JP2000160098A - Coating solution, optical functional film, and antireflfction film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare a coating solution which can efficiently produce a high- quality thin functional film excellent in adhesion to a substrate and provide an optical functional film and an antireflection film. SOLUTION: This coating solution contains, as the main ingredient, a silicate oligomer which is obtained by mixing an alkyl silicate (A) represented by the formula: RaO[- Si(ORb)2}-O-]n-Ra (wherein Ra and Rb are each an alkyl; and (n) is an integer of 1 or higher) with a silicon alkoxide (B) represented by the formula: RcSi(ORd)3 (wherein Rc is an alkyl, phenyl, vinyl, or the like; and Rd is an alkyl) and subjecting the resultant mixture to hydrolysis and polycondensation in the presence of water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an ultraviolet shielding effect,
The present invention relates to various functional coating films having a heat ray reflection effect, an antireflection effect, etc., an antireflection film, and a coating solution for producing them by coating.

[0002]

2. Description of the Related Art Conventionally, an ultraviolet blocking effect, a heat ray reflecting effect,
Methods for forming a functional thin film having an antireflection effect and the like are generally roughly classified into a vapor phase method and a coating method. Methods for producing a functional thin film by a gas phase method include a physical method such as a vacuum evaporation method and a sputtering method, and a chemical method such as a CVD method. Examples of the method for producing a functional thin film by a coating method include a spray method, a dipping method, and a screen printing method.

The method for producing a functional thin film by the vapor phase method can obtain a high-performance and high-quality thin film, but it requires a precise control of the atmosphere in a high vacuum system, and has a special problem. However, there is a problem that a complicated heating device or an ion generation accelerating device is required, and the manufacturing cost is inevitably increased because the manufacturing device is complicated and large. Further, the method for producing a functional thin film by the vapor phase method has a problem that it is difficult to increase the area of the thin film or to produce a thin film having a complicated shape.

On the other hand, among the methods for producing a functional thin film by a coating method, those using a spray method have problems such as poor use efficiency of a coating solution and difficulty in controlling film forming conditions. In addition, among the methods for producing a functional thin film using a coating method, those using a dipping method, a screen printing method, and the like have good utilization efficiency of a film forming material and have advantages in mass production and equipment cost, In general, functional thin films obtained by the coating method
There is a problem that the function and quality are inferior to the thin film obtained by the gas phase method.

[0005]

In recent years, as a method of obtaining a thin film of excellent quality by a coating method, a dispersion in which inorganic or organic ultrafine particles are dispersed in an acidic or alkaline aqueous solution is coated on a substrate and fired. A way to do that has been proposed.
This manufacturing method is advantageous in terms of mass production and equipment costs, but requires a high-temperature baking process during the manufacturing process, which makes it impossible to form a film on a plastic base material. That the uniformity of the obtained thin film is not enough due to the difference in the degree of shrinkage between the film and the coating film, the problem that the performance is still inferior when compared to the thin film obtained by the gas phase method, (For example, several tens of minutes or more), and there is a problem that productivity is poor.

[0006] In response to the above problems, the present inventors have proposed R _m S
i (OR ′) _n [R is an alkyl group having 1 to 10 carbon atoms, or a reactive group such as a vinyl group, a (meth) acryloyl group, an epoxy group, an amide group, a sulfonyl group, a hydroxyl group, and a carboxyl group; Represents an alkyl group having 1 to 10 carbon atoms, m
+ N is an integer of 4], and silica gel prepared by hydrolyzing a silicon alkoxide represented by the following formula is coated directly or via another layer on a transparent resin base material, and the formed coating layer is applied to the base material. Patent application for a method of efficiently producing a desired high-quality functional thin film without damaging the substrate by heating to the extent that does not damage or irradiating with active energy rays to form a gel layer However, the silica sol obtained by an ordinary method has a problem in practical use because the gel film has a weak adhesion to the base material and thus easily peels off from the base material.

