JP2003202406A - Antireflection film and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antireflection film having high antireflection performance with a monolayer antireflection layer. <P>SOLUTION: The antireflection film has on the surface of a plastic film substrate 1 a cured coating layer 2 of a coating material composition consisting essentially of a silicone resin comprising a partial hydrolyzate and/or a hydrolyzate of a hydrolyzable organosilane and fine hollow silica particles of 5 nm to 2 μm average particle diameter with a hollow formed in an outer shell. The cured coating layer 2 comprising the silicone resin and the fine hollow silica particles has a low refractive index and the antireflection film has high antireflection performance with an antireflection layer 3 formed from the monolayer cured coating layer 2. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antireflection film and a display device to which the antireflection film is attached.

[0002]

2. Description of the Related Art In order to impart an antireflection function to an image display surface of a display, conventionally, an antireflection film was directly coated on the display. However, with the flattening of displays, it is common practice to use an antireflection film that is formed by providing an antireflection layer on the surface of a plastic film and then attach this antireflection film to the device surface of the display or the front plate for protection. It has become a target.

In this antireflection film, the antireflection layer is generally formed of a plurality of layers of a high refractive material and a low refractive material in order to obtain high antireflection ability. However, when the antireflection layer is formed in a plurality of layers in this way, many steps for forming the antireflection layer are required,
There is a problem in terms of manufacturing cost, etc.Although the antireflection film having a multi-layer structure can suppress the bottom reflectance to a low value, the reflectance in the visual region becomes high, and in this respect, there is a problem in the antireflection ability. Have.

[0004]

Here, in order to form the antireflection layer as a single layer, it is necessary to form the antireflection layer with a low refractive index material, but a fluororesin which is a typical low refractive index material. However, because of its low mechanical strength, it is not practical because scratches easily occur when it is formed on the surface of a display or the like.

The present invention has been made in view of the above points, and an object of the present invention is to provide an antireflection film having a single antireflection layer and high antireflection performance, and a display device.

[0006]

The antireflection film according to claim 1 of the present invention comprises a partially hydrolyzed organosilane and / or a hydrolyzable organosilane on the surface of a plastic film substrate.
Alternatively, a cured coating layer of a coating material composition containing, as essential components, a silicone resin composed of a hydrolyzate and hollow silica fine particles having an average particle diameter of 5 nm to 2 μm and having cavities formed inside the outer shell are provided. It is characterized by that.

According to a second aspect of the present invention, in the first aspect, a hard coat layer having a hardness higher than that of the plastic film substrate is provided between the surface of the plastic film substrate and the cured coating layer of the coating material composition. It is characterized by consisting of.

The invention of claim 3 is characterized in that, in claim 1 or 2, the surface of the cured coating layer of the coating material composition is provided with an antifouling layer having water and oil repellency. It is a thing.

The invention according to claim 4 is the plastic film substrate according to any one of claims 1 to 3, wherein a pressure-sensitive adhesive layer is provided on the surface of the plastic film substrate opposite to the surface on which the cured coating layer of the coating material composition is provided. It is characterized by comprising.

The invention of claim 5 is characterized in that, in any one of claims 1 to 4, the cured coating layer of the coating material composition has a layer thickness of 0.05 to 0.2 μm. Is.

According to the invention of claim 6, in any one of claims 1 to 5, the silicone resin of the coating material composition is a tetrafunctional hydrolyzable compound represented by SiX ₄ (X is a hydrolytic substituent). It is characterized by being a tetrafunctional silicone resin composed of a partial hydrolyzate and / or a hydrolyzate of an organosilane.

The invention of claim 7 is characterized in that, in claim 6, the tetrafunctional hydrolyzable organosilane represented by SiX ₄ is tetramethoxysilane of X═OCH ₃ .

The invention of claim 8 is the silicone resin of the coating material composition according to any one of claims 1 to 7, which is applied to the surface of a quartz glass substrate to a thickness of 100 nm. It is characterized in that a cured coating film obtained by firing at a temperature of 10 ° C. has a surface water drop contact angle of 10 ° or less.

A ninth aspect of the present invention is the silicone resin of the coating material composition according to any one of the first to eighth aspects, which has a weight average molecular weight of 200 to 2000.
It is characterized in that it is made of a material within the range of.

Further, the invention of claim 10 is based on claims 1 to 9.
In any one of the above, as a silicone resin of the coating material composition, a tetrafunctional organoalkoxysilane represented by SiX ₄ (X = OR, R is a monovalent hydrocarbon group) is used in a molar ratio [H ₂ O] / [ OR] is 1.0 or more, and a partial hydrolyzate and / or a hydrolyzate obtained by a hydrolysis reaction in the presence of an acid or alkali catalyst are used. Is.

A display device according to claim 11 of the present invention is characterized in that the antireflection film according to any one of claims 1 to 10 is attached to the surface of the display surface of the image display. To do.

According to a twelfth aspect of the present invention, a display device according to any one of the first to the first aspects is provided on at least one surface of a front plate arranged on the front side of the image display.
The antireflection film as described in any one of No. 0 is attached.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.

The plastic film substrate as the substrate of the antireflection film is not particularly limited as long as it has a high light-transmitting property. For example, polycarbonate, acrylic resin, PET (polyethylene terephthalate),
Examples thereof include films (including sheets) of thermoplastic resins such as TAC (triacetyl cellulose). The thickness of the plastic film substrate is not particularly limited, but it is generally about 70 to 200 μm.

An antireflection film can be formed by providing an antireflection layer on the surface of the plastic film substrate. The present invention is a partial hydrolyzate of a hydrolyzable organosilane and / or Silicone resin consisting of hydrolyzate and average particle size of 5n
An antireflection layer is formed by a cured coating layer of a coating material composition containing, as an essential component, hollow silica fine particles having a diameter of m to 2 μm and having cavities formed inside the outer shell. Hereinafter, this coating material composition will be described in detail.

As the hollow silica fine particles contained in the coating material composition, those having an average particle diameter of 5 nm to 2 μm and having cavities formed inside the outer shell are used. If it is such a thing, although not limited in particular, the following things can be used concretely. For example, hollow silica fine particles having cavities inside an outer shell made of a silica-based inorganic oxide can be used. The silica-based inorganic oxides include (A) a single layer of silica, (B) a single layer of a composite oxide composed of silica and an inorganic oxide other than silica, and (C) the (A) layer and the (B) layer. And a double layer. The outer shell may be a porous one having pores, or may be one in which the pores are closed by an operation described later to seal the cavity. The outer shell comprises a first silica coating layer on the inner side and a second silica coating layer on the outer side.
It is preferably a plurality of silica-based coating layers composed of a silica coating layer. By providing the second silica coating layer on the outer side, it is possible to close the fine pores of the outer shell to densify the outer shell, and to obtain hollow silica fine particles in which the inner cavity is sealed with the outer shell. is there.

The thickness of the first silica coating layer is 1 to 50 nm,
Particularly, it is preferable to set it in the range of 5 to 20 nm. When the thickness of the first silica coating layer is less than 1 nm, it becomes difficult to maintain the particle shape when removing a part of the constituent components of the spherical core particles described later, and there is a possibility that hollow silica fine particles cannot be obtained. When the second silica coating layer is formed, a partial hydrolyzate of an organosilicon compound may enter the pores of the core particles, which makes it difficult to remove the core particle constituents. Conversely, the thickness of the first silica coating layer is 50 nm
If it exceeds, it may be difficult to remove the components constituting the core particles in the next step, and the ratio of the cavities in the hollow silica fine particles may be reduced, resulting in insufficient reduction of the refractive index. Further, the thickness of the outer shell is preferably in the range of 1/50 to 1/5 of the average particle diameter described later. This is because when removing a part of the constituent components of the core particles, when the hollow silica fine particles whose outer shell thickness is too thin compared to the average particle size are dissolved and removed by an acid, the first silica is repeated by the repeated operation. This is because the pores of the coating layer become too large or are destroyed and the spherical shape of the core particles cannot be maintained. The thickness of the second silica coating layer may be such that the total thickness of the second silica coating layer and the first silica coating layer is in the range of 1 to 50 nm, and particularly in the range of 20 to 49 nm in terms of densifying the outer shell. Is.

