JP2003041152A - Complex, coating composition, coating film thereof, reflection-preventing film, reflection-preventing film and image display apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain titanium oxide uniformly dispersible even without using a dispersant, a coating material which is mixed with the titanium oxide and is capable of forming a high-quality thin film having an adjusted refractive index, a coating film formed by using the coating material, a reflection preventing film using the coating film and a reflection preventing film to which the reflection preventing film is applied and to provide an image display apparatus. SOLUTION: This coating composition comprises (1) a rutile type titanium oxide having 0.01-0.1 μm primary particle diameter and the surface which is coated with an inorganic compound to lower or eliminate photocatalytic activity catalyst and to which a polymer is bonded by covalent bond, (2) a binder component and (3) an organic solvent. This coating film obtained by using the coating composition is suitable for forming a light transmission layer constituting a single-layer type or multilayer type reflection preventing film 17, especially a layer 18 having a medium refractive index.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a coating composition having excellent dispersibility, dispersion stability, and coating suitability, a material to be added to the coating composition, a coating film formed by using the coating composition, and , A functional thin film using the coating film.

The present invention is particularly preferably applied to a layer constituting an antireflection film for covering a display surface of an LCD, a CRT or the like, particularly a medium to medium layer.
High refractive index layer, high refractive index hard coat layer, a coating composition suitable for forming an optical thin film such as a conductive transparent thin film, an antireflection film having a layer of an optical thin film formed using the coating composition, And an antireflection film to which such an antireflection film is applied.

[0003]

2. Description of the Related Art The display surface of an image display device such as a liquid crystal display (LCD) or a cathode ray tube display device (CRT) is provided with a reflection of a light beam emitted from an external light source such as a fluorescent lamp in order to enhance its visibility. It is required to be small.

It has been known that the reflectance is reduced by coating the surface of a transparent object with a transparent film having a small refractive index, and an antireflection film utilizing such a phenomenon is displayed on an image display device. It can be provided on the surface to improve the visibility. The antireflection film has a single-layer structure in which a low refractive index layer having a small refractive index is provided on the display surface, or a medium to high refractive index layer is formed on the display surface in order to further improve the antireflection effect. It has a multilayer structure in which a plurality of layers are provided and a low refractive index layer for reducing the refractive index of the outermost surface is provided on the middle to high refractive index layer.

Further, in order to prevent the visibility from being deteriorated due to the adhesion of dust or the like to the display surface, an antistatic film having relatively weak conductivity may be provided on the display surface. The antistatic film is
The antireflection film may be provided on the display surface together with the antireflection film, or may be provided as a single layer of the antireflection film, or only the antistatic film may be provided on the display surface which does not require the antireflection film. Transparency is required to ensure

Further, when the above antireflection film or antistatic film is provided on a plastic whose surface is soft and easily scratched, a hard coat layer is formed as a base on the substrate,
It is desirable to provide an antireflection film or an antistatic film via the hard coat layer, but in this case, the hard coat layer is also required to have transparency.

Further, a transparent conductive film having a relatively high conductivity is incorporated as a transparent electrode in a liquid crystal display device or the like.

The method of forming each layer included in such an antireflection film or the conductive transparent thin film used as a transparent conductive film or the like is generally classified into a vapor phase method and a coating method. There are physical methods such as vacuum deposition method and sputtering method and chemical methods such as CVD method, and the coating method is a roll coating method, a gravure coating method, a slide coating method, a spray method, a dipping method, and a screen. There are printing methods.

In the case of the vapor phase method, it is possible to form a high-performance and high-quality transparent thin film, but it is necessary to precisely control the atmosphere in a high vacuum system, and a special heating device or ion is used. There is a problem in that the generation acceleration device is required, and the manufacturing device is complicated and large in size, which inevitably increases the manufacturing cost. Further, in the case of the vapor phase method, it is difficult to increase the area of the transparent thin film or to form the transparent thin film having a uniform film thickness on the surface of a film having a complicated shape.

On the other hand, in the case of the spray method among the coating methods, there are problems that the utilization efficiency of the coating liquid is poor and it is difficult to control the film forming conditions. When the roll coating method, the gravure coating method, the slide coating method, the dipping method, the screen printing method and the like are used, the film forming raw materials are efficiently used and are advantageous in terms of mass production and equipment cost. The transparent thin film obtained by the coating method is inferior in function and quality to those obtained by the vapor phase method.

In recent years, as a coating method capable of forming thin films of a high refractive index layer and a medium refractive index layer having excellent quality, high refractive index fine particles such as titanium oxide or tin oxide or A method has been proposed in which a coating liquid in which fine particles having a refractive index and conductivity are dispersed is applied onto a substrate to form a coating film.

Since it is essential that the coating film forming the medium to high refractive index layer is transparent in the visible light region, the high refractive index fine particles are so-called ultrafine particles having a primary particle diameter of not more than the wavelength of visible light. In addition to being used, it is necessary to uniformly disperse the high refractive index fine particles in the coating liquid and the coating film. However, in general, when the particle size of fine particles is reduced,
The surface area of the fine particles increases, and the cohesive force between the particles increases. When the solid components of the coating liquid are aggregated, the haze of the obtained coating film is deteriorated and the transparency is lowered, or the uniformity of the coating film is deteriorated and the film strength and the adhesion of the adjacent layer are lowered. Cause problems. Therefore, the coating liquid for forming the thin films of the high refractive index layer and the medium refractive index layer is required to have sufficient dispersibility to form a uniform coating film with a small haze. Further, the coating liquid is required to have sufficient dispersion stability so that it can be easily stored for a long period of time.

The problem of agglomeration of ultrafine particles can be solved by using a dispersant having good dispersibility for the ultrafine particles. The dispersant is adsorbed on the surface of the fine particles while penetrating between the fine particles to be agglomerated, and enables the uniform dispersion in the solvent while loosening the agglomerated state during the dispersion treatment. However, since the surface area of the ultrafine particles is increased, a large amount of dispersant is required to uniformly disperse the ultrafine particles in the coating liquid and to stabilize the ultrafine particles to withstand long-term storage. When a large amount of a dispersant is added to the coating liquid, a large amount of the dispersant also exists in the coating film formed by using the coating liquid, the dispersant hinders the curing of the binder component, and the coating film strength is Extremely lower.

Further, from the viewpoint of mass production, the coating liquid can be uniformly thinly applied at the time of coating so that a large-area thin film can be easily formed, and coating unevenness does not occur. Aptitude is required.

Further, the medium to high refractive index layer is required to have sufficient adhesion to the hard coat layer and the low refractive index layer adjacent to the medium to high refractive index layer. When a low refractive index layer such as a silicon oxide (SiOx) film is formed by a so-called dry method such as a vapor deposition method on a medium to high refractive index layer formed from a coating liquid by a so-called wet method,
Since the adhesiveness is extremely insufficient and peels off easily, particularly excellent adhesiveness is required.

The hard coat layer originally has a role as a support layer for the medium to high refractive index layer in order to prevent the antireflection film from being scratched. When the high refractive index hard coat layer also has a function as a high refractive index layer by blending, the high refractive index layer becomes unnecessary, and the number of constituent layers of the antireflection film can be reduced. However, the thickness of the medium-high refractive index layer is 0.05-0.
The thickness of the hard coat layer is about 2 μm, but 0.2 to 20 μm for the original purpose of ensuring sufficient hardness.
When the high-refractive-index hard coat layer is formed by the wet method using a coating solution similar to the medium-to-high-refractive-index layer coating solution, the medium- to high-refractive index is formed. Even when the layer is formed by the wet method, the transparency is likely to be deteriorated due to the aggregation of the high refractive index fine particles. Moreover,
While high hardness is required for the hard coat layer,
As described above, since the dispersant has a property of hindering the binder curing of the coating film, the amount of the dispersant that can be added to the coating liquid for the hard coat layer is higher than that of the coating liquid for the medium to high refractive index layer. Limited. Therefore, the demand for reducing the dispersant for the coating liquid for high refractive index hard coat layer is more severe than that for the coating liquid for medium to high refractive index layer.

[0017]

SUMMARY OF THE INVENTION The present invention has been accomplished in view of the above circumstances, and its first purpose is to provide a coating film with some function such as a predetermined refractive index and conductivity. Dispersibility in the coating composition,
It is to provide raw material fine particles having excellent dispersion stability.

A second object of the present invention is to obtain fine haze with a small haze, which is excellent in dispersibility and dispersion stability of fine particles to be added for imparting a predetermined function such as a predetermined refractive index and conductivity to the coating film. An object of the present invention is to provide a coating composition having good storage stability and capable of retaining film strength that can withstand actual use. A third object of the present invention is to provide a coating composition which has excellent dispersibility and dispersion stability as well as coating suitability and which can form a large-area thin film.

A fourth object of the present invention is to provide a transparent thin film having a certain function, particularly a low refractive index layer or a medium to high refractive index, by using the coating composition capable of achieving the above second or third object. Suitable for forming layers included in antireflection films such as layers and high-refractive-index hard coat layers, or forming conductive transparent thin films such as antistatic films, antistatic hard coat layers, and transparent electrode films To provide a transparent coating film.

A fifth object of the present invention is to be suitably used as an antireflection film, an antistatic film or a hard coat film which is preferably applied to a display surface of an image display device, and a pixel driving element of the image display device. It is to provide a transparent conductive film.

A fifth object of the present invention is to provide an antireflection film, an antistatic film, a hard coat film and a transparent conductive film using such an antireflection film, an antistatic film, a hard coat film and a transparent conductive film. To do.