[0007] The present invention has been made in view of the above problems, and an object of the present invention is to provide a method employing a coating method.
A coating solution capable of efficiently producing a desired high-quality functional thin film without damaging the base material and having good adhesion to the base material, and an optical functional film manufactured using the solution. And an antireflection film.

[0008]

The above object is achieved by the present invention described below.

That is, the coating solution of the present invention comprises an alkyl silicate represented by the following formula as a component (A) and a silicon alkoxide represented by the following formula as a component (B):
The amount of C atoms in R _c in the component (B) is 0.04 per mole of Si atoms in the sum of the components (A) and (B).
Mixed in the range of ~ 0.4 mol and hydrolyzed in the presence of water,
It is characterized by mainly comprising a silicate oligomer obtained by condensation polymerization. : (A) component: R _a O _{[- {Si (OR b) 2} } -O
-] An alkyl silicate represented by _n- R _a (R _a and R _b may be the same or different and represent an alkyl group having 1 to 10 carbon atoms, and n is an integer of 1 or more); Component (B): R _c Si (OR _d ) ₃ (R _c is an alkyl group having 1 to 10 carbon atoms, a phenyl group, a vinyl group, a (meth) acryloyl group, an epoxy group,
R _d represents an alkyl group having 1 to 10 carbon atoms, such as an amide group, a mercapto group, an isocyanate group, a sulfonyl group, and a carboxyl group).

[0010] The optical functional film of the present invention is formed by applying and drying the coating solution of the present invention directly on a substrate or via another layer, and directly or on another layer of the substrate. 1.38 to 1.46 supported through
Characterized in that it is an optically functional film.

Further, the antireflection film of the present invention has a hard coat layer formed directly or through another layer on the surface of a base film, and has a refractive index of 1 directly or through another layer. A high-refractive-index layer having a refractive index of 1.38 or more and a low-refractive-index layer having a refractive index of 1.38 to 1.46 by coating and drying the coating solution of the present invention. It is characterized by.

The ultraviolet shielding film of the present invention is an ultraviolet shielding film supported on a base material directly or through another layer, and is provided with the coating solution of the present invention.
A low refractive index layer having a refractive index of 1.38 to 1.46 is formed by drying, and a high refractive index layer having a refractive index of 1.7 or more is formed thereon.

Further, the heat ray reflective film of the present invention is provided on a substrate.
A low-refractive-index layer having a refractive index of 1.38 to 1.46 by applying and drying the coating solution of the present invention, which is a heat ray reflective film supported directly or via another layer; It is characterized by being obtained by forming a high refractive index layer having a refractive index of 1.7 or more thereon.

[0014]

Next, the present invention will be described in more detail with reference to preferred embodiments.

According to the present invention, there is provided a method of applying and drying a coating solution having a special composition of the present invention on a substrate on which an optical functional film is supported, particularly on a transparent substrate, directly or via another layer. Thus, an optical functional film having various optical functional characteristics can be obtained. Optical functional films formed by the coating solution of the present invention include, for example, various displays such as word processors, computers, and televisions, surfaces of polarizing plates used for liquid crystal display elements, sunglass lenses, prescription eyeglass lenses, camera finder lenses, and the like. Required for optical lenses, cover of various instruments, window glass of automobiles, trains, etc., for example, anti-reflection function, ultraviolet blocking function,
It is useful for the purpose of providing a heat ray reflection function.

(A) in the coating solution of the present invention
The component is an alkyl silicate represented by the following formula (1): R _a O [-{Si (OR _b ) ₂ } -O-] _n -R _a where R _a and R _b Is an alkyl group having 1 to 10 carbon atoms, which may be the same or different, and n is an integer of 1 or more. The component (A) is specifically a methyl silicate in which _Ra and _Rb are methyl groups, for example, MS51 (trade name, manufactured by Mitsubishi Chemical Corporation),
MS56 (trade name, manufactured by Mitsubishi Chemical Corporation) can be used.
_a and R _b are ethyl silicates of an ethyl group, n is 1, tetramethoxysilane, tetraethoxysilane, tetra-
iso-propoxysilane, tetra-n-propoxysilane, tetra-n-butoxysilane, tetra-sec-
Butoxysilane, tetra-tert-butoxysilane,
Tetrapentaethoxysilane, tetrapenta-iso-
Propoxysilane, tetrapenta-n-propoxysilane, tetrapenta-n-butoxysilane, tetrapenta-sec-butoxysilane, tetrapenta-tert-
Butoxysilane and the like can be used.