The solvent used when the hollow silica fine particles are prepared and / or the gas that permeates when dried is present in the cavity. Further, a precursor substance for forming a cavity, which will be described later, may remain in the cavity. The precursor material may adhere to the outer shell and remain slightly, or may occupy most of the inside of the cavity. Here, the precursor substance is a porous substance remaining after removing a part of the constituent components from the core particles for forming the first silica coating layer. As the core particles, porous composite oxide particles composed of silica and an inorganic oxide other than silica are used. Examples of the inorganic oxide include Al ₂ O ₃ , B ₂ O ₃ , TiO ₂ , ZrO ₂ and SnO.
₂ , Ce ₂ O ₃ , P ₂ O ₅ , Sb ₂ O ₃ , MoO ₃ , ZnO ₂ ,
One or more of WO _{3 and the} like can be mentioned. Two
TiO ₂ —Al ₂ O ₃ , Ti
O ₂ -ZrO ₂ or the like can be exemplified. The solvent or gas also exists in the pores of this porous material. When the removal amount of the constituent components at this time is increased, the volume of the cavity is increased, hollow silica fine particles having a low refractive index are obtained, and the transparent coating obtained by blending the hollow silica fine particles has a low refractive index and antireflection performance. Excel.

As described above, the average particle diameter of the hollow silica fine particles is in the range of 5 nm to 2 μm. When the average particle size is smaller than 5 nm, the effect of lowering the refractive index due to the hollow is small, and when the average particle size is larger than 2 μm, the transparency is extremely deteriorated and the diffuse reflection (Anti-Glare) contributes. Will become bigger. A more preferable range of the average particle size of the hollow silica fine particles is 5 to 100 nm. The average particle diameter can be determined by the dynamic light scattering method.

Then, a dispersion of hollow silica fine particles can be prepared by going through the following steps (a) to (c).

(A) Preparation of Nuclear Particle Dispersion As the silicate, one or more silicates selected from alkali metal silicates, ammonium silicates and organic base silicates are preferably used. Examples of alkali metal silicates include sodium silicate (water glass) and potassium silicate, examples of organic bases include quaternary ammonium salts such as tetraethylammonium salt, amines such as monoethanolamine, diethanolamine, and triethanolamine. The ammonium silicate or organic base silicate also includes an alkaline solution obtained by adding ammonia, a quaternary ammonium hydroxide, an amine compound or the like to a silicic acid solution. As the acidic silicic acid solution, a silicic acid solution obtained by removing an alkali by treating an alkali silicate aqueous solution with a cation exchange resin or the like can be used. In particular, the pH is _{2 to} 4 and the SiO ₂ concentration is 7% by weight or less. Acidic silicic acid solutions are preferred. As a raw material for the inorganic oxide, it is preferable to use an alkali-soluble inorganic compound, and examples thereof include alkali metal salts or alkaline earth metal salts, ammonium salts, and quaternary ammonium salts of the above-mentioned metal or nonmetal oxo acids. More specifically, sodium aluminate,
Suitable are sodium tetraborate, zirconyl ammonium carbonate, potassium antimonate, potassium stannate, sodium aluminosilicate, sodium molybdate, ammonium cerium nitrate, sodium phosphate and the like.

To prepare the core particle dispersion,
The alkaline aqueous solution of the above-mentioned inorganic compound is individually prepared or a mixed aqueous solution is prepared in advance, and depending on the composite ratio of the target silica and the inorganic oxide other than silica, this aqueous solution is prepared.
Gradually add to an alkaline aqueous solution having a pH of 10 or more with stirring. The addition ratio of the silica raw material and the inorganic compound added to the alkaline aqueous solution represents the silica component by SiO ₂ ,
When the inorganic compound other than silica is represented by MOX, the molar ratio MOX / SiO ₂ is 0.3 to 1.0, and particularly 0.35 to 0.8.
It is preferable to set it in the range of 5. MOX / S
When iO ₂ is less than 0.3, the above-mentioned cavity volume is not sufficiently large, while when MOX / SiO ₂ exceeds 1.0, it becomes difficult to obtain spherical core particles, and as a result, the resulting hollow The proportion of void volume in the silica fine particles is reduced. If the molar ratio MOX / SiO ₂ is in the range of 0.3 to 1.0,
The structure of the core particle is mainly a structure in which silicon and an element other than silicon are alternately bonded with oxygen interposed. That is, an oxygen atom is bonded to the four bonds of the silicon atom, and a large number of structures in which an element M other than silica is bonded to the oxygen atom are generated.
When removing the element M other than silica in the step (c) described later,
By accommodating the element M, silicon atoms can also be removed as a silicic acid monomer or oligomer.

Further, seed particles are used when preparing the dispersion of core particles.
It is also possible to use the dispersion liquid of 1. as a starting material. in this case
In addition, as seed particles, SiO₂, Al₂O₃, TiO₂, Z
rO ₂, SnO₂And CeO₂Inorganic oxides such as these or these
Complex oxide of, for example, SiO₂-Al₂O₃, TiO₂−
Al₂O₃, TiO₂-ZrO₂, SiO₂-TiO₂, Si
O₂-TiO₂-Al₂O₃Fine particles such as
These sols can be used. Such seed particles
The dispersion liquid of can be prepared by a conventionally known method.
Wear. For example, metal salts or metals corresponding to the above inorganic oxides
The mixture of salts, metal alkoxide, etc.
To be added and hydrolyzed and aged if necessary
Therefore, it can be obtained. Adjusted to pH 10 or above
An aqueous solution of the above compound was added to the seed particle dispersion liquid as described above.
Do not stir in the same manner as adding to the aqueous potassium solution.
Added from above. Also in this case, the pH of the dispersion liquid is particularly controlled.
You don't have to. In this way, seed particles are used as seeds and nuclear particles are used.
When grown, the average particle size of grown particles can be controlled.
It is easy and it is possible to obtain a product having a uniform particle size. seed
Addition of silica raw material and inorganic oxide to be added to the particle dispersion
The addition rate is the same as when adding to the alkaline aqueous solution described above.
The same range. The above silica raw material and inorganic oxide raw material
Has a high solubility on the alkaline side. But Naga
Et al., When both are mixed in this highly soluble pH range,
Of oxo acid ions such as acid ion and aluminate ion
The solubility decreases and these compounds precipitate and colloid particles
Particle growth or particle formation by depositing on seed particles.
Long happens. Therefore, during precipitation and growth of colloidal particles
Therefore, the pH control as in the conventional method is not always necessary.

In the preparation of the above-mentioned core particle dispersion liquid, as a silica raw material, R _n SiX _(4-n) (wherein R is a carbon number 1 to
10 unsubstituted or substituted hydrocarbon groups, X is an alkoxide group having 1 to 4 carbon atoms, silanol group, halogen or hydrogen, n
May be added to the alkaline aqueous solution. Specific examples of the organic silicon compound include tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane,
Phenyltrimethoxysilane, diphenyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, isobutyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (βmethoxyethoxy) Silane, 3,3,3-
Trifluoropropyltrimethoxysilane, methyl-
3,3,3-trifluoropropyldimethoxysilane,
β- (3,4 epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxytripropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-methacryloxypropyl Methyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane,
γ-methacryloxypropylmethyldiethoxysilane,
γ-methacryloxypropyltriethoxysilane, N-
β (aminoethyl) γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane , Γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane,
Examples thereof include trimethylsilanol, methyltrichlorosilane, methyldichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, vinyltrichlorosilane, trimethylbromosilane and diethylsilane. Since the above-mentioned organosilicon compounds in which n is 1 to 3 have poor hydrophilicity, it is preferable to hydrolyze them in advance so that they can be uniformly mixed in the reaction system. For the hydrolysis, a well-known method for hydrolyzing these organosilicon compounds can be adopted. When a basic catalyst such as a hydroxide of an alkali metal, ammonia water, or an amine is used as the hydrolysis catalyst, it is also possible to remove these basic catalysts after the hydrolysis and use it as an acidic solution. Further, when the hydrolyzate is prepared using an acidic catalyst such as an organic acid or an inorganic acid, it is preferable to remove the acidic catalyst by ion exchange or the like after the hydrolysis. The resulting hydrolyzate of the organosilicon compound is preferably used in the form of an aqueous solution. Here, the aqueous solution means a state in which the hydrolyzate has transparency, not a white turbid state as a gel.

