted with a methyl ethyl ketone: isopropanol mixed solution (mixing ratio = 1: 1) so as to have a solid content concentration of 6%.

[Adjustment of high refractive index component (b)]
Methyl isobutyl ketone was diluted by adding TYZ67-H01 (manufactured by Toyo Ink Co., Ltd.), which is zirconium oxide as a high refractive index component, so that the solid content concentration was 3.2% by weight.

[Adjustment of low refractive index component]
[Adjustment of low refractive index component (a)]
A hollow silica sulria TR-113 (manufactured by Catalytic Chemical Industry Co., Ltd .: 20 wt% solid content) was mixed with 4.4 g of methacryloxypropyltrimethoxysilane and 1.8 g of 5 wt% aqueous formic acid solution at 70 ° C. Stir for hours. Next, after adding 4.6 g of 2-perfluorooctylethyl acrylate and 0.2 g of 2,2-azobisisobutyronitrile, the mixture was heated and stirred at 70 ° C. for 30 minutes. Thereafter, 333 g of isopropyl alcohol was added and diluted to obtain a low refractive index component (a) having a solid content of 3.8% by weight.

[Adjustment of low refractive index component (b)]
A hollow silica sulria TR-113 (manufactured by Catalytic Chemical Industry Co., Ltd .: 20 wt% solid content) was mixed with 4.4 g of methacryloxypropyltrimethoxysilane and 1.8 g of 5 wt% aqueous formic acid solution at 70 ° C. Stir for hours. Thereafter, 221 g of isopropyl alcohol was added and diluted to obtain a low refractive index component (b) having a solid content of 3.6% by weight.

[Adjustment of low refractive index component (c)]
113 g of isopropyl alcohol was added to 20 g of through silica TR-113 (manufactured by Catalyst Kasei Kogyo Co., Ltd .: solid content 20 wt%), which was hollow silica, and diluted to obtain a low refractive index component (c) having a solid content of 3.1 wt%.
[Adjustment of low refractive index component (d)]
2.75 g of methacryloxypropyltrimethoxysilane and 0.34 g of 10 wt% formic acid aqueous solution were mixed with 20 g of through silica TR-113 (manufactured by Catalyst Kasei Kogyo Co., Ltd .: solid content 20 wt%), which is a hollow silica, at 70 ° C. Stir for hours. Then, 2.76 g of 2-perfluoro-7-methyloctylethyl acrylate and 0.115 g of 2,2-azobisisobutyronitrile were added, followed by heating and stirring at 90 ° C. for 1 hour. The obtained liquid was diluted with isopropyl alcohol to obtain a low refractive index component (d) having a solid concentration of 3.6% by weight.

[Adjustment of low refractive index component (e)]
2.75 g of methacryloxypropyltrimethoxysilane and 0.34 g of 10 wt% formic acid aqueous solution were mixed with 20 g of through silica TR-113 (manufactured by Catalyst Kasei Kogyo Co., Ltd .: solid content 20 wt%), which is a hollow silica, at 70 ° C. Stir for hours. Then, 2.76 g of 2-perfluorohexylethyl acrylate and 0.115 g of 2,2-azobisisobutyronitrile were added, and the mixture was heated and stirred at 90 ° C. for 1 hour. The obtained liquid was diluted with isopropyl alcohol to obtain a low refractive index component (e) having a solid content concentration of 3.6% by weight.

[Coating 1]
2-hydroxy-2-methyl-1-phenyl-propane- was added to 100 parts by weight of a solution in which the low refractive index component (a) and the high refractive index component (a) were mixed at a weight ratio of 4: 6. 1 part by weight of 1-one was added.

[Coating agent 2]
2-hydroxy-2-methyl-1-phenyl-propane- was added to 100 parts by weight of a solution in which the low refractive index component (a) and the high refractive index component (a) were mixed at a weight ratio of 4: 6. 3 parts by weight of 1-one was added.

[Coating agent 3]
2-hydroxy-2-methyl-1-phenyl-propane- was added to 100 parts by weight of a solution in which the low refractive index component (a) and the high refractive index component (a) were mixed at a weight ratio of 4: 6. 5 parts by weight of 1-one was added.

[Coating 4]
2-hydroxy-2-methyl-1-phenyl-propane- was added to 100 parts by weight of a solution in which the low refractive index component (a) and the high refractive index component (a) were mixed at a weight ratio of 4: 6. 7 parts by weight of 1-one was added.

[Coating agent 5]
2-hydroxy-2-methyl-1-phenyl-propane- was added to 100 parts by weight of a solution in which the low refractive index component (a) and the high refractive index component (a) were mixed at a weight ratio of 4: 6. 10 parts by weight of 1-one was added.

[Coating agent 6]
The low refractive index component (a) and the high refractive index component (a) were mixed at a weight ratio of 4: 6.

[Coating agent 7]
Bis (2.4.6-trimethylbenzoyl) -phenylphosphine was added to 100 parts by weight of a solution in which the low refractive index component (a) and the high refractive index component (a) were mixed at a weight ratio of 4: 6. 1 part by weight of fin oxide was added.
[Coating 8]
2-hydroxy-2-methyl-1-phenyl-propane- was added to 100 parts by weight of a solution in which the low refractive index component (b) and the high refractive index component (a) were mixed at a weight ratio of 4: 6. 1 part by weight of 1-one was added.