(B) in the coating solution of the present invention
The component is a silicon alkoxide represented by the following formula (2): R _c Si (OR _d ) ₃ formula (2), wherein R _c is an alkyl group having 1 to 10 carbon atoms, a vinyl group, or a phenyl group. ,
(Meth) acryloyl group, an epoxy group, an amide group, a mercapto group, an isocyanate group, a sulfonyl group, a carboxyl group, the R _d represents an alkyl group having 1 to 10 carbon atoms.
More specifically, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, methyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethylethoxysilane, dimethylethoxysilane Methoxysilane, dimethylpropoxysilane, dimethylbutoxysilane, methyldimethoxysilane, methyldiethoxysilane, hexyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, 3 -(2-aminoethylaminopropyl) trimethoxysilane and the like.

The mixing ratio of the components (A) and (B) is
The amount of C atoms in R _c in the component (B) is 0.04 per mole of Si atoms in the sum of the components (A) and (B).
It was mixed in the range of ~ 0.4 mol.

The component (A) is mainly involved in the adhesion of the film.
And component (B) is the stability of coating solution and low refractive index
It is mainly involved in sex. In the components (A) and (B),
-OR _a,-OR_b,-OR_dFunctional groups are hydrolyzed
But R in component (B)_cIs not a hydrolyzable group
And remains in the film even after coating and drying of the coating solution. That
Because of this R_cThe properties of the coating film vary depending on the amount of C atoms in the coating
I found something. Coating solution and function of the present invention
R per mole of Si atom in the conductive film_cC field inside
The amount of C is less than 0.04 mol to 0.4 mol.
When there are many particles, the strength of the obtained optical functional film is weak.
On the other hand, on the other hand, C atoms
If the refractive index is small, the optical characteristics such as the refractive index will increase.
It becomes.

Such a compounding ratio is obtained by mixing the component (A) with the component (B).
In terms of the weight ratio of the solid content to the components, approximately 50:50 to 9
This corresponds to a range of 5: 5. That is, when the component (A) is more than the above range, the solution after hydrolysis becomes cloudy and a uniform transparent film cannot be obtained, and when the component (A) is less than the above range, repelling or the like occurs. Causes a failure of the coating film.

The hydrolysis of the alkyl silicate as the component (A) and the silicon alkoxide as the component (B)
Preferably, the component (A) and the component (B) are dissolved in a suitable organic solvent and the reaction is performed in the presence of water. The components (A) and (B) are dissolved and diluted with an organic solvent, so that they come into uniform contact with water and have the advantage of performing uniform hydrolysis.

Examples of the organic solvent used in the hydrolysis include alcohols such as methyl ethyl ketone, isopropyl alcohol, methanol, ethanol, methyl isobutyl ketone, ethyl acetate and butyl acetate, ketones, and the like.
Examples thereof include esters, halogenated hydrocarbons, aromatic hydrocarbons such as toluene and xylene, and mixtures thereof.

Generally speaking, when a ketone is used, the hydrolysis reaction tends to proceed rapidly, while when an alcohol is used, the hydrolysis reaction tends to be slow. Therefore, the reaction rate can be controlled by appropriately combining the types of the organic solvents.

The amounts of the components (A) and (B) added to the coating solution are determined as follows: the components (A) and (B) are 100% hydrolyzed and condensed in the presence of water. The silicate oligomer is dissolved so as to have a solid content of 0.05% or more, preferably 0.1 to 30% by weight. If the concentration of the silicate oligomer in the coating solution is less than 0.05% by weight, the formed functional film cannot sufficiently exhibit the desired properties, while if it exceeds 30% by weight, it is difficult to form a transparent homogeneous film. Become. In the present invention, an organic or inorganic binder can be used in combination as long as the solid content is within the above range.

