JPH09222503A - Production of antireflection film and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily form a layer having low refractive index and enough adhesion property between layers and to provide an excellent antireflection film which prevents reflection of external light in a display device and the like. SOLUTION: This antireflection film is obtd. by forming a low refractive index layer on a base body or by successively forming an intermediate layer and a low refractive index layer on a base body. In this case, the low refractive index layer contains at least one kind of fluorine-contg. polymer particles having <=200nm average particle size. This layer contains has microvoids among the fine particles formed by two or more particles stacked. Before forming the low refractive index layer, the base body or the intermediate layer to be in contact with the layer is subjected to at least one kind of surface treatment selected from among corona discharge treatment, flame treatment, UV treatment and glow discharge treatment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to adhesion between layers of an anti-reflection film for external light and durability in a display device, particularly a display such as an LCD (liquid crystal display device), which is excellent in mass productivity and anti-contamination property. Regarding improvement.

[0002]

2. Description of the Related Art Hitherto, as an antireflection film for light having a wavelength range such as visible light, a multilayer film in which transparent thin films such as metal oxides are laminated has been used. While a single-layer film is effective for monochromatic light, it cannot effectively prevent reflection of light having a certain wavelength range. It becomes an effective antireflection film in the region. Therefore, as the conventional antireflection film, a laminate of three or more layers of metal oxide or the like has been used by a means such as physical vapor deposition. However, in order to form an antireflection film having a multilayer structure, it is necessary to perform physical vapor deposition with the film thickness controlled with high accuracy many times according to the relationship between the refractive index and the film thickness of each layer that is optimally designed in advance. It was very expensive. Further, in order to improve the scratch resistance of the surface or stain resistance such as fingerprint adhesion, it is necessary to newly provide a layer made of a fluorine-containing resin.

In addition to the method using a multilayer film as described above, there is conventionally known a method of obtaining an effective antireflection effect by using a film whose refractive index gradually changes at the interface with air. For example, in JP-A-2-245702, SiO ₂ ultrafine particles and MgF ₂ ultrafine particles having a refractive index intermediate between those of a glass substrate and MgF ₂ are mixed and coated on a glass substrate,
By gradually decreasing the mixing ratio of SiO ₂ and increasing the mixing ratio of MgF ₂ from the glass substrate surface toward the coating film surface, the change in the refractive index at the interface between the coating surface and the glass substrate becomes gentle, and antireflection is prevented. It is stated that the effect can be obtained.

Further, Japanese Patent Application Laid-Open No. 5-13021 discloses that
It is described that in an antireflection film using ultrafine particles having a low refractive index such as MgF ₂ and SiO ₂ , the smallest reflectance is obtained when the ultrafine particles are regularly arranged on the substrate.

Further, Japanese Patent Application Laid-Open No. 7-92305 discloses that
The inner layer is made of methyl methacrylate, methacrylic acid, trifluoroethyl acrylate, and N-isobutoxymethyl acrylamide, and the outer layer is made of styrene, acrylic acid, and butyl acrylate. It is noted that the light transmittance was increased by 5% by the antireflection film which was exposed to the surface and had irregularities formed thereon.

Further, in Japanese Patent Laid-Open No. 7-168006, ultrafine particles obtained by applying a mixture of tetrafluoroacrylate and MgF ₂ sol and then polymerizing and curing the organic fluorine compound by electron beam irradiation. It is described that the amount of light transmission is improved by about 6% by the antireflection film in which the surface is completely exposed and becomes an uneven surface.

However, the above-mentioned Japanese Patent Laid-Open No. 24570/1990.
Since the antireflection film described in JP-A No. 2 is obtained by stacking coating films having different mixing ratios, there is a problem that the film formation is complicated and the refractive index is difficult to control. Further, in the antireflection film of JP-A-5-13021, it is difficult to gently change the refractive index because the ultrafine particles in the outermost layer are covered with the binder, and the baking temperature is high. Therefore, there is a problem that the base material used is limited. Further, the antireflection film described in JP-A-7-92305 has a refractive index of 1.428 because the ultrafine particles containing a fluorine-containing resin contain a resin component containing no fluorine, and thus a sufficient antireflection effect is obtained. Not available, Japanese Patent Laid-Open No. 7-168
The antireflection film described in 006 has a problem that a sufficient antireflection effect cannot be obtained because the refractive index of MgF ₂ itself, which is also used as ultrafine particles, is 1.38.