The present invention solves at least one of these objects.

[0023]

Means for Solving the Problems A composite body according to the present invention for solving the above problems comprises a polymer portion having a polymer structure having a number average molecular weight of 2,000 to 20,000,
Inorganic oxide fine particles having a primary particle diameter in the range of 0.01 to 0.1 μm are covalently bonded.

Since the inorganic oxide fine particles having a primary particle size in the range of 0.01 to 0.1 μm have excellent transparency, a composite composed of the inorganic oxide fine particles and the polymer portion is formed. By dispersing in the coating film, without impairing the transparency of the coating film, to impart some function due to the physical properties of the inorganic oxide fine particles, for example, a refractive index adjusted to a predetermined value or conductivity. You can

Further, although the inorganic oxide fine particles originally have poor dispersibility in an organic solvent, the composite according to the present invention has a polymer covalently bonded to at least a part of the surface of the inorganic oxide fine particles. (In other words, the polymer is grafted on the surface of the particles), so that the polymer chains are interposed between the adjacent particles to prevent the particles from aggregating. Therefore, the composite according to the present invention can be uniformly dispersed in the coating liquid and stably over a long period of time by using a very small amount of the dispersant. When the composite of the present invention is used, in an ideal case, a coating liquid having excellent dispersibility and dispersion stability can be prepared without using any dispersant.

As the polymer portion of the composite, it is preferable to use an α, β-ethylenically unsaturated monomer polymer and / or a polysiloxane polymer.

It is preferable that at least a part of the surface of the inorganic oxide fine particles forming the above composite is coated with an inorganic compound that reduces or eliminates the photocatalytic activity. By suppressing the photocatalytic activity originally possessed by the inorganic oxide fine particles by coating with the inorganic compound, it becomes possible to prevent deterioration of the thin film when the composite is dispersed in the optical thin film.

The composite according to the present invention can be preferably used as a material for an optical thin film. In particular, when the titania fine particles (titanium oxide fine particles) whose surface is at least partially coated with an inorganic compound that reduces or eliminates the photocatalytic activity is used as the inorganic oxide fine particles forming the composite, the thin film is transparent. The refractive index can be adjusted without impairing the property, and in particular, the range of medium to high refractive index of the antireflection film can be covered. Further, in this case, since the photocatalytic activity of titanium oxide is used after being reduced or eliminated by performing a surface treatment with an inorganic compound, the yellow strength, which causes a reduction in the strength of the coating film due to the deterioration of the binder component and a reduction in antireflection performance, is caused. A strange phenomenon is hard to occur.

Next, the coating composition according to the present invention comprises at least (1) the composite resistance according to the present invention,
It is composed of (2) a binder component and (3) an organic solvent.

In the coating composition according to the present invention, the inorganic oxide fine particles have a number average molecular weight of 2,000 to 20,000.
Since a polymer having no affinity for the organic solvent or the binder component is blended by covalently bonding the polymer of 0, it is possible to sufficiently disperse the inorganic oxide fine particles.
Therefore, the coating composition according to the present invention can obtain high transparency required for an optical member such as an antireflection film, and can use no dispersant at all or only an extremely small amount. The strength of can be sufficiently secured.

Further, the coating composition of the present invention is excellent not only in the dispersibility immediately after preparation but also in the dispersion stability over a long period of time, so that the pot life is long.

The coating composition of the present invention is also excellent in coating suitability and can easily form a uniform large-area thin film.

Further, when the photocatalytic activity of the inorganic oxide fine particles is used after being reduced or eliminated by performing a surface treatment with an inorganic compound, the strength of the coating film is deteriorated due to the deterioration of the binder component and the antireflection performance is deteriorated. The yellowing phenomenon that causes

As the binder component, it is preferable to use a photocurable binder component which can be exposed and cured after coating. In particular, it is preferable to use a binder component having an anionic polar group among the photocurable binder components. Since the binder component having an anionic polar group has a high affinity with the inorganic oxide fine particles and acts as a dispersion aid, it improves the dispersibility of the inorganic oxide fine particles in the coating composition and the coating film. It also has the effect of reducing the amount of dispersant used. Since the dispersant does not function as a binder, the coating strength can be improved by reducing the blending ratio of the dispersant.

The binder component particularly preferably has a hydrogen bond-forming group as an anionic polar group. When the binder component has a hydrogen bond-forming group, in addition to improving the dispersibility of titanium oxide due to the effect as an anionic polar group, hydrogen bonding to an adjacent layer such as a hard coat layer or a low refractive index layer It is possible to improve the adhesion.

In particular, when forming a medium to high refractive index layer using a coating composition containing a binder component having a hydrogen bond-forming group, a dry film having high adhesion is formed on the medium to high refractive index layer. A coating film, for example, a silicon oxide (SiOx) vapor deposition film can be formed, which is very useful.

When the binder component having an anionic polar group described above is used, the inorganic oxide fine particles 1 can be used without using a dispersant at all or in an extremely small amount.
The binder component may be mixed in an amount of 4 to 20 parts by weight with respect to 0 parts by weight to prepare a coating composition having high dispersibility. The coating composition having such a mixing ratio is particularly suitable for forming a relatively thin coating film such as a low refractive index layer, a medium to high refractive index layer, an antistatic layer, a transparent electrode film.

When a binder component having an anionic polar group is used, the inorganic oxide fine particles 10 may be used without using a dispersant at all or in an extremely small amount.
To 40 parts by weight of the binder component.
It is possible to prepare a coating composition which is particularly suitable for forming a relatively thick coating film such as a high refractive index hard coat layer or a conductive hard coat layer by mixing in a proportion of parts by weight.

A ketone solvent is preferably used as the organic solvent. When the coating composition according to the present invention is prepared using a ketone-based solvent, it can be easily and uniformly applied to the surface of the substrate, and the evaporation rate of the solvent after application is moderate, and uneven drying is unlikely to occur. Therefore, a large-area coating film having a uniform thickness can be easily obtained.

The coating film according to the present invention can be obtained by applying the coating composition according to the present invention to the surface of the article to be coated and curing it if necessary. The coating film after curing is
A binder obtained by covalently bonding a polymer part having a polymer structure having a number average molecular weight of 2,000 to 20,000 and inorganic oxide fine particles having a primary particle diameter in the range of 0.01 to 0.1 μm is a binder. It is one that is uniformly mixed.

This coating film has high transparency and a small haze, and the function and performance can be adjusted by controlling the blending amount of the inorganic oxide fine particles, so that it can be utilized as various functional transparent thin films. Typically, an optical thin film such as a low refractive index layer of an antireflection film, a medium to high refractive index layer or a high refractive index hard coat layer, an antistatic film, an antistatic hard coat layer, a transparent electrode film, etc. It can be suitably used for forming a conductive transparent thin film.

Further, when the binder in this coating film has a hydrogen bond forming group, the adhesiveness to the adjacent layer, especially to the dry coating film such as the vapor deposition film becomes good.

According to the present invention, the film thickness after curing is from 0.05 to
When a 0.2 μm coating film is formed, the refractive index is 1.55
Adjust to the range of 2.30 and JIS-K7361-
It is possible to suppress the haze value measured in the state of being integrated with the base material in accordance with the provisions of 1 with the haze value of only the base material or to suppress the difference from the haze value of the base material within 10%. Yes, a medium to high refractive index layer can be formed.

Further, according to the present invention, the film thickness after curing is 0.
When forming a coating film of 2 to 20 μm, the refractive index is 1.55
To 2.30, and the haze value specified in JIS-K7361-1 does not differ from the haze value of the base material only, or the difference from the haze value of the base material is within 20%. It can be suppressed, and a high refractive index hard coat layer can also be formed.

[0045]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below. In the present specification, (meth) acryloyl represents acryloyl and methacryloyl, (meth) acrylate represents acrylate and methacrylate,
(Meth) acrylic represents acrylic and methacrylic.

First, the composite according to the present invention will be described. The composite according to the present invention has a number average molecular weight of 2,000.
To 20,000 polymer moieties having a polymer structure and inorganic oxide fine particles having a primary particle diameter in the range of 0.01 to 0.1 μm are covalently bonded, and the coating film has a predetermined refractive index. It can be preferably used as a material for imparting some function such as conductivity and conductivity.

The composite according to the present invention has the following features. (1) Since the inorganic oxide fine particles that are a constituent component of the composite have excellent transparency, it is possible to impair the transparency of the coating by dispersing the composite according to the present invention in the coating. However, it is possible to impart some function due to the physical properties of the inorganic oxide fine particles, for example, a refractive index adjusted to a predetermined value or conductivity. (2) Although the inorganic oxide fine particles originally have poor dispersibility in an organic solvent, the composite according to the present invention has a polymer covalently bonded to at least a part of the surface of the inorganic oxide fine particles (in other words, (For example, because the polymer is grafted on the surface of the particles), the polymer chains are interposed between the adjacent particles to prevent the particles from aggregating. Therefore, the composite according to the present invention can be uniformly dispersed in the coating liquid and stably over a long period of time by using a very small amount of the dispersant. When the composite of the present invention is used, in an ideal case, a coating liquid having excellent dispersibility and dispersion stability can be prepared without using any dispersant.

The composite according to the present invention will be described in more detail below. First, the inorganic oxide fine particles are appropriately selected in consideration of the function to be imparted to the coating film.