(B) Formation of First Silica Coating Layer As the silica raw material to be added, a silicic acid solution obtained by dealkalizing an alkali metal salt of silica (water glass) is particularly preferable. When the dispersion medium of the core particles is water alone or the ratio of water to the organic solvent is high, coating treatment with a silicic acid solution is also possible. When a silicic acid solution is used, a predetermined amount of silicic acid solution is added to the dispersion, and at the same time alkali is added to deposit the silicic acid solution on the surface of the core particles. Further, a hydrolyzable organic silicon compound can also be used as the silica raw material. As the hydrolyzable organic silicon compound, a compound represented by the general formula R _n Si (O
R ') _(4-n) (In this formula, R and R'are hydrocarbon groups such as alkyl groups, aryl groups, vinyl groups and acryl groups, and n =
Alkoxysilanes represented by 0, 1, 2 or 3) can be used, and tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane and tetraisopropoxysilane are particularly preferable.

As a method of addition, a solution obtained by adding a small amount of an alkali or an acid as a catalyst to a mixed solution of these alkoxysilane, pure water and alcohol is added to the core particle dispersion liquid to hydrolyze the alkoxysilane. The resulting silicic acid polymer is deposited on the surface of the core particles. At this time, the alkoxysilane, alcohol, and catalyst may be simultaneously added to the dispersion liquid. Ammonia, alkali metal hydroxides, and amines can be used as the alkali catalyst. As the acid catalyst, various inorganic acids and organic acids can be used. It is also possible to perform the coating treatment by using the alkoxysilane and the above silicic acid solution in combination.
Further, if necessary, an inorganic compound other than the silica source may be used in combination for the coating treatment, and the alkali-soluble inorganic compound used for the preparation of the core particles may be used.
The amount of the silica raw material and the inorganic compound added as necessary is set to an amount sufficient to form the coating layer having the above-mentioned thickness. The first silica coating layer needs to be porous having a large number of pores.

(C) Cavity formation By removing some or all of the elements constituting the core particles from the core particles coated with the first coating layer,
It is possible to prepare hollow silica fine particles having cavities inside the first coating layer as an outer shell. To remove some or all of the elements that make up the core particles, dissolve or remove by adding a mineral acid or an organic acid to this core particle dispersion,
Alternatively, a method of contacting with a cation exchange resin for ion exchange removal can be exemplified. The concentration of the core particles in the core particle dispersion at this time varies depending on the treatment temperature,
0.1 to 50% by weight, especially 0.5 to 2 in terms of oxide
It is preferably in the range of 5% by weight. If it is less than 0.1% by weight, the dissolution of silica in the first silica coating layer may occur, and at the same time, the treatment efficiency is poor due to the low concentration. Further, if the concentration of the core particles exceeds 50% by weight, it becomes difficult to remove the desired amount of the elements forming the core particles in a small number of times. This is because elements other than silica can be removed only by dissolution by addition of acid, but due to the low solubility of silica, even if a silica monomer or the like is generated, it is immediately precipitated in the particles, and as a result, silica is This is because the amount removed along with the element (3) is reduced and the cavities are not efficiently generated.

The removal of the above-mentioned elements is carried out by setting the MOX / SiO ₂ of the obtained silica-based fine particles to 0.0001 to 0.2, particularly to 0.2.
It is preferable to carry out until 0001 to 0.1. The dispersion liquid from which the elements have been removed can be washed by a known washing method such as ultrafiltration. In this case, if a part of alkali metal ions, alkaline earth metal ions, ammonium ions and the like in the dispersion liquid is previously removed and then ultrafiltration is performed,
A sol in which fine hollow silica particles having high dispersion stability are dispersed can be obtained. An organic solvent-dispersed sol can be obtained by substituting with an organic solvent as needed. The hollow silica fine particles dispersed in the dispersion sol thus obtained have a first silica layer having a porous outer shell, and the inner cavity contains a solvent and / or a gas. Further, if the core particles are not completely removed, the porous substance remains in the cavities. Therefore, the obtained hollow silica fine particles have a low refractive index, and the cured coating formed using the hollow silica fine particles has a low refractive index, and a cured coating excellent in antireflection performance can be obtained.

Then, after the step (c) of the method for preparing the hollow silica fine particle dispersion liquid is further added with the step of forming the second silica coating layer, the hollow silica fine particles whose outer shell is composed of a plurality of coating layers. A dispersion can be prepared. In this step, R _n SiX _(4-n) (wherein R is an unsubstituted or substituted hydrocarbon group having 1 to 10 carbon atoms, X is an alkoxide group having 1 to 4 carbon atoms, a silanol group, halogen or hydrogen, As the organosilicon compound represented by n is an integer of 0 to 3, the same organosilicon compound as shown in step (b) can be used. In the above formula, when an organic silicon compound with n = 0 is used, it can be used as it is, but when an organic silicon compound with n = 1 to 3 is used, partial hydrolysis of the organic silicon compound used in the step (a) is performed. It is preferable to use the same one. By forming the second silica coating layer, the thickness of the outer shell can be adjusted, and the thickness of the outer shell can be finally set to 1 to 50 nm. Further, since the removing step as described above is not performed after the second silica coating layer is formed, the coating layer has only fine pores, and the pores of the coating layer can be reduced or reduced by the hydrothermal treatment or heat treatment step described later. Densification due to disappearance becomes easy.

For forming the second silica coating layer, n = 1 to 1
When the organosilicon compound of 3 is used, the dispersibility in an organic solvent is good, and a silica-based fine particle dispersion liquid having a high affinity with a resin can be obtained. Therefore, it can be used after being surface-treated with a silane coupling agent or the like, but such treatment may be particularly required because of its excellent dispersibility in an organic solvent and affinity with a resin. Absent. When a fluorine-containing organosilicon compound is used to form the second silica coating layer, the obtained particles have a lower refractive index and dispersibility in an organic solvent because the coating layer containing F atoms is formed. It is possible to obtain a hollow silica fine particle dispersion liquid having a good affinity with a resin. Examples of such a fluorine-containing organosilicon compound include 3,3,3-trifluoropropyltrimethoxysilane, methyl-3,3,3-trifluoropropyldimethoxysilane, heptadecafluorodecylmethyldimethoxysilane, and heptadecafluorodecyl. Examples thereof include trichlorosilane, heptadecafluorodecyltrimethoxysilane, trifluoropropyltrimethoxysilane, and tridecafluorooctyltrimethoxysilane.

The hollow silica fine particles dispersed in the dispersion liquid thus obtained are treated in step (a) except that the outer shell is composed of a porous first silica layer and a second silica layer.
The same hollow silica fine particles as those obtained through (c) to (c) are obtained.

Further, by further hydrothermally treating the hollow silica fine particle dispersion liquid obtained as described above, it is possible to obtain a hollow silica fine particle dispersion liquid having a densified outer shell. That is, if necessary, an aqueous alkali solution is added to the hollow silica fine particle dispersion liquid on which the second silica coating layer is formed, and the pH is adjusted to preferably in the range of 8 to 13, and heat treatment is performed. The heat treatment temperature at this time is preferably in the range of 50 to 350 ° C, particularly preferably in the range of 100 to 300 ° C. By this hydrothermal treatment, the pores of the coating layer can be reduced or eliminated, and the solvent and / or gas, and further the porous substance remains in the internal cavity of the densified outer shell of the hollow silica fine particles. It will be. In the heat treatment,
The hollow silica fine particle dispersion liquid obtained in the step (c) can be diluted in advance or concentrated for treatment. Finally, the hydrothermally treated dispersion may be washed in the same manner as in the above step (c).