A solution containing the components (A) and (B), an organic solvent and water in an amount not less than the amount required for hydrolysis is 15 to 35.
° C., preferably at a temperature of 22 to 28 ° C., for 2 to 30 hours,
The coating solution is produced by preferably stirring for 3 to 10 hours.

Alternatively, when the components (A) and (B) are hydrolyzed without using an organic solvent, uniform hydrolysis can be performed by stirring in water.

In the above-mentioned hydrolysis, it is preferable to use a catalyst, and as such a catalyst, an acid such as hydrochloric acid, nitric acid, sulfuric acid or acetic acid is preferable.
It is added as an aqueous solution of 1 to 20.0N, preferably about 0.005 to 5.0N, and the water in the aqueous solution can be used as the water for hydrolysis.

The amount of Si-OH in the silicate oligomer obtained by carrying out the hydrolysis / condensation reaction according to the above procedure is preferably in the range of 1.2 to 2.2 mol per mol of Si atom. When the amount of Si-OH is larger than this range, there are problems such as poor storage stability of the solution. If the amount of Si-OH is smaller than this range, there is a problem that the adhesion to the base material is lost. Si-OH content is
For example, it can be determined from the occupied area of the peak derived from Si-OH by performing NMR measurement. Also, if the initial amount of added water is known and the change over time in the amount of water and the amount of alcohol due to the alkoxy group is measured using near-infrared spectroscopy, infrared spectroscopy, Karl Fischer method, etc. Indirectly, the amount of Si-OH can be determined.

The average molecular weight of the silicate oligomer obtained by performing the hydrolysis / condensation reaction according to the above procedure is 30.
It is preferably in the range of 0 to 100,000. When the average molecular weight is smaller than this amount, there are problems such as insufficient strength of the film after coating and drying. Further, when the average molecular weight is larger than this range, there is a problem that the adhesion to the substrate is lost. The molecular weight is obtained, for example, by GPC measurement under the following conditions, and based on the obtained retention time, is obtained as a polystyrene size-converted molecular weight obtained from the relationship between the known retention time and the molecular weight of polystyrene.

Separation columns: The following three types of polystyrene gel-filled columns (manufactured by Tosoh Corporation) are used by sequentially connecting three columns.

“TSK GEL G-1000H” “TSK GEL G-2000H” “TSK GEL G-4000H” Effluent: tetrahydrofuran (1 ml / min) Outflow temperature: 40 ° C.

Originally, the retention time is determined by the size (dimension) of the molecule.
It has no direct relation to the molecular weight. However, the molecular weight and the molecular size are almost proportional in the same system molecular structure. On the other hand, the relationship between the molecular weight and the retention time of the novel polymer is not clear. Therefore, in the present invention, in order to define the molecular weight of the novel silicate oligomer, the molecular weight in terms of polystyrene is adopted. From the viewpoint of the optical properties and the pot life of the liquid, the ratio of the tetrafunctional silicon alkoxide to the other alkoxide is preferably in the range of 30:70 to 95: 5.

Various additives can be added to the coating solution of the present invention. The most important additives include curing agents that promote film formation, and examples of these curing agents include organic acid solutions of organic acid metal salts such as sodium acetate and lithium acetate, such as acetic acid and formic acid. The concentration of the organic acid metal salt is about 1 to 20% by weight, and the amount of the organic acid metal salt in the coating solution is based on 100 parts by weight of the silicate oligomer present in the coating solution. The range of about 0.1 to 10 parts by weight as the metal salt is preferable.

The transparent resin substrate used in the present invention includes:
For example, acetate butyrate cellulose film, polyether sulfone film, polyacrylic resin film, polyurethane resin film, polyester film, polycarbonate film, polysulfone film, polyether film, trimethylpentene film, polyetherketone film, (meta) An acrylonitrile film or the like can be used, but a uniaxially stretched polyester film is particularly preferably used because of its excellent transparency. Usually, a thickness of about 5 μm to 1000 μm is suitably used.