Therefore, the inventors have found that the average particle size is 200 nm.
It is possible to form a low refractive index layer by a film containing the following fine particles of a fluoropolymer, and by stacking at least two or more fine particles, the film containing microvoids on average between the fine particles, It has been found that an excellent antireflection effect can be obtained by forming an antireflection film including a refraction layer.

However, simply laminating the fine particles with each other causes insufficient adhesion between the particles, resulting in insufficient film strength and poor durability.

[0010]

An object of the present invention is to improve the film strength and durability of a low refractive index layer in an antireflection film including a low refractive layer containing microvoids.

[0011]

The above-mentioned problems can be solved by the following antireflection film. (1) An antireflection film in which a low refractive index layer is provided on a support, or an intermediate layer and a low refractive index layer are sequentially provided on a support,
The low refractive index layer is a layer containing at least one kind of fluorine-containing polymer fine particles having an average particle diameter of 200 nm or less, and this layer contains microvoids among the fine particles by stacking at least two fine particles. Before the formation of the low refractive index layer, the support or intermediate layer in contact with the low refractive index layer is subjected to at least one surface treatment selected from corona discharge treatment, flame treatment, UV treatment and glow discharge treatment. And a method for producing an antireflection film. (2) The method for producing an antireflection film as described in (1), wherein the low refractive index layer is formed within 10 months after the surface treatment. (3) The method for producing an antireflection film as described in (1), wherein the intermediate layer is one in which the low refractive index layer has a higher refractive index than that. (4) The method for producing an antireflection film as described in (1), wherein the surface is antiglare treated. (5) A display device provided with the antireflection film of (1).

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION It can be explained as follows that an excellent antireflection effect was obtained by the antireflection film of the present invention.

FIG. 1 shows an antireflection film consisting of a low refractive index layer containing fine particles of a fluoropolymer. In the figure, 1 is a layer in which a fine particle layer and air are mixed (microvoid-containing layer), 3
Is the substrate. The microvoids are present in one layer dispersed almost uniformly. The low refractive index layer is provided on the outermost surface of the transparent base material on which antireflection is to be performed. The present invention is characterized in that voids between particles and voids formed between particles and a substrate are uniform, and that the voids have a size that does not scatter light. Therefore, although the low refractive index layer is microscopically a microvoid-containing fine particle porous film, it can be macroscopically regarded as a uniform low refractive index layer.

The refractive index of air is 1, and the refractive index of the fine particles in the present invention is higher than the refractive index of 1 of air. The refractive index of the low refractive index layer of the present invention can be made lower than the refractive index of the material by the volume fraction of microvoids by making the polymer fine particles. Therefore, the refractive index of the microvoid-containing layer 1 located between the air layer and the substrate 3 is located between the refractive index of the air layer and the refractive index of the fine particles themselves.

26% of voids (microvoids) are formed between the fine particles when the fine particles having the monodisperse particle size are packed in the closest direction, and increase to 48% in the case of simple cubic filling. Actually, since the particle size has a certain distribution, the actual content of microvoids slightly deviates from the calculated value.
It is possible to form a microvoid film of about 50%. The porosity also changes depending on the method of adhering the particles to each other and the adhering conditions. If the content of microvoids is too high, the mechanical strength of the film is impaired. Therefore, from the viewpoint of film strength, the content of microvoids is preferably 50% or less.

The particle size of the fine particles used in the present invention is 200 nm or less and 5 nm or more, and preferably 50 nm or less for improving the film strength. Examples of such fine particles include polymer latex. When the particle size of the fine particles increases, forward scattering increases, and when it exceeds 200 nm, scattered light is colored, which is not preferable.