Further, the hollow silica fine particle dispersion liquid in which the outer shell is composed of a plurality of coating layers, or the hollow silica fine particle dispersion liquid in which the outer shell is densified, is one in which the cavity is not completely sealed by the outer shell. After drying, heat treatment is performed at 400 to 1200 ° C. (temperature of 1/3 of melting point of silica to less than melting point) under atmospheric pressure or reduced pressure to obtain hollow silica fine particles in which cavities are sealed by an outer shell. You can
If the heat treatment temperature is less than 400 ° C, the pores of the coating layer cannot be completely closed, while the heat treatment temperature is 120
If the temperature exceeds 0 ° C., the hollow silica fine particles may fuse with each other,
It may not be possible to maintain a spherical shape. The hollow silica fine particles thus obtained do not have a solvent in their cavities, and thus it is difficult to obtain a dispersion liquid with an ordinary solvent. However, since the inside consists only of gas or gas and a porous material, the refractive index of the particles is extremely low, and the cured coating obtained using these particles has a low refractive index, and the coated article on which this cured coating is formed is Excellent antireflection performance. Further, the film in which the particles are laminated has an excellent heat insulating effect, and the particles are also useful as a heat insulating material.

Next, as the silicone resin contained in the coating material composition, one containing a partial hydrolyzate and / or a hydrolyzate of a hydrolyzable organosilane can be used, and this silicone resin is a matrix. It becomes a material. As the hydrolyzable organosilane, one having 1 to 4 reactive substituents bonded to a silicon element can be used, and among them, one having 4 reactive substituents bonded to a silicon element, that is, It is preferable to use a tetrafunctional hydrolyzable organosilane represented by SiX ₄ (X is a hydrolytic substituent). A tetrafunctional silicone resin containing a partial hydrolyzate and / or a hydrolyzate of a tetrafunctional hydrolyzable organosilane is excellent in the dispersion stability of hollow silica fine particles, and compared with a trifunctional or bifunctional silicone resin. The matrix material has a low refractive index, and further, the crosslink density of the cured coating can be further increased to obtain high mechanical strength.

For example, as the tetrafunctional hydrolyzable organosilane represented by SiX _4, there may be mentioned a tetrafunctional organoalkoxysilane represented by the following chemical formula (1) in which X = OR.

Si (OR) ₄ (1) “R” in the alkoxide group “OR” in the above chemical formula (1) is not particularly limited as long as it is a monovalent hydrocarbon group, but the number of carbon atoms is not limited. A monovalent hydrocarbon group of 1 to 8 is preferable, and examples thereof include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, peptyl group, and octyl group. it can. Among the alkyl groups contained in the alkoxide group, those having 3 or more carbon atoms may be linear ones such as n-propyl group and n-butyl group, isopropyl group, It may have a branch such as an isobutyl group and a t-butyl group. Among these, as the tetrafunctional organoalkoxysilane, it is preferable to use tetramethoxysilane in which R is a methyl group, that is, X═OCH ₃ . By using a silicone resin composed of a hydrolyzate of tetramethoxysilane as a matrix material, a cured coating having excellent mechanical strength can be obtained.

The preparation of the tetrafunctional silicone resin can be carried out by hydrolyzing the tetrafunctional hydrolyzable organosilane such as the tetrafunctional organoalkoxysilane (hereinafter, also referred to as partial hydrolysis). Here, the weight average molecular weight of the obtained tetrafunctional silicone resin is not particularly limited, but in order to obtain the mechanical strength of the cured coating by a smaller proportion of the tetrafunctional silicone resin with respect to the hollow silica fine particles. The weight average molecular weight is preferably in the range of 200 to 2000. If the weight average molecular weight is less than 200, the film-forming ability may be poor, and if it exceeds 2000, the cured film may have poor mechanical strength.

Further, usually, 4 obtained by hydrolyzing a tetrafunctional hydrolyzable organosilane to cause a condensation reaction
The functional silicone resin is polymerized by leaving some unreacted groups, that is, the hydrolysis substituents X in the molecule. Thus, even if the unreacted group remains in the molecule, when the heat treatment is performed at a high temperature of more than 300 ° C. after forming the cured film, the unreacted group is decomposed and adversely affects the refractive index. However, when the heat treatment is carried out at a low temperature (100 to 300 ° C.), the unreacted groups remain in the cured coating without being decomposed, which may adversely affect the refractive index of the matrix material. There is. Therefore, 4
As the functional silicone resin, it is preferable to use a completely reacted hydrolyzate rather than a partially hydrolyzed product. Since the completely reacted hydrolyzate has only -OH group at the molecular end, when the hydrolyzate alone, that is, the tetrafunctional silicone resin alone forms a cured film, the surface of the cured film is very difficult. The hydrophilicity is excellent, and the contact angle of water droplets on the surface is small. Specifically, as a tetrafunctional silicone resin, this is applied on the surface of a quartz glass substrate at a film thickness of 10
It is preferable to use a cured coating film obtained by coating so as to have a thickness of 0 nm and baking at 100 ° C. so that the contact angle of water droplets on the surface is 10 ° or less (the practical lower limit is 0 °). That is,
When such a tetrafunctional silicone resin is used as a matrix material, unreacted groups do not remain even when the cured coating is treated at a low temperature, and it is possible to easily suppress an increase in the refractive index of the cured coating. On the contrary, if a tetrafunctional silicone resin having a contact angle of water droplets on the surface of more than 10 ° is used, it may be difficult to suppress an increase in the refractive index of the cured coating unless the cured coating is treated at a high temperature. .

When the above-mentioned tetrafunctional organoalkoxysilane is used when preparing the tetrafunctional silicone resin, the amount of water to be added for hydrolysis is not particularly limited, but In order to reduce the number of alkoxide groups in the reaction, the molar equivalent of water (H ₂ O) to the hydrolyzable substituent (OR), that is, the molar ratio [H
₂ O] / [OR] is preferably 1.0 or more,
It is more preferable to add water so as to be 1.0 or more and 5.0 or less and to hydrolyze. If it is less than 1.0, the amount of unreacted alkoxide groups increases, which may adversely affect the refractive index of the cured film.
If it is more than 0, the condensation reaction will proceed extremely, which may lead to gelation of the coating material composition.

Further, when the tetrafunctional silicone resin is hydrolyzed, its concentration is in the range of 5% by weight or more and 20% by weight or less of solid content in terms of SiO _{2 with} respect to the total amount of the tetrafunctional silicone resin and water. Preferably there is. If the amount of the tetrafunctional silicone resin is less than 5% by weight, the amount of unreacted alkoxide groups may increase even if the above-described preferable amount of water is added, which may adversely affect the refractive index of the cured film. If the concentration is more than 20% by weight, the coating material composition may be gelated even if the above-mentioned preferable amount of water is added.

The catalyst used as necessary when hydrolyzing a tetrafunctional hydrolyzable organosilane such as a tetrafunctional organoalkoxysilane is not particularly limited, but the time required for the production process is not limited. From the viewpoint of shortening, an acidic catalyst is preferable. Such an acidic catalyst is not particularly limited, but for example, acetic acid, chloroacetic acid,
Organic acids such as citric acid, benzoic acid, dimethylmalonic acid, formic acid, propionic acid, glutaric acid, glycolic acid, maleic acid, malonic acid, toluenesulfonic acid and oxalic acid,
Examples thereof include inorganic acids such as hydrochloric acid, nitric acid, and silane halides, acidic colloidal silica, acidic sol-like fillers such as titania oxide sol, and one or more of these can be used. Hydrolysis of the alkoxide may be carried out by heating, if necessary, and particularly 40 to 100
It is preferable to accelerate the hydrolysis reaction for 2 to 100 hours under the condition of ° C because the unreacted alkoxide group can be reduced to a minimum. If hydrolysis is performed outside the above temperature range or time range, unreacted alkoxide groups may remain. It should be noted that instead of the above acidic catalyst, an alkaline catalyst such as an aqueous solution of an alkali metal or alkaline earth metal hydroxide such as sodium hydroxide or calcium hydroxide, aqueous ammonia, or an aqueous solution of amines may be used. There is no end.

Further, it is preferable to further add organozirconium to the coating material composition containing the hollow silica fine particles and the silicone resin as essential components. When the coating material composition containing the organic zirconium is applied to the substrate in this way, the condensation reaction at the time of forming the cured film is promoted, the crosslink density in the cured film is increased, and the water resistance and the water resistance of the cured film are increased. This is because the alkalinity can be improved.