For example, when it is desired to form a medium-refractive-index layer, a high-refractive-index layer or a high-refractive-index hard coat layer of an antireflection film, inorganic oxide fine particles having a relatively high refractive index are mixed in the coating composition. Adjust to a predetermined refractive index. Examples of the inorganic oxide having a high refractive index include titania (titanium oxide), zirconia (zirconium oxide), zinc oxide, tin oxide, cerium oxide, antimony oxide, tin-doped indium oxide (ITO), and antimony-doped. Tin oxide (ATO), zinc-doped indium oxide (IZO), aluminum-doped zinc oxide (AZ
O) and tin oxide (FTO) doped with fluorine can be used.

Among the inorganic oxides having a high refractive index, titanium oxide has a particularly high refractive index and high transparency,
It is suitable as a component for adjusting the refractive index. Titanium oxide includes rutile type, anatase type and amorphous type. In the present invention, it is preferable to use rutile type titanium oxide having a higher refractive index than the anatase type and amorphous type.

When it is desired to form the low refractive index layer of the antireflection film, fine particles of inorganic oxide having a relatively low refractive index are mixed with the coating composition to adjust the refractive index to a predetermined value.
As the inorganic oxide having a low refractive index, for example, magnesium fluoride, calcium fluoride, silicon dioxide or the like can be used.

When it is desired to form an antistatic film, a hard coat layer having a function as an antistatic film, or a conductive transparent thin film that can be used as a transparent conductive film, an inorganic oxide having a relatively high conductivity is used. The fine particles are blended with the coating composition to adjust the predetermined conductivity. Examples of the inorganic oxide having high conductivity include tin oxide, tin-doped indium oxide (ITO), antimony-doped tin oxide (ATO), zinc-doped indium oxide (IZO), and aluminum. Zinc oxide (AZO) and fluorine-doped tin oxide (FT
O) or the like can be used.

Particularly, the conductive inorganic oxides exemplified above have a relatively high conductivity and a relatively high refractive index.
When these are used, it is possible to impart conductivity with a high refractive index to the transparent thin film, and a medium to high refractive index layer having a function as an antistatic film, and a high refractive index having a function as an antistatic film. It is also possible to form a hard coat layer.

The inorganic oxide fine particles may be used in combination of two or more kinds. In that case, by combining inorganic oxide fine particles having different main functions, a transparent thin film having a plurality of functions in a well-balanced manner can be formed. For example, by combining rutile-type titanium oxide fine particles having a very large refractive index but small conductivity with the above conductive inorganic oxide having a very large conductivity but a smaller refractive index than rutile titanium oxide, a predetermined refractive index can be obtained. It is possible to form a high refractive index layer having excellent antistatic properties.

As the inorganic oxide, a so-called ultrafine particle size is used so as not to reduce the transparency of the coating film. Here, the “ultrafine particles” are generally particles on the order of submicrons, and have a particle size smaller than that of particles generally called “fine particles” having a particle size of several μm to several hundred μm. It means a small one. That is, in the present invention, the inorganic oxide fine particles have a primary particle diameter of 0.01 μm or more and 0.1 μm or less, preferably 0.03.
Use those with a size of less than μm. If the average particle size is less than 0.01 μm, it is difficult to uniformly disperse it in the coating composition, and it becomes impossible to obtain a coating film in which ultrafine inorganic oxide particles are uniformly dispersed. If the average particle diameter exceeds 0.1 μm, the transparency of the coating film is impaired, which is not preferable. The primary particle diameter of the inorganic oxide fine particles may be visually measured from an image photograph of secondary electron emission obtained by a scanning electron microscope (SEM) or the like, or a dynamic light scattering method or a static light scattering method may be used. It may be mechanically measured by a particle size distribution meter or the like used.

As long as the primary particle size of the inorganic oxide fine particles is within the above range, the particle shape may be spherical or needle-like, and any other shape can be used in the present invention. it can.

Photocatalytic activity is emphasized when the metal oxide fine particles have a small particle size and an increased surface area. Therefore, even zirconia fine particles which do not exhibit photocatalytic activity at a particle size of several μm are coated with an ultrafine particle size. When dispersed in a large amount in the film, if left in an environment containing ultraviolet rays such as sunlight, deterioration of the polymer used as a binder is caused, and along with that, the desired transparency, refractive index or conductivity is greatly changed. However, the performance of the thin film may be greatly impaired by leaving it for several days.

Therefore, it is preferable that at least a part of the surface of the inorganic oxide fine particles used in the present invention is coated with an inorganic compound that reduces or eliminates the photocatalytic activity. As the inorganic compound, one having a low photocatalytic activity in comparison with the inorganic oxide fine particles to be coated is selected and used.
The inorganic oxide fine particles are shielded from light rays by the inorganic compound having a photocatalytic activity weaker than its own photocatalytic activity, and the photocatalytic activity is suppressed.

Examples of the inorganic compound coating at least a part of the surface of the inorganic oxide fine particles include metal oxides such as alumina, silica, zinc oxide and zirconium oxide,
Antimony-doped tin oxide (ATO), tin-doped indium oxide (ITO), zinc-doped indium oxide (IZO), aluminum-doped zinc oxide (AZO), fluorine-doped tin oxide (F
Examples thereof include conductive complex metal oxides such as TO), and among these, one kind can be used alone or two or more kinds can be used in combination.

When the inorganic oxide fine particles are used to adjust the refractive index of the coating film to a high or low value, it is preferable to use an inorganic compound having a refractive index as high or low as possible in accordance with the inorganic oxide fine particles. .

It is possible to impart conductivity to the inorganic oxide fine particles by coating the inorganic oxide fine particles having no conductivity with the above-mentioned conductive composite metal oxide. For example, when titanium oxide fine particles having a high refractive index but no conductivity are used as the inorganic oxide fine particles for forming the high refractive index layer of the antireflection film, the surface of the titanium oxide fine particles is as described above. A high refractive index layer having an antistatic function can be obtained by applying conductivity by coating with such a conductive complex metal oxide.

In order to coat the surface of the inorganic oxide fine particles with an inorganic compound, a salt of the inorganic compound to be coated or an inorganic compound to be coated by hydrolysis is added to a dispersion liquid in which the inorganic oxide fine particles are dispersed in water. A desired inorganic compound is physicochemically adsorbed on the surface of the inorganic oxide fine particles by adding an organometallic compound capable of forming a compound and changing the pH and / or temperature conditions.

Inorganic oxide fine particles coated with an inorganic compound are also present in commercial products. For example, as titanium oxide coated with alumina, TTO51 (A) manufactured by Ishihara Sangyo Co., Ltd.
Alternatively, the MT-500 series of Teika Co., Ltd. can be obtained.

The surface of the inorganic oxide fine particles is coated with an inorganic compound in order to reduce or eliminate the photocatalytic activity, and a polymer is covalently bonded to enhance the dispersibility in an organic solvent to impart hydrophobicity.

The polymer portion covalently bonded to the surface of the inorganic oxide fine particles has a high affinity and compatibility with the organic solvent and / or the binder used when dispersing the inorganic oxide fine particles in the coating liquid. It is preferable to use, and it is possible to further improve the dispersibility and dispersion stability of the inorganic oxide fine particles by selecting a polymer having high affinity and compatibility with an organic solvent or a binder component. Is. For example, when an acrylate resin is used as the binder component of the coating liquid, it is preferable to covalently bond the α, β-ethylenically unsaturated monomer-based or polysiloxane-based polymer to the surface of the titanium oxide ultrafine particles.

Here, the α, β-ethylenically unsaturated monomer polymer to be covalently bonded to the surface of the inorganic oxide fine particles is obtained by homopolymerization or copolymerization using a monomer having an α, β-ethylenically unsaturated bond. Polymer.

As the monomer having an α, β-ethylenically unsaturated bond, those having one or more α, β-ethylenically unsaturated bonds as exemplified below can be used. From the viewpoint of solubility in a solvent, affinity with a binder component, and the like, a suitable combination of monomers is used among the monomers.

(1) Having one α, β-ethylenically unsaturated bond in the molecule: 1) Carboxyl group-containing monomer, for example, acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, Fumaric acid, etc .; 2) Hydroxyl group-containing monomer, for example, 2-hydroxyethyl acrylate, hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, allyl alcohol, methallyl alcohol, etc .; 3) Nitrogen-containing alkyl acrylate or methacrylate, for example, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, etc .; 4) Polymerizable amide, for example, acrylic acid amide, methacrylic acid amide, etc .; 5) Polymerizable nito. 6) Alkyl acrylate or methacrylate such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate, n-butyl methacrylate, 2-ethylhexyl acrylate, etc .; 7) Polymerization Aromatic compounds such as styrene, α-methylstyrene, vinyltoluene, t-butylstyrene and the like; 8) α-olefins such as ethylene and propylene; 9) Vinyl compounds such as vinyl acetate and vinyl propionate; ) Those having two or more α, β-ethylenically unsaturated bonds in the molecule: 10) Diene compounds such as butadiene and isoprene; 11) Polymerizable unsaturated monocarboxylic acid ester of polyhydric alcohol, polybasic acid Of the polymerizable Sulfo alcohol ester or aromatic compound substituted with two or more vinyl groups, for example, ethylene glycol diacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, Trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, 1,4-butanediol diacrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate. , Pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pen Pentaerythritol tetramethacrylate, glycerol dimethacrylate, glycerol diacrylate, glycerol Ali Loki Siji methacrylate, 1,1,1-tris hydroxymethyl ethane diacrylate, 1,1,
1-trishydroxymethylethane triacrylate,
1,1,1-Trishydroxymethylethane dimethacrylate, 1,1,1-Trishydroxymethylethane trimethacrylate, 1,1,1-Trishydroxymethylpropane diacrylate, 1,1,1-Trishydroxymethylpropane trimethacrylate Acrylate, 1,1,1-trishydroxymethylpropane dimethacrylate, 1,
1,1-trishydroxymethylpropane trimethacrylate, triallyl cyanurate, triallyl isocyanurate, triallyl trimellitate, diallyl terephthalate, diallyl phthalate, divinylbenzene and the like;
And combinations of these.