In the present invention, a coating solution mainly comprising the silicate oligomer is applied to the surface of the substrate, preferably a transparent resin substrate, by a coating method,
Thereafter, the coated material is heated or irradiated with an active energy ray to form a silica gel film.

As a method for applying the coating solution of the present invention to a substrate, spin coating, dipping, spraying, bar coating, die coating, slide coating,
A roll coating method, a meniscus coating method, a flexographic printing method, a screen printing method, a bead coating method and the like can be mentioned.

The curing by heating is performed at 150 ° C. or less, more preferably at 120 ° C. in consideration of damage to the substrate.
It is desirable that:

Examples of the active energy beam include an electron beam and an ultraviolet ray, and an electron beam is particularly preferable. For example, in the case of electron beam curing, 50 to 1 emitted from various electron beam accelerators such as Cockloft-Walton type, Bande graph type, Resonant transformation type, Insulating core transformer type, Linear type, Dynamitron type, High frequency type, etc. 000 KeV, preferably 100-30
An electron beam having an energy of 0 KeV is used. In the case of ultraviolet curing, ultraviolet rays emitted from a light source such as an ultra-high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a xenon arc, and a metal halide lamp are used. When the active energy beam is an electron beam, the total irradiation amount of the active energy beam is 2 Mrad or more, preferably 2 to 50 Mrad.
The range of Mrad is desirable.

The electron beam irradiation is preferably performed while replacing air with oxygen or in a sufficient oxygen atmosphere.
By performing the reaction in an oxygen atmosphere, generation of Si—O—Si bond, polymerization and condensation are promoted, and a more uniform and high-quality gel layer can be formed.

As described above, in the method for producing an optical functional film of the present invention, an optical functional film having a desired function can be obtained by selecting a coating material to be used. The optical functional film obtained by the present invention can be used as a single-layer antireflection film or as a low refractive index layer in a multilayer antireflection film.

An antireflection film can be formed by alternately laminating a high refractive index film and a low refractive index film on a substrate, preferably a transparent substrate. The greater the number of high-refractive-index films and low-refractive-index films, the higher the reflectance at the set wavelength.
However, as the number of layers increases, defects such as pinholes are more likely to occur, and the number of coatings increases, which is undesirable in terms of cost.

In order to increase the antireflection efficiency in a wavelength region having a center wavelength of about 550 nm, the layer structure includes
It is preferable to provide a high refractive index layer and a low refractive index layer on a substrate.

The high refractive index material preferably has a refractive index of 1.65 or more in order to increase the antireflection efficiency in a wavelength region having a center wavelength of about 550 nm. Compositions for forming a high refractive index film include titanium oxide, cerium oxide, zirconium oxide, zinc oxide, bismuth oxide,
TO, ATO, a mixture thereof and the like can be mentioned.

The high-refractive-index film can be formed by a vacuum technique such as a vapor deposition method, a sputtering method, or a CVD method, and can be formed by a spin coating method, a dip method, a spray method, a bar coating method, or the like. Formation by various printing methods such as a die coating method, a slide coating method, a roll coating method, a meniscus coating method, a flexographic printing method, a screen printing method, and a bead coating method is also possible.

Further, in order to increase the mechanical strength of the antireflection film, it is preferable to provide a hard coat layer between the substrate and the high refractive index layer. Alternatively, a high refractive index hard coat layer in which the high refractive index layer has a hard coat property may be provided between the substrate and the low refractive index layer.

The optical functional film obtained by the present invention can be used as a low refractive index layer in a heat ray reflective film. As disclosed in JP-A-10-236847, a heat ray reflective film can be formed by alternately laminating high refractive index layers and low refractive index layers on a transparent substrate. The high refractive index material preferably has a refractive index of 1.7 or more in order to increase the reflection efficiency in the heat ray (infrared) wavelength region.

As the high refractive index layer in the heat ray reflective film, the same one as in the case of the antireflection film can be used, and it can be formed by the same manufacturing method as in the case of the antireflection film.