The above organic zirconium is not particularly limited, but for example, the general formula ZrO _n R ² _{m can be used.}
(OR ¹ ) _p (m, p are integers from 0 to 4, n is 0 or 1, 2)
n + m + p = 4), and the functional group (R ¹ ) of the alkoxide group (OR ¹ ) in this chemical formula is the same as that in chemical formula (1). Further, as R ² , for example, C ₅
H ₇ O ₂ (acetylacetonate complex) or C ₆
Examples thereof include H ₉ O ₃ (ethyl acetoacetate complex). Further, as OR ¹ and R ² , a plurality of types may be present in one molecule. In particular, as organic zirconium, Zr (OC ₄ H ₉ ) ₄ , Zr (OC ₄ H 9
₉ ) ₃ (C ₅ H ₇ O ₂ ) and Zr (OC ₄ H ₉ ) ₂ (C ₅ H
_The use of at least one of ₇ O ₂ ) (C ₆ H ₉ O ₃ ) can further improve the mechanical strength of the cured film. For example, when a cured coating film is formed using a coating material composition having a low ratio of silicone resin to hollow silica fine particles, the cured coating film may have insufficient mechanical strength. However, the mechanical strength of the cured film can be improved by adding the above-mentioned organozirconium. Moreover, after coating this coating material composition on a substrate, it is kept at a relatively low temperature.
Even if the heat treatment is performed at 00 ° C., it is possible to obtain the strength equivalent to that when the heat treatment is performed at a high temperature exceeding 300 ° C.

The amount of organozirconium added is Zr.
It is preferably 0.1 to 10% by weight in terms of O ₂ with respect to the total solid content in the coating material composition.
If the addition amount is less than 0.1% by weight, the effect of the organic zirconium may not be observed, and conversely, if it is more than 10% by weight, the coating material composition may gel or aggregate.

In addition to the hollow silica fine particles, silica particles in which the outer shell is not hollow (hereinafter also simply referred to as "silica particles") can be added to the coating material composition. This is because it is possible to improve the mechanical strength of the cured film formed by this coating material composition, and also to improve the surface smoothness and crack resistance.

The form of the above silica particles is not particularly limited, and may be, for example, a powder form or a sol form. When the silica particles are used in a sol form, that is, colloidal silica, it is not particularly limited, but for example, a water-dispersible colloidal silica or a hydrophilic organic solvent-dispersed colloidal such as alcohol can be used. . Generally, such colloidal silica contains 20 to 50% by weight of silica as a solid content, and the amount of silica can be determined from this value.

When water-dispersible colloidal silica is used, the water present in the colloidal silica other than the solid content can be used for hydrolysis of the hydrolyzable organosilane. Therefore, it is necessary to add the water of the water-dispersible colloidal silica to the amount of water used for this hydrolysis. The water-dispersible colloidal silica is usually made of water glass, and a commercially available product can be easily obtained and used.

The organic solvent-dispersible colloidal silica can be easily prepared by substituting the organic solvent for water in the above water-dispersible colloidal silica. Similar to the water-dispersible colloidal silica, a commercially available product can be easily obtained and used as such an organic solvent-dispersed colloidal silica. In the organic solvent-dispersible colloidal silica, the type of organic solvent in which the colloidal silica is dispersed is not particularly limited, and examples thereof include methanol, ethanol, isopropanol (IPA), and n.
-Lower aliphatic alcohols such as butanol and isobutanol, ethylene glycol, ethylene glycol monobutyl ether, ethylene glycol derivatives such as ethylene glycol monoethyl ether, diethylene glycol, diethylene glycol derivatives such as diethylene glycol monobutyl ether, and hydrophilicity such as diacetone alcohol Organic solvents can be used, and one or more selected from the group consisting of these can be used. Furthermore, in combination with these hydrophilic organic solvents,
One or more of toluene, xylene, hexane, heptane, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, methyl ethyl ketoxime and the like can be used.

Further, the amount of the silica particles, that is, the one in which the inside of the outer shell is not hollow, is preferably 0.1 to 30% by weight based on the total solid content in the coating material composition. If it is less than 0.1% by weight, the effect due to the addition of the silica particles may not be observed,
On the other hand, if it exceeds 30% by weight, the refractive index of the cured film may be increased, which may have an adverse effect.

Further, since the coating material composition according to the present invention forms a cured film having a low refractive index, this cured film may be colored. In that case, the color of the cured film can be adjusted by previously including a pigment compound in the coating material composition. The dye compound is not particularly limited to inorganic or organic, and a commercially available product may be added in an appropriate amount so that a desired color tone is obtained within a range that does not significantly affect the refractive index of the cured film. Furthermore, a leveling agent or a viscosity modifier may be added to the coating material composition, if necessary.

The coating material composition according to the present invention can be obtained by using the above-mentioned silicone resin as a matrix material, adding hollow silica fine particles thereto, and further adding other components as required. it can. At this time, in the coating material composition,
The weight ratio of the hollow silica fine particles to the other components is not particularly limited, but is preferably in the range of hollow silica fine particles / other components (solid content) = 95/5 to 50/50, Preferably 95/5 to 75/25
Is. When the number of hollow silica fine particles is more than 95, it may be difficult to obtain the mechanical strength of the cured film, and when it is less than 50, the effect of exhibiting a low refractive index may be reduced.

The coating material composition obtained as described above may be diluted with an organic solvent or water if necessary, and when preparing the coating material composition, individual components are required in advance. It may be diluted with an organic solvent or water accordingly. The organic solvent used for dilution is not particularly limited, but examples thereof include lower aliphatic alcohols such as methanol, ethanol, isopropanol (IPA), n-butanol and isobutanol, ethylene glycol, ethylene glycol monobutyl ether. , Ethylene glycol derivatives such as acetic acid ethylene glycol monoethyl ether, diethylene glycol, diethylene glycol derivatives such as diethylene glycol monobutyl ether, diacetone alcohol, etc., and one or more kinds selected from the group consisting of these are used. be able to. Further, one or more of toluene, xylene, hexane, ethyl heptane acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, methyl ethyl ketoxime and the like can be used in combination with these hydrophilic organic solvents.

Then, the coating material composition prepared as described above is applied to the surface of the plastic film substrate 1 to form a coating film, and the coating film is dried and cured to cure the surface having a low refractive index. Coating layer 2
It is possible to obtain an antireflection film A as shown in FIG. 1A in which an antireflection layer 3 is formed by the cured film layer 2 having a low refractive index. According to this method, it is possible to easily obtain a cured coating layer 2 having a larger area than in the gas phase method or the liquid phase method, and it is possible to increase the processing speed. In addition, when the coating material composition is applied to the surface of the plastic film substrate 1, the cured film layer 2 is uniformly formed, or the adhesion between the cured film layer 2 and the plastic film substrate is improved. Thus, it is preferable to pre-clean the surface of the plastic film substrate 1. Examples of the pre-cleaning method include alkali cleaning, plasma cleaning, UV cleaning and corona discharge.

The method of coating the surface of the plastic film substrate 1 with the coating material composition is not particularly limited, but for example, brush coating, spray coating, dipping (dip coating, dip coating), Various ordinary coating methods such as roll coating, flow coating, curtain coating, knife coating, spin coating, table coating, sheet coating, sheet-fed coating, die coating and bar coating can be selected.

It is also preferable that the cured coating layer 2 formed on the surface of the plastic film substrate 1 is dried and then heat-treated. By this heat treatment, the mechanical strength of the cured coating layer 2 can be further improved. The temperature for the heat treatment is not particularly limited, but it is preferable to perform the treatment at a relatively low temperature of 100 to 150 ° C. for 1 to 30 minutes. Even if the heat treatment is performed at a low temperature in this way, it is possible to obtain the same mechanical strength as that when the heat treatment is performed at a high temperature, so that it is possible to reduce the film forming cost, and as in the case of the heat treatment at a high temperature, That is, the type of the plastic film substrate 1 is not restricted.

The thickness of the cured coating layer 2 formed on the surface of the plastic film substrate 1 varies depending on the required antireflection ability, but is preferably in the range of 0.05 to 0.2 μm. If the film thickness deviates from this range, it may not be possible to obtain sufficient antireflection properties.