[Coating agent 9]
1 part by weight of methylbenzoyl formate was added to 100 parts by weight of a solution in which the low refractive index component (c) and the high refractive index component (a) were mixed at a weight ratio of 4: 6.

[Coating agent 10]
1 part by weight of 2-hydroxy-2-methyl-1-phenyl-propan-1-one was added to 100 parts by weight of only the low refractive index component (a).

[Coating agent 11]
2-hydroxy-2-methyl-1-phenyl-propane- was added to 100 parts by weight of a solution in which the low refractive index component (a) and the high refractive index component (b) were mixed at a weight ratio of 4: 6. 1 part by weight of 1-one was added.

[Coating agent 12]
2-hydroxy-2-methyl-1-phenyl-propane- was added to 100 parts by weight of a solution in which the low refractive index component (d) and the high refractive index component (a) were mixed at a weight ratio of 4: 6. 1 part by weight of 1-one was added.

[Coating agent 13]
2-hydroxy-2-methyl-1-phenyl-propane- was added to 100 parts by weight of a solution in which the low refractive index component (e) and the high refractive index component (a) were mixed at a weight ratio of 4: 6. 1 part by weight of 1-one was added.

[Preparation of antireflection film]
As a support substrate, Lumiclear SR-HC (manufactured by Toray Film Processing Co., Ltd.) in which a hard coat paint was applied and cured on a PET resin film was used. On the surface of the supporting substrate on which the hard coat paint is applied and cured, the paint described in Examples 1 to 8 and Comparative Examples 1 to 5 is applied at 100 ° C. using a bar coater (# 10). Dry for 1 minute, and use a 160 W / cm high-pressure mercury lamp lamp (manufactured by Eye Graphics Co., Ltd.) to emit UV light with an illuminance of 600 W / cm ² and an integrated light amount of 800 mJ / cm ² under an oxygen concentration of 0.1%. Irradiated to produce an antireflection film.

[Evaluation of antireflection film]
The manufactured antireflection film was subjected to the following performance evaluation, and the obtained results are shown in Table 1. Unless otherwise specified, in each of the examples and comparative examples, the measurement was performed three times at different locations for one sample, and the average value was used.

[Antireflection performance]
The antireflection performance was evaluated using a spectrophotometer UV-3100 manufactured by Shimadzu Corporation in the wavelength range of 400 nm to 800 nm, and the minimum value of light reflectance (bottom reflectance) and delta reflectance were measured.

[Abrasion resistance]
The steel wool (# 0000) with a load of 250 g / cm ² was placed vertically on the antireflection film, and the approximate number of scratches observed when the length of 1 cm was reciprocated 10 times was described.

Number of scratches 0 or more and less than 5 ◎
5 or more and less than 15
15 or more ×
If the number of scratches was less than 15, the result was acceptable.

[transparency]
Transparency was determined by measuring the haze value. The measurement was based on JIS K 7136 (2000) using a haze meter manufactured by Nippon Denshoku Industries Co., Ltd.

[Alkali resistance]
A 1% by weight NaOH solution was dropped on the surface (low refractive index layer side) opposite to the support substrate of the antireflection film sample, and after 15 minutes, wiping was performed using gauze. By observing the surface state after wiping, it was visually determined whether or not the surface was damaged. If there was no trace of the droplet, the evaluation was ○, and if the trace was confirmed, the evaluation was ×. Of the three samples with different locations for one sample, the most evaluated result is adopted.

[Refractive index of inorganic particles]
The dispersion liquid of inorganic particles is taken in an evaporator and the dispersion medium is evaporated. This is dried at 120 ° C. to obtain a powder. A standard refracting liquid having a known refractive index is dropped onto a glass drop of a few drops, and the above powder is mixed therewith. The above operation was carried out with various standard refractive liquids, and the standard refractive liquid of the mixed liquid (in many cases when the paste became transparent) was measured as the refractive index of the inorganic particles.
[Presence or absence of two-layer interface]
By observing the cross section using a transmission electron microscope (TEM), the presence or absence of the interface between the two layers was determined. The presence / absence of the interface was determined according to the following method. An image taken by a TEM at a magnification of 200,000 times was attached to presentation software (Microsoft Power Point 2003) using a scanner. Next, image control processing (contrast was set to 90%) of the attached photograph was performed to enhance the contrast. At this time, when a clear boundary could be drawn at the interface between one layer and the other layer, it was considered that there was a clear interface.
[Individual refractive index of two layers]
The refractive index of each of the two layers in the present invention is measured with a reflection spectral film thickness meter (trade name [FE-3000], manufactured by Otsuka Electronics Co., Ltd.). Using FE-Analysis], the refractive index at 550 nm was determined according to the method described in [Film thickness measuring apparatus general catalog P6 (nonlinear least squares method)] manufactured by Otsuka Electronics Co., Ltd.