The monomer unit of the polymer forming the fine particles is not particularly limited, and examples thereof include acrylic acid esters such as ethyl acrylate and 2-ethylhexyl acrylate,
In addition to methacrylic acid esters such as methyl methacrylate and ethyl methacrylate, styrene derivatives, vinyl chloride polymers, acrylamides, methacrylamides, acrylonitrile derivatives, urethanes and the like can be mentioned. Further, in order to enhance the adhesive force between the laminated fine particles, an isocyanate group, an aziridine group, an aldehyde group,
It is effective to introduce a functional group such as an epoxy group.
In practice, it is necessary to use a homopolymer or copolymer of a fluorine-containing monomer or a copolymer of a fluorine-containing monomer and a non-fluorine monomer in order to realize a low refractive index.
Alternatively, the particles may be made into a core-shell and a polymer having a high fluorine content may be used in the core part to introduce a thermal cross-linking group into the shell part or to obtain a polymer having a functional group capable of reacting with a silane coupling agent. It is valid.

The fluorine-containing monomer will be listed below, but the invention is not limited thereto. In particular, perfluoro-2,2-dimethyl-1,3-dioxole or tetrafluoroethylene is preferably used because it has a very low refractive index.

[0019]

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In the formula, R ¹ represents a hydrogen atom, a methyl group or a fluorine atom, and p and n represent a positive integer. Moreover, the following monomers can be mentioned.

Further, the following monomers can be used.

[0022]

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[0023]

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Examples of the fluorine-containing polymer using the above-mentioned monomer include the following.

[0025]

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The refractive index of the fluoropolymer decreases almost linearly with the content of fluorine atoms, and the refractive index of the layer further decreases with an increase in the content of microvoids. In order to sufficiently lower the refractive index of the layer as a combination of both, the fluoropolymer content is 0.35 weight% or more,
A layer containing fine fluorine-containing polymer particles containing 0.75 weight fraction or less of fluorine atoms is 0.10 volume fraction or more and 0.5
It is necessary to include microvoids having a volume fraction of 0 or less.

The polymer particles of the antireflection film in the present invention may be either crystalline or amorphous.
Until now, polymer particles having crystallinity could not be used as a film of an optical material to reduce light transmittance, but by using fine particles having a particle size sufficiently smaller than the wavelength of light, Even if it has crystallinity, it can be used as an antireflection film without reducing the light transmittance.

The fine particle layer having such a low refractive index is
Not only the single-layer film shown in FIG. 1 but also the uppermost layer of the multilayer film can be used. FIG. 2 shows an antireflection film in which a layer 2 having a refractive index higher than that of the substrate is provided on a substrate film, and a layer containing fluoropolymer fine particles is further provided thereon. Obtaining an effective antireflection film in a wider wavelength range by forming a multilayer in this way is based on the same principle as that of the prior art. For example, JP-A-59-
As shown in Japanese Patent No. 50401, in a two-layer film,
By setting the refractive index n1 and film thickness d1 of the first layer film in contact with the substrate and the refractive index n2 and film thickness d2 of the second layer in contact with the first layer to satisfy the following relationship, The action of is optimized. The antireflection conditions for such a multilayer film have been known for a long time. First layer mλ / 4 × 0.7 <n1d1 <mλ / 4 × 1.3 Second layer nλ / 4 × 0.7 <n2d2 <nλ / 4 × 1.3 where m is a positive integer and n is an odd number Is a positive integer.

As the substrate for forming the antireflection film of the present invention, various plastic films can be used, and cellulose derivatives (eg, triacetyl- (TAC), diacetyl-, propionyl-, butanoyl-, acetylpropionyl-acetate) can be used. , Nitro-, etc.), polyamide,
Polycarbonate, polyester described in JP-B-48-40414 (especially polyethylene terephthalate, poly-1,4-cyclohexane dimethylene terephthalate,
Polyethylene 1,2-diphenoxyethane-4,4-dicarboxylate, polybutylene terephthalate, polyethylene naphthalate, etc.), polystyrene, polypropylene, polyethylene, polymethylpentene, polysulfone, polyethersulfone, polyarylate, polyetherimide Various transparent resins such as polymethyl methacrylate and the like are preferably used.