In the antireflection film A according to the present invention obtained as described above, the cured coating layer 2 uses a partial hydrolyzate of a hydrolyzable organosilane and / or a silicone resin made of a hydrolyzate as a matrix material. Hollow silica fine particles having an average particle diameter of 5 nm to 2 μm are filled, and have a low refractive index of 1.35 or less, and the plastic film substrate 1 generally has a refractive index of 1.5 or more. Therefore, the antireflection layer 3 formed of the single-layer cured coating layer 2 can exhibit high antireflection performance.

The antireflection film A may need to be formed with a layer other than the antireflection layer 3 depending on the site where it is used. For example, when the antireflection film A is stretched and used as the outermost layer of an image display such as a liquid crystal display, the surface of the plastic film substrate 1 is protected so that the antireflection film A is not scratched by daily cleaning or the like. It is desirable to form the hard coat layer 4 having a hardness higher than that of the plastic film substrate 1.

The hard coat layer 4 is formed on the surface of the plastic film substrate 1, and the antireflection layer 3 is formed on the hard coat layer 4 as shown in FIG. . The hard coat layer 4 is not particularly limited as long as it is a material having high hardness and high transparency, but a curable acrylic resin such as UV curing, EB curing, or heat curing, a urethane resin, It can be formed of a silicone resin or the like. The hard coat layer 4 is preferably formed by selecting a material having a refractive index as close as possible to the refractive index of the plastic film substrate 1 in order to prevent multiple interference from occurring with the plastic film substrate 1. . The hard coat layer 4 can be formed by applying the above resin material to the surface of the plastic film substrate 1 and curing it, and the thickness of the hard coat layer 4 is not particularly limited. Although not present, it is generally set to about 1 to 20 μm.

An antifouling layer 5 may be formed on the surface of the antireflection film A. The antifouling layer 5 is the antireflection layer 3
It is formed on the surface side of, and can be formed of a material having water and oil repellency. The material for forming the antifouling layer 5 is not particularly limited, but a fluorosilane compound can be used. This fluorosilane compound is a fluorine compound having an alkoxysilano group, and is, for example, CF ₃ CF ₂ CH ₂ CH ₂ Si (OCH
₃ ) ₃ C ₃ F ₇ (OCF ₂ CF ₂ CF ₂ ) ₂₄ (OCF ₂ ) ₂ CH ₂
CH ₂ Si (OCH ₃ ) ₃ or the like can be used. The thickness of the antifouling layer 5 is preferably set to 0.03 μm or less so that the antireflection performance of the antireflection layer 3 is not adversely affected.

By incorporating photocatalyst fine particles in the cured coating layer 2 of the coating material composition for forming the antireflection layer 3, even if fingerprints or the like adhere to the surface of the antireflection layer 3, the light emitted from the display and It can be decomposed and removed by the photocatalytic effect by ambient light, and the surface of the antireflection layer 3 can be provided with antifouling property. When the photocatalyst is contained in this way to impart antifouling property to the antireflection layer 3, the antifouling layer 5 is not particularly necessary. Further, the surface of the antireflection layer 3 becomes hydrophilic due to the photocatalytic action,
Since the antistatic function is also exerted, the antistatic layer described later is not particularly required.

Titanium oxide, zinc oxide or the like can be used as the photocatalyst fine particles, and a visible light responsive photocatalyst is preferable. Examples of the visible light responsive photocatalyst include nitrogen-substituted titanium oxide in which a part of Ti—O bonds of titanium oxide fine particles is replaced with Ti—N, titanium oxide having oxygen defects in the lattice, and titanium oxide doped with chromium metal. Can be mentioned. The photocatalyst is generally a high-refractive material, and if the content is too large, it may adversely affect the antireflection performance. Therefore, the coating material composition should be 1 to 20% by weight based on the solid content of the cured coating layer 2. It is preferable to add a photocatalyst to the material to form the cured coating layer 2. still,
Similarly to the hollow silica fine particles, the photocatalyst fine particles can have a small apparent refractive index by hollowing the inside.

When the antireflection film A is required to have electromagnetic wave shielding properties and antistatic properties, a layer containing conductive metal fine particles between the plastic film substrate 1 and the antireflection layer 3, Alternatively, a layer having conductive metal oxide fine particles can be formed. The conductive metal fine particles and conductive metal oxide fine particles are not particularly limited, and any conventionally known one can be used.

Further, in the antireflection film A, an adhesive is applied to the surface of the plastic film substrate 1 opposite to the side where the antireflection layer 3 is provided, that is, the back surface of the plastic film substrate 1 to form an adhesive layer 6 Can be provided. As the adhesive, it is possible to use a conventionally known one, for example, vinyl acetate / vinyl chloride copolymer, polyvinyl ether, polyvinyl butyral, a rosin derivative as a tackifier on a polymer base such as polyacrylate,
A mixture of coumarone resin and terpene resin can be used. A release film 10 is stretched on the back side of the pressure-sensitive adhesive layer 6 as shown in FIG. 1C, and the release film 10 is used in a peeled state. By thus providing the pressure-sensitive adhesive layer 6 on the back side of the antireflection film A, the antireflection film A can be attached and used on any part of the display. Of course, it is also possible to use it for the antireflection film A without providing the adhesive layer 6. For example, when the antireflection film A is used for a touch panel, a transparent electrode may be formed on the back surface of the antireflection film A. it can.

The antireflection film A of the present invention produced as described above is an image of cathode ray tube (CRT), fluorescent display tube (FIP), plasma display (PDP), liquid crystal display (LCD), organic EL display, etc. It is used by being attached to the outermost surface of the display 7. In this case, as shown in FIG. 2A, the antireflection film A can be directly attached to the surface of the display surface 8 of the image display display 7 for use. See also FIG.
As shown in (b), when the front plate 9 for protection is arranged on the front side of the image display 7, the antireflection film A can be attached to the front plate 9 for use. When the antireflection film A is attached to the front plate 9 for use, it may be attached to one surface of the front plate 9 or both faces thereof.

[0071]

EXAMPLES Next, the present invention will be specifically described with reference to examples. Unless otherwise specified, all “parts” represent “parts by weight” and “%” represents “% by weight” except for the total light transmittance, reflectance and haze ratio, which will be described later. In addition, the molecular weight is measured by GPC (gel permeation chromatography), and the measurement model is HLC80 manufactured by Tosoh Corporation.
20 was used to prepare a calibration curve with standard polystyrene, and the calibration value was measured.

(Preparation Example 1 of coating material composition) To 121.6 parts of tetramethoxysilane and 24.3 parts of methyltrimethoxysilane, 420.5 parts of methanol was added, and further 16.8 parts of water and 0.01N. were mixed 16.8 parts of hydrochloric acid ( "H ₂ O" / "OR" = 0.5), which was mixed well by using a disper. This mixed solution was stirred for 2 hours in a constant temperature bath at 25 ° C., and the weight average molecular weight was adjusted to 800 to obtain a silicone resin (A).

Here, this silicone resin (A) is
Quartz glass washed with alkali (thickness 0.7 mm)
Is coated on one side of the with a spin coater and the film thickness is about 10
After forming a 0 nm coating, a cured coating was obtained by firing at 100 ° C. The water contact angle of this cured coating was measured by "CA-W150" manufactured by Kyowa Interface Science Co., Ltd., and it was 30 °.

Next, a hollow silica IPA (isopropanol) dispersion sol (solid content 20%, average primary particle diameter about 60 nm, outer shell thickness about 15 nm) as a hollow silica fine particle component was added to this silicone resin (A) solution: Catalysis Chemical Industry Manufactured by MHI), and added hollow silica fine particles / silicone resin (condensed compound conversion) at a weight ratio of 80/20 based on solid content, and further diluted with methanol so that the total solid content becomes 3%. A coating material composition (A) was prepared according to.