The number of layers is preferably an odd number in order to increase the reflection efficiency at the center wavelength of heat rays (infrared rays). Further, for the same reason as in the case of the antireflection film, it is preferable that the number of layers is small. As a preferred layer configuration, on the substrate,
It is preferable to form a high refractive index layer, a low refractive index layer, and a high refractive index layer in this order.

Further, the optically functional film obtained by the present invention can be used as a low refractive index layer in an ultraviolet blocking film. The ultraviolet ray blocking film has the same layer configuration as the above-mentioned heat ray reflective film, and in particular, the high refractive index layer is made of a material having an ultraviolet absorbing ability. In this case, the constituent materials of the high refractive index layer include titanium oxide, cerium oxide, zinc oxide, bismuth oxide, and a mixture thereof.

[0050]

The optical functional film of the present invention will be described below with reference to examples. In the following examples, the molecular weight of the coating composition was determined by performing the GPC measurement described above. Further, the amount of Si-OH was determined by NMR measurement and the occupied area of the peak derived from Si-OH.

Example 1 Preparation of Coating Composition for Forming Low Refractive Index Layer MS51 (trade name, manufactured by Mitsubishi Chemical Corporation) (component (A)) and methyltrimethoxysilane (manufactured by Tokyo Chemical Industry Co., Ltd.) B) component) at a solid content weight ratio of 60: 4
0 and mixed. Add methyl ethyl ketone and 0.005
N hydrochloric acid was added, and the mixture was prepared so that the total solid content was 6 wt% and the water concentration was 5 wt%. This was stirred at 25 ° C. for 3 hours to perform hydrolysis and polycondensation. After adding a mixture of sodium acetate and acetic acid as a curing agent, the mixture was diluted with isopropanol to a solid content of 1 wt% to prepare a silicate oligomer coating solution. The average molecular weight at that time was 30,000. Also, Si-OH
The amount was 1.8 mol times with respect to the contained Si.

Formation of High Refractive Index Hard Coat Layer A PET film (A-4350: trade name, manufactured by Toyobo Co., Ltd.) having a thickness of 100 μm was prepared as a transparent base film. On the other hand, ZrO ₂ ultrafine particles having a refractive index of 1.9 (No. 1275)
A: Trade name, manufactured by Sumitomo Osaka Cement) and ionizing radiation-curable resin (X-12-2400-6: trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed at a weight ratio of 2: 1. The obtained resin composition was applied on a PET film by gravure reverse coating so as to have a thickness of 7 μm / dry, and the solvent was removed by drying. Thereafter, the coating was cured by irradiating 5 Mrad with an electron beam at 175 kV to form a high refractive index hard coat layer.

Preparation of Low Refractive Index Layer On the high refractive index hard coat layer obtained in the above step,
Further, the silicate oligomer coating solution obtained in the above step was applied so as to have a thickness of 0.1 μm. The obtained coating film was cured at 120 ° C. for 1 hour to obtain an antireflection film.

Evaluation of Characteristics of Antireflection Film The optical characteristics of the antireflection film obtained through the above steps (1) and (2) were such that the total light transmittance was 94.0%, the haze value was 0.5,
The minimum reflectance in the wavelength region of visible light is 1.5,
The antireflection performance was excellent. The adhesion by the tape peeling test was 100 (100)%, and the adhesion to the substrate was also good.

Example 2 The same process as in Example 1 was carried out except that the mixing ratio of the component (A) and the component (B) was 90:10 in terms of solids weight ratio. An antireflection film was obtained. The optical properties of the obtained antireflection film are such that the total light transmittance is 94.0%, the haze value is 0.5, and the minimum reflectance in the visible light wavelength region is 1.2, and the antireflection performance is excellent. Was. The adhesion by the tape peeling test was 100 (100)%, and the adhesion to the substrate was also good.

[Embodiment 3] (B) in the embodiment 1
An antireflection film was obtained in the same process as in Example 1 except that the component was changed to methyltriethoxysilane. The optical properties of the obtained antireflection film are such that the total light transmittance is 94.0%, the haze value is 0.5, and the minimum reflectance in the visible light wavelength region is 1.4, and the antireflection performance is excellent. Was. The adhesion by the tape peeling test is 1
It was 00 (100)%, and the adhesion to the substrate was good.