When used as a multilayer film, the following materials are used as materials for the high refractive index layer.

As the organic material, a film-forming substance having a refractive index higher than that of the low refractive index layer, such as polystyrene, polystyrene copolymer, polycarbonate, an aromatic ring other than polystyrene, a heterocyclic ring, an alicyclic ring group, or a substance other than fluorine is used. Various polymer compositions having a halogen group, various thermosetting resin-forming compositions using melamine resin, phenol resin, epoxy resin or the like as a curing agent, alicyclic or aromatic isocyanate, and urethane composed of these and polyol A forming composition and a composition containing various modified resins or prepolymers capable of radical curing by introducing a double bond into the above compound are preferably used. In addition, as the organic material in which the inorganic fine particles are dispersed, a material having a lower refractive index than that in the case where the organic material is used alone is generally used because the inorganic fine particles have a high refractive index. In addition to the organic materials described above, vinyl-based copolymers including acrylics, polyester (including alkyd) -based polymers, fibrin-based polymers, urethane-based polymers, and various curing agents for curing these, Various organic materials such as a composition having a curable functional group, which are transparent and can stably disperse the inorganic fine particles, can be used. Further, an organic-substituted silicon-based compound can be included therein.

These silicon compounds are represented by the general formula R ¹ aR ² b SiX _{4- (a} + _b) (wherein R ¹ and R ² are respectively an alkyl group, an alkenyl group,
Allyl group, or halogen group, epoxy group, amino group,
Hydrocarbon groups having a mercapto group, a methacryloxy group or a cyano group. X is a hydrolyzable substituent selected from alkoxyl, alkoxyalkoxyl, halogen and acyloxy groups. a and b are each 0, 1, or 2, and a + b is 1 or 2. ) Or a hydrolysis product thereof.

As the inorganic compound dispersed therein, oxides of metal elements such as aluminum, titanium, zirconium and antimony are preferably used. These may be provided in finely divided form as a powder or as a colloidal dispersion in water and / or other solvents. These are mixed and dispersed in the above organic material or organosilicon compound.

Inorganic materials which form a film and can be dispersed in a solvent or which are themselves liquid include alkoxides of various elements, salts of organic acids, and coordination compounds combined with a coordination compound. Examples thereof include titanium tetraethoxide, titanium tetra-i-propoxide, titanium tetra-n-propoxide, titanium tetra-n-butoxide,
Titanium tetra-sec-butoxide, titanium tetra-tert
-Butoxide, aluminum triethoxide, aluminum tri-i-propoxide, aluminum tributoxide, antimony triethoxide, antimony tributoxide, zirconium tetraethoxide, zirconium tetra-i-propoxide, zirconium tetra-n-
Propoxide, zirconium tetra-n-butoxide,
Zirconium tetra-sec-butoxide, metal alcoholate compounds such as zirconium tetra-tert-butoxide, further di-isopropoxytitanium bisacetylacetonate, di-butoxytitanium bisacetylacetonate, di-ethoxytitanium bisacetylacetonate, Bisacetylacetone zirconium, aluminum acetylacetonate, aluminum di-n-
Chelating compounds such as butoxide monoethyl acetoacetate, aluminum di-i-propoxide monomethyl acetoacetate, and tri-n-butoxide zirconium monoethyl acetoacetate, and also zirconium ammonium carbonate or an active inorganic polymer containing zirconium as a main component Can be given. In addition to those described above, various alkyl silicates or hydrolysates thereof, and finely divided silica, particularly silica gel dispersed in a colloidal form, are used as those which have a relatively low refractive index but can be used in combination with the above compounds.

The low refractive index antireflection layer of the present invention is generally well known, for example, dip coating method, air knife coating method, curtain coating method, roller coating method, wire bar coating method, gravure coating method, or US patent. It can be applied by an extrusion coating method using a hopper described in No. 2,681,294. Also, if necessary, US Pat. No. 2,761,
791, 3,508,947, 2,941,898
No. and 3,526,528, Yuji Harasaki, "Coating Engineering", page 253 (Published by Asakura Shoten in 1973).
And the like, two or more layers can be simultaneously coated.