(Preparation example 2 of coating material composition) 412 parts of methanol was added to 152 parts of tetramethoxysilane, and further 18 parts of water and 18 parts of 0.01N hydrochloric acid ("H
₂ O ”/“ OR ”= 0.5) were mixed and mixed well using a disper. This mixed solution was stirred for 2 hours in a constant temperature bath at 25 ° C., and the weight average molecular weight was adjusted to 850 to obtain a silicone resin (B). The water contact angle of the cured film of the silicone resin (B) was measured in the same manner as in Preparation Example 1, and the result was 8 °.

Next, in this silicone resin (B) solution, a hollow silica IPA (isopropanol) dispersion sol (solid content 20%, average primary particle diameter about 60 nm, outer shell thickness about 15 nm) as a hollow silica fine particle component: Catalytic Chemical Industries Manufactured by MHI), and added hollow silica fine particles / silicone resin (condensed compound conversion) at a weight ratio of 80/20 based on solid content, and further diluted with methanol so that the total solid content becomes 3%. To prepare a coating material composition (B).

(Preparation example 3 of coating material composition) 356 parts of methanol was added to 208 parts of tetraethoxysilane, and further 18 parts of water and 18 parts of 0.01N hydrochloric acid ("H
₂ O ”/“ OR ”= 0.5) were mixed and mixed well using a disper. This mixed solution was stirred for 2 hours in a constant temperature bath at 25 ° C., and the weight average molecular weight was adjusted to 850 to obtain a silicone resin (C). The water contact angle of the cured film of the silicone resin (C) was measured in the same manner as in Preparation Example 1, and the result was 9 °.

Next, in this silicone resin (C) solution, as a hollow silica fine particle component, hollow silica IPA (isopropanol) -dispersed sol (solid content 20%, average primary particle diameter of about 60 nm, outer shell thickness of about 15 nm: Catalyst Chemical Industry) Manufactured by MHI), and added hollow silica fine particles / silicone resin (condensed compound conversion) at a weight ratio of 80/20 based on solid content, and further diluted with methanol so that the total solid content becomes 3%. A coating material composition (C) was prepared according to.

(Preparation Example 4 of coating material composition) 306 parts of methanol was added to 152 parts of tetramethoxysilane, 126 parts of water and 18 parts of 0.01N hydrochloric acid ("H ₂ O" / "OR" = 2. 0) was mixed, and this was mixed well using a disper. This mixture was stirred for 2 hours in a constant temperature bath at 25 ° C., and the weight average molecular weight was adjusted to 3500 to obtain a silicone resin (D).
The water contact angle of the cured film of the silicone resin (D) was measured in the same manner as in Preparation Example 1 and as a result, it was 4 °.

Next, a hollow silica IPA (isopropanol) dispersion sol (solid content 20%, average primary particle diameter of about 60 nm, outer shell thickness of about 15 nm) as a hollow silica fine particle component was added to the silicone resin (D) solution. Manufactured by MHI), and added hollow silica fine particles / silicone resin (condensed compound conversion) at a weight ratio of 80/20 based on solid content, and further diluted with methanol so that the total solid content becomes 3%. To prepare a coating material composition (D).

Preparation Example 5 of Coating Material Composition In the above Preparation Example 4, Zr was used as the organic zirconium component.
A coating material composition (E) was obtained by using (OC ₄ H ₉ ) ₃ (C ₅ H ₇ O ₂ ) and adding 1% to the coating material composition (D) with respect to the total solid content. It was

Preparation Example 6 of Coating Material Composition In the above Preparation Example 4, fine particles of visible light-responsive photocatalytic titanium oxide having a Ti—N bond (average particle size 20 nm) were added to the coating material composition (D) in a total solid state. A coating material composition (F) was obtained by adding 3% to the amount.

(Comparative Preparation Example 1 of coating material composition)
In Preparation Example 2, instead of the hollow silica fine particles, silica methanol sol (manufactured by Nissan Kagaku Kogyo "MA-S") was used as silica fine particles having no cavity formed inside the outer shell.
T ": average particle diameter 10 to 20 nm) except that the coating material composition (G) was prepared in the same manner as in Preparation Example 2.

(Comparative Preparation Example 2 of coating material composition)
Commercially available acrylic resin (Hitaroid 100 manufactured by Hitachi Chemical Co., Ltd.
7 "), hollow silica IP as a hollow silica fine particle component
A (isopropanol) dispersed sol (solid content 20%, average primary particle diameter about 60 nm, outer shell thickness about 15 nm: manufactured by Catalysts & Chemicals Industries, Ltd.) was used, and hollow silica fine particles / acrylic resin (condensation compound equivalent) was weighted on a solid content basis. A coating material composition (H) was prepared by adding such that the ratio was 80/20 and further diluting with methanol so that the total solid content was 3%.

(Examples 1-6, Comparative Examples 1-2) Thickness 17
Silicone UV-curing coating material (GE / Toshiba Silicone's "UVHC8" on a 5 μm PET film
556 ") is applied with a bar coater and then 3 at 120 ° C.
Heat treatment for 3 minutes, then UV irradiation to obtain a film thickness of 3
A hard coat layer having a thickness of μm was formed. The hard coat layer thus formed was subjected to a mechanical strength test using steel wool described later to confirm that it was not scratched.

Next, after corona discharge treatment was applied to the surface of the hard coat layer, the above Preparation Examples 1 to 6 and Comparative Preparation Example 1 were performed.
The coating material compositions (A) to (H) obtained in Nos. 1 to 2 are applied on the bird coat layer and heat-treated at 120 ° C. for 30 minutes to form a cured coating layer having a thickness of 100 nm. I got a film.

With respect to the antireflection film thus obtained, the total light transmittance, reflectance, haze ratio, refractive index, mechanical strength and fingerprint degradability were measured by the following test methods to evaluate the performance. .

(Total Light Transmittance) The total light transmittance at a wavelength of 550 nm was measured with a spectrophotometer (“U-3400” manufactured by Hitachi Ltd.).

(Reflectance) The back surface (bottom surface) of the antireflection film having a cured coating film is roughened with sandpaper, and a black matte lacquer coating is applied to this surface and dried, followed by a spectrophotometer (manufactured by Hitachi Ltd.). "U-3400") with wavelength 550
The reflectance in nm was measured.

(Haze ratio) A haze meter (“NDH2000” manufactured by Nippon Denshoku Industries Co., Ltd.) was used for measurement.

(Refractive index) After observing the fracture surface of the antireflection film with a scanning electron microscope and measuring the film thickness of the cured film, an ellipsometer ("EMS-1" manufactured by ULVAC)
The refractive index was derived with.

(Mechanical Strength) Steel wool # 0000 was reciprocated 10 times under a load of 100 g (speed 1
(cm / sec), and the mechanical strength was judged by the scratch generation level generated in the cured film. Then, it was evaluated that A: no scratch was generated, B: slight scratch was generated, C: scratch was generated, and D: many scratches were generated (whitening or peeling).

(Fingerprint-degrading property) 0.2 cc of oleic acid, which is a fingerprint component, was dropped on the surface of the cured film, and a white fluorescent lamp of 18 watts was irradiated with light at a distance of 30 cm, and a contact angle to water after 48 hours was reached. Degradability was judged by whether it was lower than that before irradiation, and evaluated as A: immeasurable, B: 10 ° or less, C: 10 to 20 °, D: 20 ° or more.

The results of each of the above tests are shown in Table 1. The PET film with the hard coat layer before forming the cured film had a total light transmittance of 90%, a luminous reflectance of 5.5%, and a haze ratio of 0.5.

[0095]

[Table 1]

As can be seen from Table 1, the antireflection film of each Example is superior in antireflection performance as compared with Comparative Example 1, and is superior in mechanical strength and antireflection performance as compared with Comparative Example 2. Met.

Further, in Example 2 in which only tetramethoxysilane was used as the matrix material, a cured coating layer excellent in mechanical strength was obtained as compared with Example 1 in which a trifunctional silicone resin was used in combination. Is confirmed.

In addition, it was confirmed that Example 2 using only tetramethoxysilane as the matrix material can obtain a cured coating layer excellent in mechanical strength as compared with Example 3 using only tetraethoxysilane. It

Further, Example 2 prepared by using only tetramethoxysilane as the matrix material in an average molecular weight within the range of 200 to 2000 was superior in mechanical strength to Example 4 having an average molecular weight of 3500. It is confirmed that a cured coating layer is obtained.