[Embodiment 4] (B) of Embodiment 2
An antireflection film was obtained in the same process as in Example 2 except that the component was changed to methyltriethoxysilane. The optical properties of the obtained antireflection film are such that the total light transmittance is 94.0%, the haze value is 0.5, and the minimum reflectance in the visible light wavelength region is 1.2, and the antireflection performance is excellent. Was. The adhesion by the tape peeling test is 1
It was 00 (100)%, and the adhesion to the substrate was good.

Example 5 Preparation of heat ray reflective film: 100 mm thick as transparent substrate film
A μm PET film (A-4350: trade name, manufactured by Toyobo) was used. On the other hand, ZrO ₂ ultrafine particles having a refractive index of 1.9 (No. 1275A: trade name, manufactured by Sumitomo Osaka Cement) and ionizing radiation-curable resin (X-12-2400-6: trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) were weighed. The mixture was mixed at a ratio of 2: 1. The obtained resin composition was coated on a PET film to a thickness of about 0.1.
Coating was performed to a thickness of μm, and the solvent was removed by drying. Thereafter, the coating film was cured by irradiating 5 Mrad with an electron beam at 175 kV to form a first high refractive index layer. The same silicate oligomer coating solution as used in Example 1 was applied thereon so as to have a thickness of 0.15 μm. The obtained coating film was heat-treated at 120 ° C. for 1 hour to form a second low refractive index layer. Further, a heat ray reflective film was obtained by providing a third high refractive index layer thereon similarly to the first high refractive index layer.

The optical characteristics of the obtained heat ray reflective film were such that the visible light transmittance was 80.0% and the sunlight transmittance was 44.5%, and the heat ray reflection performance was excellent. The adhesion by the tape peeling test was 100 (100)%, and the adhesion to the substrate was also good.

[Example 6] Preparation of ultraviolet blocking film: thickness 10 as transparent substrate film
A 0 μm PET film (A-4350: trade name, manufactured by Toyobo) was used. On the other hand, a titanium oxide film having a refractive index of 2.1 was formed by a sputtering method to form a first high refractive index layer. The same silicate oligomer coating solution as used in Example 1 was applied thereon so as to have a thickness of 0.15 μm. The obtained coating film was subjected to a heat treatment at 120 ° C. for 1 hour to form a low refractive index layer. Further, a third high-refractive-index layer was provided thereon similarly to the first high-refractive-index layer to obtain an ultraviolet-ray shielding film. As for the optical characteristics of the obtained ultraviolet ray blocking film, the ultraviolet ray transmittance was 9.3%, and the ultraviolet ray blocking performance was excellent. The adhesion by the tape peeling test was 100 (1).
00)%, and the adhesion to the substrate was also good.

Comparative Example 1 A coating solution was obtained under the same reaction conditions, except that the same material as in Example 1 was used and MS51 was not added. This sol solution was applied on the high refractive index hard coat layer prepared in Example 1 so as to have a thickness of 0.1 μm, and heat-treated at 120 ° C. for 1 hour to obtain an antireflection film. The optical characteristics of this antireflection film are as follows: total light transmittance 94.0.
%, A haze value of 0.5, and a minimum reflectance in a visible light wavelength region of 1.2, which showed antireflection performance equivalent to that of Example 1 above. Partial peeling of the film was observed.

Comparative Example 2 A coating solution was obtained under the same reaction conditions, except that the same material as in Example 1 was used and MS51 was not added. This sol solution was subjected to the same steps as in Example 5 to obtain a heat ray reflective film. Regarding the optical characteristics of the obtained heat ray reflective film, the visible light transmittance was 79.0.
%, And a solar light transmittance of 50.9%, the same heat ray reflection performance as in Example 5 was shown. However, in the adhesion by the tape peeling test, partial peeling of the coating film was observed.