The polysiloxane-based polymer to be covalently bonded to the surface of the inorganic oxide fine particles has a dimethylpolysiloxane structure as a basic skeleton, and if necessary, at least a part thereof is a hydroxyl group, a carboxyl group, an epoxy group, or a glycidyl group. , A polymer containing an amide group and the like. Specifically, it is obtained by hydrolysis of the organosilicon compound represented by the following general formula (1).

Formula (1): RR'aSiX _3-a (wherein R is an organic group having 1 to 10 carbon atoms, R'is 1 carbon atom)
6 to a hydrocarbon group or a halogenated hydrocarbon group, X is a hydrolyzable group, and a is 0 or 1. ) Specific examples of the organosilicon compound include the following compounds. That is, methyltrimethoxysilane, methyltriethoxysilane, methyltrimethoxyethoxysilane, methyltriacetoxysilane, methyltripropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, vinyltrimethoxysilane. Ethoxysilane, vinyltriacetoxysilane, vinyltrimethoxyethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltriacetoxysilane, γ-chloropropyltrimethoxysilane, γ-chloropropyltriethoxysilane, γ-chloropropyltri Acetoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltrimetho Xysilane, γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltrimethoxyethoxysilane, γ-mercaptopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxy Silane, β-cyanoethyltriethoxysilane, methyltriphenoxysilane, chloromethyltrimethoxysilane, chloromethyltriethoxysilane, glycidoxymethyltrimethoxysilane, glycidoxymethyltriethoxysilane, α-glycidoxyethyltrimethoxy Silane, α-glycidoxyethyltriethoxysilane, β-glycidoxyethyltrimethoxysilane, β-glycidoxyethyltriethoxysilane, α-glycidoxypropyltrimethoxysilane, α
-Glycidoxypropyltriethoxysilane, β-glycidoxypropyltrimethoxysilane, β-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ -Glycidoxypropyltripropoxysilane, γ-glycidoxypropyltributoxysilane, γ-glycidoxypropyltrimethoxyethoxysilane, γ-glycidoxypropyltriphenoxysilane, α-glycidoxybutyltrimethoxysilane, α
-Glycidoxybutyltriethoxysilane, β-glycidoxybutyltrimethoxysilane, β-glycidoxybutyltriethoxysilane, γ-glycidoxybutyltrimethoxysilane, γ-glycidoxybutyltriethoxysilane, δ -Glycidoxybutyltrimethoxysilane,
δ-glycidoxybutyltriethoxysilane, (3,4
-Epoxycyclohexyl) methyltrimethoxysilane, (3,4-epoxycyclohexyl) methyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxy Silane, β-
(3,4-Epoxycyclohexyl) ethyltripropoxysilane, β- (3,4-epoxycyclohexyl)
Ethyltributoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxyethoxysilane, β
-(3,4-epoxycyclohexyl) ethyltriphenoxysilane, γ- (3,4-epoxycyclohexyl) propyltrimethoxysilane, γ- (3,4-epoxycyclohexyl) propyltriethoxysilane, δ
-(3,4-epoxycyclohexyl) butyltrimethoxysilane, δ- (3,4-epoxycyclohexyl)
Trialkoxysilane such as butyltriethoxysilane,
Triacyloxysilane or triphenoxysilanes,
Or a hydrolyzate thereof.

Further, the following compounds may be mentioned as specific examples of the organosilicon compound. That is, dimethyldimethoxysilane, phenylmethyldimethoxysilane, dimethyldiethoxysilane, phenylmethyldiethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropylmethyldiethoxysilane, dimethyldiacetoxysilane, γ-methacryloxypropylmethyl. Dimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, methylvinyldimethoxy Silane, methylvinyldiethoxysilane, glycidoxymethylmethyldimethoxysilane, glycidoxymethylmethyldiethoxysilane, α-glycy Carboxyethyl methyl dimethoxy silane, alpha-glycidoxy ethyl methyl diethoxy silane,
β-glycidoxyethylmethyldimethoxysilane, β-
Glycidoxyethylmethyldiethoxysilane, α-glycidoxypropylmethyldimethoxysilane, α-glycidoxypropylmethyldiethoxysilane, β-glycidoxypropylmethyldimethoxysilane, β-glycidoxypropylmethyldiethoxysilane , Γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropylmethyldipropoxysilane, γ-glycidoxypropylmethyldibutoxysilane, γ-glycidoxypropyl Methyldimethoxyethoxysilane, γ-glycidoxypropylmethyldiphenoxysilane, γ-glycidoxypropylmethyldiacetoxysilane, γ-glycidoxypropylethyldimethoxysilane, γ-glycidoxypropylethyldiethoxysilane Dialkoxysilanes such as γ-glycidoxypropylvinyldimethoxysilane, γ-glycidoxypropylvinyldiethoxysilane, γ-glycidoxypropylphenyldimethoxysilane and γ-glycidoxypropylphenyldiethoxysilane Phenoxysilane or diacyloxysilanes, or a hydrolyzate thereof.

As specific examples of the organosilicon compound represented by the above formula 1, dihalogenated silane such as dimethyldichlorosilane or a hydrolyzate thereof can be further exemplified.

In order to sufficiently separate the adjacent inorganic oxide fine particles to improve the dispersibility, the size and amount of the polymer portion are also important. If the size of the polymer portion to be bonded to the surface of the inorganic oxide fine particles is too small, it is impossible to prevent a sufficient distance between the inorganic oxide fine particles to prevent aggregation, while if the size of the polymer is too large, the polymer chain itself The cohesive force of the is so large that coagulation cannot be prevented.
From this point of view, the size of the polymer part has a number average molecular weight of 2,000 to 20,000.

If the amount of the polymer portion bonded to the surface of the inorganic oxide fine particles is too small, the inorganic oxide fine particles are likely to come into contact with each other and aggregation cannot be prevented. On the other hand, if the amount of the polymer portion is too large. However, the refractive index of the inorganic oxide fine particles decreases, and the desired refractive index cannot be obtained. From this perspective,
The amount of polymer part is 1 of the inorganic oxide fine particles themselves.
It is preferable to adjust the polymer part to about 1 part by weight with respect to 0 part by weight.

The method for bonding the polymer portion to the surface of the inorganic oxide fine particles is roughly classified into the following three methods.

(1) Method of supplementing the polymer growth end with inorganic oxide fine particles Since the hydroxyl group (-OH) present on the surface of the inorganic oxide fine particles has a function of capturing active species such as radicals, for example, inorganic oxidation is carried out. The polymer can be bonded to the surface of the fine particles by carrying out the polymerization reaction in the presence of the fine particles or by adding the inorganic oxide fine particles to the polymerization system. This is effective when kneading fine particles into a monomer to perform a polymerization reaction, such as bulk polymerization, but the binding efficiency is poor.

(2) Method of Initiating Polymerization Reaction from Surface of Inorganic Oxide Fine Particles By a method of forming a polymerization initiation active species such as a radical polymerization initiator on the surface of inorganic oxide fine particles in advance and growing a polymer from the surface of the fine particles. is there. It is easy to obtain a high molecular weight polymer, but it is difficult to control chain transfer and the like.

(3) Method of Bonding Polymer Having Reactive Group to Hydroxyl Group on Surface of Inorganic Oxide Fine Particles Using a polymer having a reactive group at the terminal, the reactive group at the end of the polymer and the surface of inorganic oxide fine particle are This is a method of directly bonding with a hydroxyl group, or by bonding another reactive group to either or both of the reactive group at the polymer terminal and the hydroxyl group on the surface of the inorganic oxide fine particles. Many kinds of polymers can be used, and the coupling efficiency is good with a relatively simple operation.

The polymer having a reactive group can be obtained by incorporating a monomer having a reactive group among the above-exemplified monomers. Commercially available products include, for example, Toagosei Co., Ltd.'s macromonomer series and Soken Chemical Co., Ltd. It can be appropriately selected and used from the company Actflow series (all copolymers of α, β-ethylenically unsaturated monomers) and reactive silicones from Shin-Etsu Chemical Co., Ltd. and GE Toshiba Silicone Co., Ltd.

Since the method of binding the polymer to the surface of the inorganic oxide fine particles utilizes a dehydration polycondensation reaction between the surface hydroxyl group and the polymer having a reactive group, the inorganic oxide fine particles are dispersed in the polymer and the solution thereof. And heat at 80 ° C or higher for 3 hours or longer.

The inorganic oxide fine particles may be first coated with an inorganic compound and then bonded with a polymer portion, or may be previously bonded with a polymer portion and then coated with an inorganic compound. .

Next, the coating composition according to the present invention will be described. The coating composition according to the present invention,
A coating material comprising at least (1) the composite according to the present invention, (2) a binder component, (3) a dispersant having an anionic polar group, and (4) an organic solvent,
If necessary, it may contain other components.

Among the above-mentioned essential components, the complex is the main component for imparting some function to the coating film formed by using the coating composition according to the present invention as described above.

The binder component is added as an essential component to the coating composition according to the present invention in order to impart film-forming properties and adhesion to the substrate and adjacent layers.