Further, in Example 5 in which the organic Zr was added, the mechanical strength of the cured film was excellent as compared with Example 4 in which the organic Zr was not added.

[0101]

As described above, the antireflection film according to claim 1 of the present invention comprises a partial hydrolyzate of a hydrolyzable organosilane and /
Alternatively, a cured coating layer of a coating material composition containing, as essential components, a silicone resin composed of a hydrolyzate and hollow silica fine particles having an average particle diameter of 5 nm to 2 μm and having voids formed inside the outer shell are provided. Therefore, the cured coating layer made of this silicone resin and the hollow silica fine particles has a low refractive index, and an antireflection layer formed of a single cured coating layer can provide an antireflection film having high antireflection performance. Is something that can be done.

Further, the invention of claim 2 is characterized in that, in claim 1, a hard coat layer having a hardness higher than that of the plastic film substrate is provided between the surface of the plastic film substrate and the cured coating layer of the coating material composition. Therefore, the hard coat layer can prevent the antireflection film from being scratched.

The invention of claim 3 is the antireflection film according to claim 1 or 2, wherein the surface of the cured coating layer of the coating material composition is provided with an antifouling layer having water and oil repellency. The antifouling layer can prevent dirt from getting on the fingerprints.

Further, the invention of claim 4 is the plastic film substrate according to any one of claims 1 to 3, wherein an adhesive layer is provided on the surface of the plastic film substrate opposite to the surface on which the cured coating layer of the coating material composition is provided. Since it is provided, the antireflection film can be used by sticking it to an arbitrary portion of the image display display with an adhesive layer.

According to the invention of claim 5, in any one of claims 1 to 4, the cured coating layer of the coating material composition has a layer thickness of 0.05 to 0.2 μm. It is possible to obtain high light reflection preventing performance.

Further, the invention of claim 6 is the silicone resin of the coating material composition according to any one of claims 1 to 5, wherein the silicone resin is a tetrafunctional hydrolyzable compound represented by SiX ₄ (X is a hydrolytic substituent). Since it is a tetrafunctional silicone resin composed of a partially hydrolyzed product and / or a hydrolyzed product of organosilane, a cured coating layer having high mechanical strength can be formed.

The invention according to claim 7 is the cured film having high mechanical strength according to claim 6, wherein the tetrafunctional hydrolyzable organosilane represented by SiX ₄ is tetramethoxysilane with X = OCH _3. A layer can be formed.

According to the invention of claim 8, in any one of claims 1 to 7, the silicone resin of the coating material composition is applied to the surface of a quartz glass substrate so as to have a film thickness of 100 nm. Since a cured film obtained by baking at a temperature of 10 ° C. having a contact angle with water droplets of 10 ° or less was used, even if the cured film was treated at a low temperature, an unreacted hydrolysis substituent did not remain, It is possible to obtain a cured coating layer having a low refractive index.

The invention of claim 9 is the silicone resin of any one of claims 1 to 8 having a weight average molecular weight of 200 to 2000.
Therefore, even if the proportion of hollow silica fine particles is increased and the proportion of silicone resin is decreased to lower the refractive index of the cured coating layer, the mechanical strength of the cured coating layer is reduced. It can be sufficiently secured.

The invention of claim 10 relates to claims 1 to 9.
In any one of the above, as a silicone resin of the coating material composition, a tetrafunctional organoalkoxysilane represented by SiX ₄ (X = OR, R is a monovalent hydrocarbon group) is used in a molar ratio [H ₂ O] / [ Since the partial hydrolysis product and / or the hydrolysis product obtained by the hydrolysis reaction in the presence of water having an OR] of 1.0 or more and in the presence of an acid or an alkali catalyst are used, the silicone resin The unreacted hydrolyzable substituent can be reduced, and a cured film layer having a low refractive index can be formed.

A display device according to claim 11 of the present invention is one in which the antireflection film according to any one of claims 1 to 10 is attached to the surface of the display surface of an image display display, By preventing the reflection of light with an antireflection film, a clear image can be displayed.

According to a twelfth aspect of the present invention, the display device according to any one of the first to the first aspects is provided on at least one surface of a front plate disposed on the front side of the image display.
The antireflection film according to any one of 0 is attached, and reflection of ambient light is prevented by the antireflection film,
It is possible to display a clear image.

[Brief description of drawings]

FIG. 1 shows an antireflection film according to the present invention, and (a), (b), and (c) are schematic views showing an example of an embodiment, respectively.

FIG. 2 shows a display device according to the present invention, and (a) and (b) are schematic diagrams showing an example of an embodiment, respectively.

[Explanation of symbols]

1 plastic film substrate 2 cured film 3 Antireflection layer 4 Hard coat layer 5 Antifouling layer 6 Adhesive layer 7 image display 8 Display surface 9 Front plate

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C09D 183/02 C09D 183/04 183/04 C09J 7/02 Z C09J 7/02 G02B 1/10 A (72 ) Inventor Toru Tatebayashi 1048 Kadoma, Kadoma-shi, Osaka Prefecture Matsushita Electric Works Co., Ltd. F-term within the company (reference) BA10B BA10D DE04B EH46 EH462 EJ42 EJ422 EJ55 EJ552 GB41 JB05D JB06D JB12B JK12C JL06D JM01B JM02C JN06 YY00B 4J004 AA06 AA08 AA09 AA10 AB08 PCA19 PA0821A446 AB02 CA446A20 AB02 PA446B20191911

Claims (12)

[Claims] 1. A silicone resin comprising a partial hydrolyzate of a hydrolyzable organosilane and / or a hydrolyzate on the surface of a plastic film substrate, and an average particle diameter of 5
An antireflection film comprising a cured coating layer of a coating material composition, which has an essential component of hollow silica fine particles having a diameter of nm to 2 μm and in which a cavity is formed inside an outer shell. 2. A hard coat layer having a hardness higher than that of the plastic film substrate is provided between the surface of the plastic film substrate and the cured coating layer of the coating material composition. The antireflection film described. 3. The antireflection film according to claim 1, wherein the surface of the cured coating layer of the coating material composition is provided with an antifouling layer having water and oil repellency. 4. A pressure-sensitive adhesive layer is provided on the surface of the plastic film substrate opposite to the surface on which the cured coating layer of the coating material composition is provided, according to any one of claims 1 to 3. The antireflection film described in. 5. The antireflection film according to claim 1, wherein the cured coating layer of the coating material composition has a layer thickness of 0.05 to 0.2 μm. 6. The silicone resin of the coating material composition comprises a partial hydrolyzate and / or hydrolyzate of a tetrafunctional hydrolyzable organosilane represented by SiX ₄ (X is a hydrolyzable substituent). It is a functional silicone resin, The antireflection film in any one of Claim 1 thru | or 5 characterized by the above-mentioned. 7. The antireflection film according to claim 6, wherein the tetrafunctional hydrolyzable organosilane represented by SiX ₄ is tetramethoxysilane having X═OCH ₃ . 8. A silicone resin for the coating material composition, which is formed on the surface of a quartz glass substrate to a film thickness of 10
8. A cured coating film obtained by coating so as to have a thickness of 0 nm and baking at 100 ° C., which has a surface water droplet contact angle of 10 ° or less, is used. Anti-reflection film. 9. The antireflection film according to claim 1, wherein a silicone resin having a weight average molecular weight of 200 to 2000 is used as the silicone resin of the coating material composition. . 10. A tetrafunctional organoalkoxysilane represented by SiX ₄ (X = OR, R is a monovalent hydrocarbon group) is used as a silicone resin for the coating material composition in a molar ratio [H ₂ O] / [. OR] is 1.0 or more, and a partial hydrolyzate and / or a hydrolyzate obtained by a hydrolysis reaction in the presence of an acid or alkali catalyst are used. Item 10. The antireflection film according to any one of items 1 to 9. 11. A display device, wherein the antireflection film according to any one of claims 1 to 10 is attached to a surface of a display surface of an image display display. 12. The method according to claim 1, wherein at least one surface of a front plate disposed on the front side of the image display is provided.
11. A display device, to which the antireflection film according to any one of items 1 to 10 is attached.