Comparative Example 3 A coating solution was obtained under the same reaction conditions, except that the same material as in Example 1 was used and MS51 was not added. This sol solution was subjected to the same process as in Example 6 to obtain an ultraviolet shielding film. The optical characteristics of the obtained ultraviolet blocking film are such that the ultraviolet transmittance is 11.
At 3%, the same ultraviolet ray blocking performance as in Example 6 was shown, but partial peeling of the coating film was observed in the adhesion by the tape peeling test.

[0064]

As described above, according to the coating solution, the optically functional film and the antireflection film of the present invention, the optically functional film and the optically functional film formed by using the coating solution of the present invention can be used even in a method employing a coating method. The antireflection film can efficiently produce a desired high-quality functional film without damaging the base material, and has good adhesion to the base material.

Continued on the front page (72) Inventor Toshio Yoshihara 1-1-1, Ichigaya-Kaga-cho, Shinjuku-ku, Tokyo F-term in Dai Nippon Printing Co., Ltd. (reference) 4D075 CB07 DA04 EB43 4J038 DL021 GA01 GA03 GA06 GA07 GA09 GA11 GA13 MA09 MA14 NA19 PA07 PB08 PC08

Claims (9)

[Claims] An alkyl silicate represented by the following formula is defined as a component (A), a silicon alkoxide represented by the following formula is defined as a component (B), and the amount of C atoms in R _c in the component (B) is The silicate oligomer obtained by mixing the components (A) and (B) in a range of 0.04 to 0.4 mol per mol of Si atom of the total and hydrolyzing and condensation polymerizing in the presence of water is mainly used. the coating solution is characterized by comprising as: (a) component: R _a O _{[- {Si (OR b) 2} } -O
-] An alkyl silicate represented by _n- R _a (R _a and R _b may be the same or different and represent an alkyl group having 1 to 10 carbon atoms, and n is an integer of 1 or more); Component (B): R _c Si (OR _d ) ₃ (R _c is an alkyl group having 1 to 10 carbon atoms, a phenyl group, a vinyl group, a (meth) acryloyl group, an epoxy group,
An amide group, a mercapto group, an isocyanate group, a sulfonyl group, a carboxyl group, and R _d represents an alkyl group having 1 to 10 carbon atoms). 2. The coating solution according to claim 1, wherein the hydrolysis and the polycondensation are performed in the presence of water and an organic solvent. 3. The method according to claim 1, wherein the amount of Si—OH is in the range of 1.2 to 2.2 mol per mol of Si atom, and the main component is a silicate oligomer having an average molecular weight of 300 to 100,000. 3. The coating solution according to 1 or 2. 4. The method according to claim 1, wherein R _a and R _{b of the} component (A) are a methyl group and / or an ethyl group, and R _{c of the} component (B) is a methyl group. Coating solution. 5. The coating solution according to claim 1, wherein the solid content is 0.05 to 30% by weight. 6. An optical functional film supported on a substrate directly or via another layer, wherein the coating solution according to claim 1, 2, 3, 4 or 5 is applied and dried. 1.38, formed by
The optical functional film of -1.46. 7. A hard coat layer is formed directly or via another layer on the surface of a base film, and a high refractive index layer having a refractive index of 1.65 or more is formed directly or via another layer on the hard coat layer. A coating solution according to claim 1, 2, 3, 4, or 5 is formed thereon, and then dried by applying and drying the coating solution.
An antireflection coating film obtained by forming a low refractive index layer of from 1.46 to 1.46. 8. An ultraviolet blocking film supported on a substrate directly or via another layer, wherein the coating solution according to claim 1, 2, 3, 4 or 5 is applied and dried. A low refractive index layer having a refractive index of 1.38 to 1.46, and a high refractive index layer having a refractive index of 1.7 or more formed thereon. 9. A heat ray reflective film supported on a substrate directly or via another layer, wherein the coating solution according to claim 1, 2, 3, 4 or 5 is applied and dried. A heat-reflection film obtained by forming a low-refractive-index layer having a refractive index of 1.38 to 1.46, and forming a high-refractive-index layer having a refractive index of 1.7 or more thereon.