As the binder component which is not reaction-curable by itself, a non-polymerization reactive transparent resin which has been conventionally used for forming an optical thin film, such as polyacrylic acid, polymethacrylic acid or polyacrylate, Examples thereof include polymethacrylate, polyolefin, polystyrene, polyamide, polyimide, polyvinyl chloride, polyvinyl alcohol, polyvinyl butyral, and polycarbonate.

However, in order to impart sufficient strength, durability and adhesiveness to the coating film, the coating composition according to the present invention was applied to the surface of the article to be coated and dried if necessary. After that, it is preferable to use a binder component which is polymerized, preferably crosslinked and cured by some chemical reaction. As such a reaction-curable binder component,
For example, a compound that can be photocured by a photoradical polymerization reaction or thermally cured by a thermal radical polymerization reaction, such as an ethylenically unsaturated bond-containing compound represented by a (meth) acrylate-based monomer, oligomer, or polymer, or an epoxy. A compound that can be photocured by thermosetting or photocationic polymerization such as resin can be used.

Among the reaction-curable binder components, a crosslinkable monomer or oligomer having two or more reaction-curable groups in one molecule and having a small molecular weight is excellent in coating suitability of the coating composition and is uniform. It is easy to form a large area thin film.

By adding a photocurable binder component to the coating composition according to the present invention, sufficient strength, durability and adhesiveness can be imparted to the coating film, and curing having a fine structure by pattern exposure. It is preferable because the film can be easily formed. In the following,
In particular, the photocurable binder component will be described in detail.

As the photocurable binder component, a polymerization reaction is carried out directly by irradiation with visible light, ionizing radiation such as ultraviolet rays or electron beams, or other invisible light, or indirectly by the action of an initiator. Monomers or oligomers with resulting functional groups can be used. In the present invention, a radical-polymerizable monomer or oligomer having an ethylenically unsaturated bond can be mainly used, and a photoinitiator is combined as necessary. However, it is also possible to use other photocurable binder components, for example, a photocationically polymerizable monomer or oligomer such as an epoxy group-containing compound may be used. If necessary, a photocationic initiator is used in combination with the photocationic polymerizable binder component. The monomer or oligomer that is the binder component is preferably a polyfunctional binder component having two or more polymerizable functional groups so that cross-linking occurs between the molecules of the binder component.

Specific examples of the radical-polymerizable monomer and oligomer having an ethylenically unsaturated bond include:
Monofunctional (meth) compounds such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, hydroxybutyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, carboxypolycaprolactone acrylate, acrylic acid, methacrylic acid and acrylamide. Acrylate: Diacrylate such as pentaerythritol triacrylate, ethylene glycol diacrylate, pentaerythritol diacrylate monostearate; Tri (meth) acrylate such as trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate derivative or dipenta Polyfunctional (meth) acrylates such as erythritol pentaacrylate, or their radicals Le polymerizable monomer can be exemplified oligomers polymerized.

Among the photocurable binder components, the binder component having an anionic polar group has a high affinity for the inorganic oxide fine particles and acts as a dispersion aid.
Therefore, it is preferable since it has the effect of improving the dispersibility of the inorganic oxide fine particles in the coating composition and the coating film in cooperation with the polymer on the surface of the inorganic oxide fine particles and reducing the amount of the dispersant used.

The binder component particularly preferably has a hydrogen bond-forming group as an anionic polar group. When the binder component has a hydrogen bond-forming group, in addition to improving the dispersibility of the inorganic oxide fine particles by the effect as an anionic polar group, a hydrogen bond causes a hard coat layer, a low refractive index layer, and a transparent electrode. It is possible to improve the adhesion to adjacent layers such as layers.

For example, when a medium to high refractive index layer is formed using a coating composition containing a binder component having a hydrogen bond forming group, a hard coat layer formed from a coating solution by a so-called wet coating method, Excellent adhesion can be obtained to the low refractive index layer and other light transmitting layers, and also to the low refractive index layer formed by so-called dry coating method such as vapor deposition method and other light transmitting layers.

As the low refractive index layer, a silicon oxide (SiOx) film may be formed by a vapor deposition method which is a dry method or a sol-gel reaction which is a wet method. Although the silicon oxide film contains a silanol group and can form a hydrogen bond,
For such a film containing a hydrogen bond-forming group, a binder component having a hydrogen bond-forming group has a great effect on dramatically improving the adhesiveness.

Conventionally, a medium-sized film formed by the wet method is used.
When forming a silicon oxide film on the high refractive index layer by vapor deposition, sufficient adhesion was not obtained, and the silicon oxide vapor deposition film was easy to peel off, while a binder component having a hydrogen bond forming group was used. Medium with the blended coating composition
When forming a high refractive index layer, a silicon oxide (SiOx) vapor-deposited film can be formed on the medium to high refractive index layer with good adhesion, which is very useful.

Further, for the purpose of antistatic, I was added to the antireflection film.
In some cases, a transparent conductive layer such as a TO vapor deposition film or an ATO vapor deposition film is provided, and a hard coat layer is formed on the transparent conductive layer. Even in such a case, by using a coating composition containing a binder component having a hydrogen bond-forming group, a high refractive index hard coat layer can be formed with good adhesion, which is very useful.

As the photocurable binder component having a hydrogen bond forming group, specifically, a binder component having a hydroxyl group in the molecule can be used. As the binder component having a hydroxyl group in the molecule, a pentaerythritol polyfunctional (meth) acrylate or a dipentaerythritol polyfunctional (meth) acrylate, which has a hydroxyl group in the molecule, can be used. That is, in such a binder component, two or more molecules of (meth) acrylic acid are ester-bonded to one molecule of pentaerythritol or dipentaerythritol. Some of them remain unesterified, and for example, pentaerythritol triacrylate can be exemplified. Since pentaerythritol polyfunctional acrylate and dipentaerythritol polyfunctional acrylate have two or more ethylenic double bonds in one molecule, a cross-linking reaction occurs during polymerization, and high coating strength can be obtained.

Examples of the photoinitiator for initiating radical polymerization include acetophenones, benzophenones, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds, disulfide compounds. , Thiuram compounds, fluoroamine compounds and the like are used. More specifically, 1
-Hydroxy-cyclohexyl-phenyl-ketone, 2
-Methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one, benzyl dimethyl ketone, 1- (4-dodecylphenyl) -2-hydroxy-
2-methylpropan-1-one, 2-hydroxy-2-
Methyl-1-phenylpropan-1-one, 1- (4-
Examples include isopropylphenyl) -2-hydroxy-2-methylpropan-1-one and benzophenone.
Among these, 1-hydroxy-cyclohexyl-
Phenyl-ketone and 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropane-1-
ON is preferably used in the present invention because even a small amount of ON initiates and accelerates the polymerization reaction upon irradiation with ionizing radiation. These can be used alone or in combination of both. They also exist in commercial products, for example 1-hydroxy-cyclohexyl-phenyl-ketone is available from Irgacure 184.
It can be obtained from Japan Ciba Geigy under the product name of 4).

The coating composition according to the present invention contains inorganic oxide fine particles, a binder component, and an organic solvent as essential components, but may further contain other components, if necessary. For example, when an ionizing radiation-curable binder component is used, it may contain a polymerization initiator. In addition, if necessary, an ultraviolet screening agent,
UV absorber, surface conditioner (leveling agent), zirconium oxide, tin oxide doped with antimony (ATO)
Etc. can be used.

When a high refractive index hard coat layer is formed by using the above coating composition, the coating composition is blended with organic fine particles to apply the composition.
The surface of the high-refractive-index hard coat layer can be made finely uneven to provide a function as an anti-glare layer. Here, as the organic fine particles for forming fine irregularities, specifically, the average particle diameter by SEM observation is 0.5 to 10.
Styrene beads and acrylic beads of about 0 μm, and
Styrene / acrylic copolymer beads can be used.

The organic solvent for dissolving and dispersing the solid component of the coating composition of the present invention is not particularly limited, and various ones such as isopropyl alcohol, methanol,
Alcohols such as ethanol; ketones such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; esters such as ethyl acetate and butyl acetate; halogenated hydrocarbons; aromatic hydrocarbons such as toluene and xylene.
Alternatively, a mixture of these can be used.

In the present invention, it is preferable to use a ketone type organic solvent. When the coating composition according to the present invention is prepared using a ketone-based solvent, it can be easily and uniformly applied to the surface of the substrate, and the evaporation rate of the solvent after application is moderate, and uneven drying is unlikely to occur. Therefore, a large-area coating film having a uniform thickness can be easily obtained.

In order to impart a function as an antiglare layer to the hard coat layer which is a support layer of the antireflection film, the surface of the hard coat layer is formed into fine irregularities, and the coating composition according to the present invention is applied thereon. Then, a medium refractive index layer or a high refractive index layer may be formed. When the coating composition according to the present invention is prepared using a ketone solvent, it can be applied even to the surface of such fine irregularities,
Uneven coating can be prevented.

As the ketone solvent, a single solvent composed of one kind of ketone, a mixed solvent composed of two or more kinds of ketone, and a solvent containing one or more kinds of ketone and another solvent, and the property as a ketone solvent You can use the one that has not lost. It is preferable to use a ketone solvent in which 70% by weight or more, particularly 80% by weight or more, of the solvent is occupied by one or more ketones.