The low refractive index antireflection layer of the present invention may be provided with a hard coat layer, a moisture proof, an antistatic layer or the like as an intermediate layer in addition to the high refractive index layer. Further, it may be a layer which has the respective purposes at the same time. As a material for forming the hard coat layer, silica-based materials can be used in addition to acrylic-based, urethane-based, and epoxy-based polymers.

The surface of the low refractive index antireflection film layer of the present invention may be made uneven by an organic or inorganic compound to provide an antiglare effect for scattering external light and preventing the reflection of a scene or the like. The anti-reflection film may be used alone or in combination with an anti-glare effect in a liquid crystal display (LCD),
Plasma display (PDP), electroluminescence display (ELD), cathode ray tube display (CR
By applying the present invention to an image display device such as T) and preventing reflection of external light, visibility can be significantly improved.

The antireflection film of the present invention can be provided directly on the above-mentioned base material or on the above-mentioned intermediate layer. However, the antireflection film can be easily formed without surface treatment of these lower layers. It is not preferable because it peels off or the film is removed. Next, the surface treatment of the present invention will be described. Examples of preferable surface treatment include glow discharge treatment, corona discharge treatment, ultraviolet (UV) treatment, and flame treatment. Among these, the glow discharge treatment and the corona discharge treatment are preferable. These treatments may be performed alone or in combination of two or more. These methods will be described in detail below. The glow treatment is a conventionally known method, for example, Japanese Examined Patent Publication Nos. 35-7578, 36-10336, 45-22004, and 45-2004.
22005, 45-2040, 46-434
80, JP-A-53-129262, US Pat. No. 3,0.
57,792, 3,057,795, 3,17
9,482, 3,288,638, 3,30
9,299, 3,424,735, 3,46
2,335, 3,475,307, 3,76
1,299, 4,072,769, British Patent 89
No. 1,469, No. 997,093, etc. can be used. With such a glow treatment, the most excellent adhesion effect can be obtained especially when water vapor is introduced into the atmosphere. In addition, this method suppresses the yellowing of the film,
It is also very effective in preventing blocking. The steam partial pressure when performing the glow treatment in the presence of steam is preferably 10% or more and 100% or less, and more preferably 40% or more and 90% or less. If it is less than 10%, it will be difficult to obtain sufficient adhesiveness. The gas other than water vapor is air composed of oxygen, nitrogen and the like.

Further, when the vacuum glow treatment is performed in a state where the lower layer to be surface-treated is heated, the adhesion is improved in a shorter time than the treatment at room temperature, which is effective. The preheating temperature is preferably 50 ° C or higher and Tg or lower, and 60 ° C or higher and Tg
The following is more preferable, and 70 ° C. or higher and Tg or lower is further preferable. Preheating at a temperature of Tg or higher deteriorates adhesion.
The degree of vacuum during the glow treatment is preferably 0.005 to 20 Torr. More preferably 0.02 to 2 Torr
It is. Further, the voltage is preferably between 500 and 5000V. More preferably, it is 500-3000V. The discharge frequency used is from direct current to several 1000 MHz, preferably 50 Hz to 20 MHz, as found in the prior art.
More preferably, it is 1 KHz to 1 MHz. Discharge intensity is 0.01 KV · A · min / m ^{2 to 5} KV · A · min /
m ² is preferable, more preferably 0.15 KV · A · min /
The desired adhesion performance can be obtained at m ^{2 to 1} KV · A · min / m ² .
It is preferable that the temperature of the support thus subjected to the glow treatment is immediately lowered by using a cooling roll.

Corona treatment is the most well-known method, and any conventionally known method, for example, Japanese Patent Publication No. 48-
5043, 47-51905, and JP-A-47-28.
067, 49-83767, 51-41770.
No. 51-131576 and the like. Discharge frequency is 50Hz-500
0 kHz, preferably 5 kHz to several 100 kHz is suitable. The processing strength of the object is 0.001K
V · A · min / m ^{2 to 5} KV · A · min / m ² , preferably 0.
01 KV · A · min / m ^{2 to 1} KV · A · min / m ² is suitable. The gap clearance between the electrode and the dielectric roll is 0.
A suitable size is 5 to 2.5 mm, preferably 1.0 to 2.0 mm.