The optical constants (C ₁ , C ₂ , C ₃ ) are calculated by the least square method (curve fitting method) using Cauchy's dispersion formula (Formula 1) as an approximate expression of the wavelength dispersion of the refractive index, and the refractive index at 550 nm is calculated. It was measured.
[Number average particle diameter of particles]
The number average particle diameter of the particles was determined with a transmission electron microscope. The magnification was set to 500,000, and the outer diameters of 10 particles existing in the screen were measured and taken as the average value. If there are no 10 particles in the screen, observe another spot under the same conditions, measure the outer diameter of the particles present in the screen, and measure the outer diameter of 10 particles in total. Averaged.

  Here, the outer diameter means the maximum diameter of the particle (that is, the longest diameter of the particle and indicates the longest diameter in the particle). Similarly, in the case of a particle having a cavity inside, the maximum diameter of the particle is also defined. To express.

  In Table 1, the number average particle size of the fluorinated inorganic particles is the number average particle size of the inorganic particles before the fluorination treatment.

  As is apparent from Table 1, when the alkylphenone derivative was included (Examples 1 to 8), the film was a well-balanced film excellent in antireflection properties, scratch resistance, alkali resistance and transparency. In the case where the alkylphenone derivative was not included (Comparative Examples 1 and 2), the antireflection property and transparency were good, but the scratch resistance and alkali resistance were insufficient.

  In the case where the surface treatment with a fluorine compound was not performed in the low refractive index component, in Comparative Examples 3 and 4, the transparency was good, but the scratch resistance, antireflection property, and alkali resistance were lacking. Even when the high refractive index component was not included (Comparative Example 5), although the transparency was good, the scratch resistance, antireflection property and alkali resistance were insufficient.

Claims (11)

A method for producing an antireflection film having two layers having different refractive indexes on at least one surface of a supporting substrate,
A step of applying and drying and curing the coating composition once on at least one surface of the supporting substrate,
The coating composition contains two or more kinds of inorganic particles,
At least one kind of inorganic particles in the two or more kinds of inorganic particles are inorganic particles whose surface is treated with a fluorine compound,
Furthermore, the manufacturing method of the antireflection film characterized by including an alkylphenone derivative.   The method for producing an antireflection film according to claim 1, wherein the alkylphenone derivative is a hydroxyalkylphenone derivative. The inorganic particles surface-treated with the fluorine compound are particles obtained by surface-treating silica particles with a fluorine compound (hereinafter, silica particles surface-treated with a fluorine compound are referred to as fluorine-treated silica particles),
3. The method for producing an antireflection film according to claim 1, wherein the other inorganic particles excluding the fluorinated silica particles are inorganic particles having a higher refractive index than the silica particles. The surface treatment method for obtaining the fluorine-treated silica particles is characterized in that the silica particles are treated with a compound represented by the following general formula (I) and further treated with a compound represented by the general formula (II): The manufacturing method of the antireflection film of Claim 3.
_{^{A-R 1 -SiR 2 n (}} OR 3) 3-n Formula (I)
B—R ⁴ —Rf Formula (II)
(A and B in the above general formula represent a reactive double bond group, R ¹ and R ⁴ represent an alkylene group having 1 to 3 carbon atoms and an ester structure derived therefrom, and R ² and R ³ represent Hydrogen or an alkyl group having 1 to 4 carbon atoms, Rf represents a fluoroalkyl group, n represents 0, 1 or 2 and each may have a side chain in the structure. The silica particles are silica particles having cavities therein and / or silica particles having pores,
The method for producing an antireflection film according to claim 3 or 4, wherein the number average particle diameter of the silica particles is from 1 nm to 200 nm.   The inorganic particles having a higher refractive index than the silica particles are made of a metal oxide having a number average particle diameter of 1 nm to 150 nm and a refractive index of 1.60 to 2.80. 6. A method for producing an antireflection film according to any one of 5 above.   The method for producing an antireflection film according to claim 6, wherein the metal oxide is indium-containing tin oxide (ITO) and / or antimony-containing tin oxide (ATO).   The antireflection film which can be obtained with the manufacturing method in any one of Claim 1 to 7.   An image display device comprising the antireflection film according to claim 8. A coating composition comprising two or more kinds of inorganic particles and an alkylphenone derivative,
The coating composition, wherein the two or more kinds of inorganic particles include silica particles (fluorinated silica particles) surface-treated with a fluorine compound and a metal oxide. The surface treatment for obtaining the fluorine-treated silica particles is characterized in that the silica particles are treated with a compound represented by the following general formula (I) and further treated with a compound represented by the general formula (II): Item 11. The coating composition according to Item 10.
_{^{A-R 1 -SiR 2 n (}} OR 3) 3-n Formula (I)
B—R ⁴ —Rf Formula (II)
(A and B in the above general formula represent a reactive double bond group, R ¹ and R ⁴ represent an alkylene group having 1 to 3 carbon atoms and an ester structure derived therefrom, and R ² and R ³ represent Hydrogen or an alkyl group having 1 to 4 carbon atoms, Rf represents a fluoroalkyl group, n represents 0, 1 or 2 and each may have a side chain in the structure.