By using a ketone solvent as the organic solvent and covalently bonding the above-described polymer to the surface of the inorganic oxide fine particles, a coating composition having particularly excellent coating suitability can be obtained, and a uniform large-area thin film can be obtained. Can be easily formed. Even in this case, α, β having a number average molecular weight of 2,000 to 20,000 on the surface of the inorganic oxide fine particles.
-It is more preferable to covalently bond an ethylenically unsaturated monomer-based polymer and / or a polysiloxane-based polymer. Alternatively, as the binder component, it is also effective to use a pentaerythritol polyfunctional (meth) acrylate or dipentaerythritol polyfunctional (meth) acrylate binder component having a hydroxyl group in the molecule.

In the present invention, the dispersibility is improved by covalently bonding a polymer to the surface of the inorganic oxide fine particles, and more preferably, a binder component having an anionic polar group in the molecule is used for dispersion. Since it acts as an auxiliary agent, the amount of the dispersant used can be greatly reduced. Since the dispersant does not function as a binder, the coating strength can be improved by reducing the blending ratio of the dispersant.

The blending ratio of each component can be appropriately adjusted. In particular, when a binder component having an anionic polar group is used, even if the dispersant is not used at all or only an extremely small amount is used, the inorganic The binder component having the anionic polar group can be mixed in an amount of 4 to 20 parts by weight with respect to 10 parts by weight of the oxide fine particles to prepare a coating composition having high dispersibility. This blending ratio is suitable as a coating composition for forming a relatively thin coating film such as a low refractive index layer, a medium to high refractive index layer, an antistatic layer and a transparent electrode film.

When a binder component having an anionic polar group is used, the inorganic oxide fine particles 10 may be used without using a dispersant at all or in an extremely small amount.
It is possible to mix the binder component having an anionic polar group in the molecule in an amount of 4 to 40 parts by weight with respect to 20 parts by weight to uniformly and stably dissolve and disperse in an organic solvent. .

It is necessary that the compounding ratio is such that, as in the high refractive index hard coat layer or the conductive hard coat layer, some function is added by the inorganic oxide fine particles and the layer is thicker than the medium to high refractive index layer. It is suitable as a coating composition for forming a certain hard coat layer. When preparing a coating composition for forming the high refractive index hard coat layer, 1 to 20 parts by weight of organic fine particles for imparting a function as an antiglare layer may be added.

When a photopolymerization initiator is used, it is usually used in an amount of 3 parts by weight per 100 parts by weight of the binder component.
-8 parts by weight.

The amount of the organic solvent is appropriately selected so that the respective components can be uniformly dissolved and dispersed, no aggregation occurs during storage after preparation, and a concentration that is not too dilute during coating. Adjust. Within the range where this condition is satisfied, the amount of solvent used is reduced to prepare a high-concentration coating composition,
It is preferable to store the product in a state where it does not take up a volume, take out a necessary amount at the time of use, and dilute it to a concentration suitable for coating work. In the present invention, when the total amount of the solid content and the organic solvent is 100 parts by weight, 50 to 9 parts by weight of the organic solvent is added to 0.5 to 50 parts by weight of the total solid content including the essential components and other components.
5.5 parts by weight, more preferably 10 to 30 total solids
By using the organic solvent in an amount of 70 to 90 parts by weight with respect to parts by weight, a coating composition having excellent dispersion stability and suitable for long-term storage can be obtained.

In order to prepare the coating composition according to the present invention using each of the above components, the dispersion treatment may be carried out according to a general method for preparing a coating liquid. For example, a coating composition can be obtained by mixing each essential component and each desired component in an arbitrary order, adding a medium such as beads to the obtained mixture, and appropriately dispersing the mixture with a paint shaker or a bead mill. .

The coating composition thus obtained is
As an essential component, a number average molecular weight of 2,000 to 20,000
A composite in which a polymer part of 0 and an inorganic oxide fine particle having a predetermined primary particle size are covalently bonded, and a binder component are dissolved and dispersed in an organic solvent.

The coating composition according to the present invention comprises a polymer which is covalently bonded to the surface of the inorganic oxide fine particles, and more preferably, the inorganic oxide is prepared by the cooperative action of the polymer and a binder component having an anionic polar group. It has excellent dispersibility and dispersion stability of fine particles,
The haze is very small. That is, the amount of the inorganic oxide fine particles contained in the form of a composite in the coating composition according to the present invention is controlled, and the coating composition is applied to the surface of a substrate to be coated such as a substrate and dried. By curing as necessary, some function due to the physical properties of the inorganic oxide fine particles is added, and a coating film having high transparency, small haze, and film strength that can withstand actual use can be obtained. .

Further, the coating composition of the present invention can disperse the inorganic oxide fine particles uniformly even if the dispersing agent is not contained at all or only in a small amount. It is possible to increase the mixing ratio of the fine particles to impart a high function to the coating film, or to increase the mixing ratio of the binder component to increase the strength of the coating film.

Therefore, the coating composition according to the present invention is suitable for forming an optical thin film which is required to have high transparency, and for example, it forms one or more layers constituting an antireflection film. Can be used for. In particular, when the inorganic oxide fine particles having a high refractive index are blended in the coating composition according to the present invention, a medium refractive index layer, a high refractive index layer or a high refractive index hard coat layer of the antireflection film is formed. Suitable for Further, when the coating composition according to the present invention is blended with highly conductive inorganic oxide fine particles, a highly transparent conductive transparent thin film is obtained, and an antistatic film provided on an optical thin film such as an antireflection film. It is also suitable for forming a transparent electrode film or the like provided in a pixel driving element of a liquid crystal display device.

Since the coating composition according to the present invention can reduce the amount of the dispersant used as much as possible, it is not only superior in terms of refractive index and coating film strength, but also various dispersants affect the coating film. It is possible to reduce adverse effects.
For example, if it is considered to increase the production speed to reduce the product cost and increase the production quantity per unit time, the UV irradiation amount for curing is half or three of the current level.
Although it is reduced to about one-tenth, such a small irradiation amount tends to cause insufficient curing of the binder component of the coating film.
In the case where such a coating film that is insufficiently cured contains a large amount of a dispersant, when the coating film is placed under high humidity of about 80 ° C. and 90% RH, the dispersant is the surface of the coating film. And the adhesiveness to an adjacent layer such as a low refractive index layer laminated on the coating film is extremely reduced. On the other hand, when the coating composition according to the present invention is used, the amount of the dispersant used can be reduced as much as possible, and thus it is possible to prevent the adverse effect of the dispersant.

Further, the coating composition according to the present invention is excellent in dispersion stability over a long period of time, so that it has a long pot life and is highly transparent even when used after being stored for a long period of time and has a small haze. A film can be formed.

Furthermore, the coating composition according to the present invention is excellent in coating suitability and can be easily and thinly and widely and uniformly applied to the surface of the article to be coated, and a uniform large-area thin film can be formed. In particular, when a ketone-based solvent is used, the evaporation rate is appropriate and the unevenness of the coating film is unlikely to occur, so that a uniform large-area thin film is particularly easy to form.

The antireflective coating composition of the present invention is applied to the surface of an article to be coated such as a substrate, dried, and optionally cured by a chemical reaction step such as irradiation with ionizing radiation to obtain a substance. A colorless and transparent coating film having a small haze can be formed.

The support to which the coating composition of the present invention is applied is not particularly limited. Preferred base materials include, for example, glass plates; triacetate cellulose (TA
C), polyethylene terephthalate (PET), diacetyl cellulose, acetate butyrate cellulose, polyether sulfone, acrylic resin; polyurethane resin; polyester; polycarbonate; polysulfone; polyether; trimethylpentene; polyether ketone; (meth) acrylonitrile Examples thereof include films formed of various resins such as The thickness of the substrate is usually about 25 μm to 1000 μm, preferably 50 μm to 190 μm.

The coating composition is, for example, spin coating method, dipping method, spraying method, slide coating method,
It can be coated on the substrate by various methods such as a bar coat method, a roll coater method, a meniscus coater method, a flexographic printing method, a screen printing method and a bead coater method.

The coating composition according to the present invention is applied on the surface of an article to be coated such as a base material in a desired coating amount, and then it is usually dried by heating with a heating means such as an oven, and then if necessary. Then, the coating film is formed by curing by an appropriate method such as irradiation with ionizing radiation such as ultraviolet rays or electron beams.

The coating film thus obtained is composed of a polymer part having a polymer structure having a number average molecular weight of 2,000 to 20,000 and an inorganic oxide having a primary particle size in the range of 0.01 to 0.1 μm. The composite formed by covalently bonding the product fine particles is uniformly mixed in the binder, but may contain other components as necessary. When the binder of the coating film is not just dried and solidified but cured by a crosslinking reaction, the film strength,
It is preferable because it has excellent physical properties such as hardness and durability.

The coating film obtained by the present invention can be suitably used as one or more layers constituting an antireflection film, and in particular, inorganic oxide fine particles having a high refractive index such as titanium oxide are blended. When the refractive index is adjusted by adjusting the refractive index, it is suitable for forming a medium to high refractive index layer. According to the present invention, when a coating film having a film thickness of 0.05 to 0.2 μm is formed, the refractive index is adjusted to the range of 1.55 to 2.30, and JIS
-The haze value measured in the state of being integrated with the base material in accordance with the regulation of K7361-1 is not different from the haze value of the base material only, or the difference from the haze value of the base material is suppressed within 10%. Is possible.