UV treatment is carried out according to Japanese Patent Publication No. 43-2603.
It is preferable that the treatment is performed according to the processing methods described in JP-B-43-2604 and JP-B-45-3828. The mercury lamp is a high-pressure mercury lamp or a low-pressure mercury lamp composed of a quartz tube, and it is preferable that the wavelength of ultraviolet rays is 180 to 380 nm. Regarding the method of ultraviolet irradiation, the irradiation light amount is 20 to 10000 (m in the case of a high-pressure mercury lamp having a main wavelength of 365 nm.
J / cm ² ), more preferably 50 to 2000 (m
J / cm ² ). In the case of a low-pressure mercury lamp having a main wavelength of 254 nm, the irradiation light amount is 100 to 10,000 (mJ).
/ Cm ² ), more preferably 200 to 1500 (m
J / cm ² ).

The flame treatment method may be either natural gas or liquefied propane gas, but the mixing ratio with air is important. In the case of propane gas, a preferable mixing ratio of propane gas / air is 1/14 to 1/22, preferably 1/16 to 1/19 by volume ratio. In the case of natural gas, it is 1/6 to 1/10, preferably 1/7 to 1/9. Flame treatment is 1~50Kcal / m ^2, more preferably performed in the range of 3~30Kcal / m ^2. Further, it is more effective if the distance between the tip of the internal flame of the burner and the support is less than 4 cm. A frame processing device manufactured by Kasuga Electric Co., Ltd. can be used as the processing device. Further, the backup roll that supports the support during the flame treatment is a hollow roll, and it is preferable that the backup roll is water-cooled by cooling water and always treated at a constant temperature.
In the present invention, it is preferable to form the low refractive index layer within 10 months after the surface treatment of the support or the intermediate layer in contact with the low refractive index layer.

[0043]

The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. Example 1 The fine particles (B-1, B-2) shown in Table 1 were obtained by emulsion polymerization.

[0044]

[Table 1]

The triacetyl cellulose (TAC) film was subjected to the following surface treatments (E-1, E-2) and then 1
Four days later, a fine particle mixed aqueous solution (B-1: B-2 = 80: 20 by weight) prepared by blending the above fine particles was applied using a bar coater.

(E-1) Corona discharge treatment Using a solid state corona treatment machine 6KVA model manufactured by Pilar Co., Ltd., both sides of a 30 cm wide support were subjected to 2 at room temperature.
Process at 0 m / min. The support was treated at 0.375 kV · A · min / m ² from the current and voltage readings at this time. The processing frequency at this time is 9.6 kHz,
Gap clearance between electrode and dielectric roll is 1.6m
m. (E-2) Glow Discharge Treatment Four rod-shaped electrodes having a hollow section to be a coolant flow path and having a columnar shape with a diameter of 2 cm and a length of 150 cm were fixed at 10 cm intervals in an insulating state. This electrode was fixed in a vacuum tank, the film was moved 15 cm away from the electrode, the film was run so as to face the electrode surface, and the transport speed was controlled so that the surface treatment was performed for 2 seconds. The film has a diameter of 50 before passing through the electrodes.
The heating roll is arranged so as to come into contact with the heating roll having a temperature controller of cm for 3/4 round, and the temperature of the film is set to 11
After the temperature was set to 5 ° C., glow discharge treatment was performed. The degree of vacuum in the tank is 0.12 Torr, and the moisture content of the atmospheric gas is 75%.
The discharge frequency was 27 kHz, the output was 2500 W, and the treatment intensity was 0.5 kV · A · min / m ² . The film after the electric discharge treatment was brought into contact with a cooling roll having a diameter of 30 cm and equipped with a temperature controller, and after being brought to 25 ° C., it was wound. The tension between the heating roll and the cooling roll was 5 kg / m to convey the support.