When the coating film obtained according to the present invention is adjusted to a film thickness of 0.2 to 20 μm, it is used as a hard coat layer such as an antireflection film which requires high transparency. can do. In particular, ultrafine particles of inorganic oxide having a high refractive index such as titanium oxide are mixed to obtain a refractive index of 1.
When the thickness is adjusted within the range of 55 to 2.30, it is possible to simplify the number of layers required to have antireflection performance. For example, by increasing the refractive index of the hard coat layer, a thin film having a layer structure of a high refractive index layer / a low refractive index layer should normally be formed on the hard coat layer in order to obtain antireflection performance. Since the same antireflection performance can be obtained only with the low refractive index layer, the manufacturing process can be simplified. According to the present invention, when the film thickness is 0.2 to 20 μm, the refractive index is adjusted to the range of 1.55 to 2.30, and the haze value defined in JIS-K7361-1 is
It is possible to suppress the difference between the haze value of the base material alone and the haze value of the base material within 20%.

The coating film obtained by the present invention is also suitably used as a conductive transparent thin film such as an antistatic layer provided on an antireflection film or a transparent conductive layer provided on a pixel driving element of a liquid crystal display device. be able to. According to the present invention, when the film thickness is 0.05 to 0.2 μm, JIS-K7
The haze value measured in the state of being integrated with the base material in accordance with the provisions of 361-1 is the same as the haze value of the base material only, or the difference from the haze value of the base material is within 10%. A thin film is obtained. Further, according to the present invention, when the film thickness is 0.2 to 20 μm, the haze value specified in JIS-K7361-1 does not differ from the haze value of the base material only, or the haze value of the base material only. A conductive transparent thin film having a difference of 20% or less is obtained. When the coating film obtained by the present invention is added to the antireflection film as a conductive transparent thin film such as an antistatic layer, the coating film obtained by the present invention can only be added as a simple conductive transparent thin film to the antireflection film. Alternatively, it may be added as a layer which also functions as a low, medium or high refractive index layer constituting the antireflection film. When the coating film obtained by the present invention is added to the antireflection film as a mere conductive transparent thin film, the same side as the antireflection film of the substrate film supporting the antireflection film is provided,
Alternatively, the conductive transparent thin film may be provided on either side of the opposite side.

Next, a specific example of the functional film to which the coating film according to the present invention is applied will be described. First, an antireflection film to which the coating film according to the present invention is applied will be described. The coating film according to the present invention is used to form one layer of a multi-layered antireflection film formed by laminating two or more layers (light transmitting layers) having light transmittance and different refractive indexes from each other. You can The coating film according to the present invention is mainly used as a medium to high refractive index layer, but can also be used as a high refractive index hard coat layer, a low refractive index layer and an antistatic layer. In the multilayer antireflection film, the layer having the highest refractive index is referred to as a high refractive index layer, the layer having the lowest refractive index is referred to as a low refractive index layer, and a layer having an intermediate refractive index other than that is It is called a medium refractive index layer.

Further, even if only one coating film according to the present invention is provided on the surface coated with the antireflection film, for example, the display surface of the image display device, the refractive index of the coating surface itself and the coating film according to the present invention can be improved. An antireflection effect can be obtained when the refractive index is well balanced. Therefore, the coating film according to the present invention may function effectively as a single-layer antireflection film.

The coating film according to the present invention is applied to the display surface of an image display device such as a liquid crystal display device (LCD), a cathode ray tube display device (CRT), a plasma display panel (PDP) or an electroluminescence display (ELD). It is preferably used for forming at least one layer of the multi-layered antireflection film to be coated, particularly a medium to high refractive index layer.

FIG. 1 schematically shows a cross section of an example (101) of a liquid crystal display device in which the display surface is covered with a multilayer antireflection film containing the coating film according to the present invention as a light transmitting layer. . The liquid crystal display device 101 prepares a color filter 4 formed by forming an RGB pixel portion 2 (2R, 2G, 2B) and a black matrix layer 3 on one surface of a glass substrate 1 on the display surface side, and a pixel of the color filter is prepared. The transparent electrode layer 5 is provided on the part 2, the transparent electrode layer 7 is provided on one surface of the glass substrate 6 on the backlight side, and the glass substrate on the backlight side and the color filter are arranged so that the transparent electrode layers 5 and 7 face each other. Then, they are opposed to each other with a predetermined gap therebetween, the periphery is adhered with a sealing material 8, the liquid crystal L is sealed in the gap, the alignment film 9 is formed on the outer surface of the glass substrate 6 on the back side, and the glass substrate on the display surface side is formed. The polarizing film 10 is attached to the outer surface of the display unit 1, and the backlight unit 11 is arranged behind the polarizing film 10. The transparent electrode layers 5 and 7 can also be composed of the coating film according to the present invention.

FIG. 2 schematically shows a cross section of the polarizing film 10 attached to the outer surface of the glass substrate 1 on the display surface side. In the polarizing film 10 on the display surface side, both surfaces of a polarizing element 12 made of polyvinyl alcohol (PVA) or the like are covered with protective films 13 and 14 made of triacetyl cellulose (TAC) or the like, and an adhesive layer 15 is provided on the back surface side. The hard coat layer 16 and the multilayer antireflection film 17 are sequentially formed on the viewing side, and the hard coat layer 16 and the multilayer antireflection film 17 are attached to the glass substrate 1 on the display surface side via the adhesive layer 15.

Here, in order to reduce the glare by diffusing light emitted from the inside as in a liquid crystal display device or the like, the hard coat layer 16 has the surface of the hard coat layer formed in an uneven shape, or An inorganic or organic filler may be dispersed inside the hard coat layer to provide an antiglare layer (antiglare layer) having a function of scattering light inside the hard coat layer.

The multilayer antireflection film 17 has a three-layer structure in which a middle refractive index layer 18, a high refractive index layer 19 and a low refractive index layer 20 are sequentially laminated from the backlight side to the viewing side. ing. The multilayer antireflection film 17 may have a two-layer structure in which a high refractive index layer 19 and a low refractive index layer 20 are sequentially stacked. When the surface of the hard coat layer 16 is formed in an uneven shape, the multilayer antireflection film 17 formed thereon also has an uneven shape as illustrated.

The low refractive index layer 20 may be formed by blending a composite in which fine particles of an inorganic oxide having a low refractive index are combined with the coating film according to the present invention. Alternatively, silica or silica may be used. A coating film having a refractive index of 1.46 or less obtained from a coating liquid containing an inorganic substance such as magnesium fluoride or a fluororesin, or a chemical vapor deposition method (CVD) or a physical vapor deposition method (PVD) of silica or magnesium fluoride. ) And the like can be used for the vapor deposition film. In addition, the medium refractive index layer 1
8 and the high refractive index layer 19 can be formed by blending a composite in which fine particles of an inorganic oxide having a high refractive index such as titanium oxide are bonded to the coating film according to the present invention. A light transmitting layer having a refractive index of 1.46 to 1.80 is used for 18, and a light transmitting layer having a refractive index of 1.65 or more is used for the high refractive index layer 19.

By the action of this antireflection film, the reflectance of the light emitted from the external light source is reduced, so that the reflection of scenery and fluorescent lamps is reduced and the visibility of the display is improved. In addition, when external light is reflected on the display surface or glares, the reflected light of external light is reduced by the light scattering effect of the unevenness of the hard coat layer 16, and the visibility of the display is further improved. .

In the case of the liquid crystal display device 101, the coating composition according to the present invention is applied to a laminate composed of the polarizing element 12 and the protective films 13 and 14 to have a refractive index of 1.46.
It is possible to form the medium refractive index layer 18 adjusted in the range of 1.80 to 1.80, the high refractive index layer 19 adjusted to the refractive index of 1.65 or more, and further provide the low refractive index layer 20. Then, the polarizing film 10 including the antireflection film 17 can be attached to the viewing-side glass substrate 1 via the adhesive layer 15.

On the other hand, since the orientation plate is not attached to the display surface of the CRT, it is necessary to directly provide the antireflection film.
However, applying the coating composition according to the present invention to the display surface of a CRT is a complicated task. In such a case, an antireflection film containing the coating film according to the present invention is produced, and the antireflection film is formed by adhering it to the display surface, so that the display surface is coated with the antireflection film according to the present invention. No need to apply the composition.

At least one of the light-transmitting layers is formed by laminating two or more light-transmitting layers having light-transmitting properties and different refractive indexes on one surface or both surfaces of the light-transmitting substrate film. An antireflection film can be obtained by forming one of the coating films according to the present invention. The base film and the light-transmitting layer need to have a light-transmitting property such that they can be used as a material for the antireflection film, and those that are as transparent as possible are preferable.

FIG. 3 schematically shows a cross section of an example (102) of an antireflection film containing a coating film according to the present invention. The antireflection film 102 is formed by coating the coating composition according to the present invention on one surface side of the base film 21 having light transmittance to form the high refractive index layer 22, and further forming the low refractive index layer on the high refractive index layer. The refractive index layer 23 is provided. In this example, the light transmitting layers having different refractive indexes are only two layers, that is, the high refractive index layer and the low refractive index layer, but three or more light transmitting layers may be provided. In that case, not only the high refractive index layer but also the medium refractive index layer can be formed by applying the coating composition according to the present invention.

As a specific example to which the coating film according to the present invention can be applied other than the antireflection film, there is a transparent conductive film. Figure 4
[Fig. 2] is a schematic view of a cross section of an example (103) of a transparent conductive film containing a coating film according to the present invention. The transparent conductive film 103 is a base film 2 having optical transparency.
1. The coating composition according to the present invention is applied to one side of the conductive transparent thin film 24 to be used as an antistatic film when the conductivity of the conductive transparent thin film is relatively small. When the conductivity is relatively high, it can be used as a transparent conductive film such as a transparent electrode film. When the coating composition according to the present invention cannot be directly applied to a place where a conductive transparent thin film is desired to be formed, such a transparent conductive film 103 is prepared, and a transparent or conductive film is attached or installed at a necessary place to obtain a conductive film. The function of the transparent thin film can be exerted.