The coated material was dried at 80 ° C. for 30 minutes to form a low refractive index layer made of fluorine-containing fine particles and having a thickness of 100 nm. With respect to the obtained films (X-1, X-2), the refractive index and the luminous reflectance were measured, and the film was heated at 60 ° C. in a high temperature bath at 9 ° C.
A durability test was conducted at 5% for 500 hours. Table 2 shows the results
It was shown to.

Comparative Example 1 Triacetyl cellulose (TA
C) The same fine particle mixture as used in Example 1 was applied onto the film using a bar coater. It was dried at 80 C for 30 minutes to form a low refractive index layer made of fluorine-containing fine particles and having a film thickness of 100 nm. The same test as in Example 1 was performed on the obtained film (X-3). The results are shown in Table 2.

Comparative Example 2 The same fine particle mixture as used in Example 1 was applied using a bar coater 12 months after the glow discharge treatment was applied to the triacetyl cellulose (TAC) film. 80
Dry with C for 30 minutes, film thickness 100 consisting of fluorine-containing fine particles
A low refractive index layer having a thickness of nm was formed. The same test as in Example 1 was performed on the obtained film (X-4). The results are shown in Table 2.

[0050]

[Table 2]

As is clear from the table, in the two examples of Example 1, no bubbles or peeling occurred in the durability test, and Comparative Example 2
It can be seen that the durability is greatly improved compared to.
It can be seen that in Comparative Example 2, the durability is improved as compared with Comparative Example 1, but the performance is insufficient as compared with Example 1.

Example 2 A toluene solution containing 3% by weight of polystyrene (trade name: Topolex GPPS525-51 (manufactured by Mitsui Toatsu)) was applied to a TAC film by using a spin coater to have a refractive index of 1.585 and a film thickness of 160 nm. The high refractive index layer of was formed.
14 days after the same glow discharge treatment as in Example 1, the same fine particle dispersion as in Example 1 was applied and dried, and the obtained film (X-5) was evaluated in the same manner as in Example 1. The results are shown in Table 3.

Comparative Example 2 TAC formed with the same high refractive index layer as used in Example 2
The same fine particle dispersion as in Example 1 was applied and dried without surface treatment, and the obtained film (X-6) was evaluated in the same manner as in Example 1. The results are shown in Table 3.

[0054]

[Table 3]

As is clear from this example, the antireflection film of the present invention has not only the performance equivalent to that of the multilayer evaporation type antireflection film which has been conventionally used but also sufficient durability. I understand.

[0056]

EFFECTS OF THE INVENTION The surface treatment of the present invention can improve the adhesion to a fluorine-containing material, which usually has low surface energy and insufficient adhesion to a multilayer, and cracks even in a durability test at high humidity. It is possible to provide an antireflection film that does not peel off.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an antireflection film made of a layer comprising a fluoropolymer fine particle of the present invention.

FIG. 2 shows a layer comprising the fluoropolymer fine particles of the present invention,
FIG. 2 shows a cross-sectional view of an antireflection film made of a layer having a higher refractive index than a substrate.

[Explanation of symbols]

 1: Fluorine-containing polymer fine particle layer 2: High refractive index layer 3: Base material

Claims (5)

[Claims] 1. An antireflection film comprising a low-refractive index layer provided on a support or an intermediate layer and a low-refractive index layer provided in this order on the support, wherein the low-refractive index layer has an average particle size of 200 nm. A layer containing at least one kind of the following fluoropolymer fine particles, which contains microvoids between the fine particles by stacking at least two or more fine particles, and before forming the low refractive index layer A method for producing an antireflection film, which comprises subjecting a support or an intermediate layer in contact with it to at least one surface treatment selected from corona discharge treatment, flame treatment, UV treatment and glow discharge treatment. 2. The method for producing an antireflection film according to claim 1, wherein the low refractive index layer is formed within 10 months after the surface treatment. 3. The method for producing an antireflection film according to claim 1, wherein the intermediate layer has a higher refractive index than the low refractive index layer. 4. The method for producing an antireflection film according to claim 1, wherein the surface is antiglare treated. 5. A display device provided with the antireflection film according to claim 1.