Further, in the transparent conductive film 103 of FIG. 4, the coating composition of the present invention containing a composite in which conductive inorganic oxide fine particles are bonded is applied to one side of the base film 21 in a relatively thick thickness. It is also possible to obtain a hard coat film by forming a hard coat layer having an antistatic function.

[0143]

EXAMPLES Example 1 (1) Bonding of Polymer to Titanium Oxide Ultrafine Particle Surface As a rutile type titanium oxide, the titanium oxide content is 76-8.
Surface treatment with Al ₂ O ₃ at 3%, primary particle size 0.01-
A rutile titanium oxide (TTO51 (A), manufactured by Ishihara Sangyo Co., Ltd.) having a surface area of 0.03 μm, a specific surface area of 75 to 85 m ² / g, an oil absorption amount of 40 to 47 g / 100 g, and a hydrophilic surface was prepared. In addition, polymethylmethacrylate (HA-6, Toagosei Co., Ltd.) having a number average molecular weight of 6,000 and hydroxyl groups at both ends was prepared as a reactive polymer having a reactive group at the terminal. Methyl isobutyl ketone was prepared as the organic solvent.

10.0 g of the reactive polymer, 40.0 g of methyl isobutyl ketone, and 5.0 g of rutile-type titanium oxide were placed in a mayonnaise bottle, and about 4 times the amount of the mixture was used as a medium for a paint shaker. The mixture was shaken for 3 hours to obtain a dispersion liquid. The obtained dispersion was transferred to a flask equipped with a cooling tube and stirred at 100 ° C. for 5 hours to covalently bond a part of the reactive polymer to rutile type titanium oxide. After the reaction was completed, the reaction solution was placed in a centrifuge, the ultrafine particles were allowed to settle, the supernatant was removed, and methyl isobutyl ketone was added again to perform ultrasonic treatment.
The process of centrifuging after redispersing the ultrafine particles was repeated until no polymer component could be confirmed in the supernatant after sedimentation of the ultrafine particles.

The washed rutile-type titanium oxide ultrafine particles were dried at room temperature under reduced pressure to obtain polymer-bonded titanium oxide ultrafine particles. The amount of the polymer bound to the surface of the ultrafine particles was 8% by weight based on the amount of the polymer thermally decomposed by thermogravimetric analysis.

(2) Preparation of coating composition Among the components in the following amounts, rutile type titanium oxide, pentaerythritol triacrylate, dispersant, and methyl isobutyl ketone were placed in a mayonnaise bottle, and about 4 parts of the mixture were mixed.
After using a double amount of zirconia beads (φ0.3 mm) as a medium and shaking with a paint shaker for 10 hours, a photoinitiator was added to obtain a coating composition having the following composition.

<Composition of coating composition> -Rutile type titanium oxide to which polymethacrylic acid is bound:
10 parts by weight pentaerythritol triacrylate (PET3
0, manufactured by Nippon Kayaku Co., Ltd .: 4 parts by weight anionic group-containing dispersant (Disperseick 163,
Big Chemie Japan Co., Ltd .: 0.5 parts by weight Photoinitiator (Irgacure 184, Ciba Specialty Chemicals Co., Ltd.): 0.2 parts by weight Methyl isobutyl ketone: 35 parts by weight (2) Coating Preparation of film and evaluation of physical properties (a) Formation of coating film 1 Triacetyl cellulose film (FT) having a thickness of 80 μm
-T80UZ, thickness of 3 on Fuji Photo Film Co., Ltd.
After forming a pentaerythritol triacrylate cured film having a thickness of μm, the coating composition immediately after preparation was applied with a bar coater # 2, dried by heating at 60 ° C. for 1 minute, and then 5
It was cured by UV irradiation of 00 mJ to form a transparent film having a thickness of 0.1 μm after curing.

With respect to this transparent film, the film strength and the deposited film adhesion were evaluated by the following tests.

(Film Strength) The film strength was evaluated by changing the haze when rubbing the surface of the film 20 times with a load of 200 g to 1 kg using # 0000 steel wool.

(Adhesiveness with evaporated film) PVD under the following conditions
A silica vapor deposition film having a thickness of 84.7 μm was formed by the method, and the following cellophane tape cross-cut peeling test was performed on the obtained vapor deposition film <PVD method conditions> -Target for thermal vapor deposition: silicon monoxide (purity 99. 9
%) ・ Output: current value 0.4 A, voltage 480 V ・ Vacuum degree in vacuum chamber: 0.13 Pa ・ Argon flow rate: 38.8 sccm ・ Oxygen flow rate: 5 sccm ・ Evaporation rate: 8.47 nm / min <cellophane tape grid pattern Peeling test conditions> 10 vertical and 10 horizontal scratches were made on the surface of the coating film with a cutter at right angles and 1
00 grid-like grids were provided. The cellophane tape was strongly adhered from above, and it was peeled off at once, and the number of squares left on the film surface was counted.

(Test Results) The results of each test are shown in Table 1. In the film strength test, it was confirmed that the transparent film was not scratched at a load of 1 kg. In addition, this transparent film
In the cellophane tape cross-cut peeling test, the silica film was not peeled at all and showed good adhesion to the deposited film.

(2) Formation of coating film 2 For the measurement of haze and refractive index, a coating composition immediately after preparation was prepared on a surface-untreated PET substrate (Lumina T60 manufactured by Toray Industries, Inc.) having a thickness of 50 μm. Bar coater # 2
Coating, heat drying at 60 ° C for 1 minute, then 500mJ
Cured by UV irradiation, and the film thickness after curing is 0.1 μm
Of transparent film was formed.

The coating composition was allowed to stand at room temperature for 30 days to observe the occurrence of precipitation, and the coating composition after standing was used to give a thickness of 50 μm as described above.
Untreated PET base material (Luminor T6 manufactured by Toray Industries, Inc.)
A transparent film having a thickness of 0.1 μm after curing was formed on 0).

Haze and refractive index were measured by the following methods for transparent films having a film thickness after curing of 0.1 μm formed from the coating compositions immediately after preparation and after being left at room temperature. (Haze) Haze was measured using a turbidimeter NDH2000 (manufactured by Nippon Denshoku Industries Co., Ltd.).

(Refractive Index) The refractive index of the coating film after curing was measured by using a spectroscopic ellipsometer (UVSEL, manufactured by Jobin-Evon Co.) at a wavelength of 633 nm of helium laser light.

(Test Results) Table 2 shows the results of each test. When the coating composition prepared in Example 1 was used, the coating film had a haze of 0.1 and a refractive index of 1.92.
Therefore, a transparent film having good haze and refractive index was obtained. Further, the coating composition of Example 1 was excellent in dispersibility even after being left at room temperature, and a transparent film having good haze and refractive index was obtained similarly to immediately after preparation.

Example 2 As a reactive polymer, polydimethylsiloxane having hydroxyl groups at both ends (KF-60) was used.
02, manufactured by Shin-Etsu Chemical Co., Ltd., was carried out in the same manner as in Example 1 to bond the reactive polymer to the surface of the titanium oxide ultrafine particles. The amount of polymer bound to the surface of the ultrafine particles was 11% by weight according to thermogravimetric analysis.

Thereafter, as the polymer-grafted ultrafine particles, the same procedure as in Example 1 was carried out except that the above-mentioned titanium oxide ultrafine particles to which polydimethylsiloxane was bonded was used and that the anionic group-containing dispersant was not used. ,
A coating composition was obtained.

Coating films 1 and 2 were prepared in the same manner as in Example 1 by using the obtained coating composition, and the physical properties were evaluated. The test results are shown in Tables 1 and 2. In the film strength test, it was confirmed that the transparent film prepared from the coating composition of Example 2 had no scratches under a load of 1 kg. Further, this transparent film did not peel the silica film at all in the cellophane tape cross-cut peeling test, and showed good adhesion to the deposited film. The haze and refractive index of the transparent film prepared from the coating composition of Example 2 were 0.1 and 1.94, respectively, and a transparent film having good haze and refractive index was obtained. Further, the coating composition of Example 2 was excellent in dispersibility even after being left at room temperature, and a transparent film having good haze and refractive index was obtained similarly to immediately after preparation.

Therefore, although the coating composition of Example 2 did not use the anionic polar group-containing dispersant, it had the same film strength, deposited film adhesion, haze, and refractive index as in Example 1. It was good. The coating composition of Example 2 was able to have a higher refractive index than that of Example 1 because no dispersant was used.

Comparative Example 1 Instead of the reactive polymer,
The same procedure as in Example 1 was carried out except that polymethylmethacrylate (manufactured by Junsei Chemical Co., Ltd.) having a number average molecular weight of 6,000 and no hydroxyl groups at both ends was used, but the polymer was bound to rutile titanium oxide. I couldn't let you do it.

Thereafter, a coating composition was prepared in the same manner as in Example 1 except that the rutile type titanium oxide ultrafine particles having no polymer bonded were used instead of the polymer graft ultrafine particles. A coating film 1 and a coating film 2 were prepared in the same manner as in Example 1 using the coating composition thus prepared, and the physical properties were evaluated.

The test results are shown in Tables 1 and 2. A coating film was formed using the coating composition of Comparative Example 1 immediately after the preparation, but the uniformity was poor for the ultrafine particles to which the polymer was not bound because the amount of the dispersant was too small, as shown in Table 1. Moreover, the film strength and the adhesion of the deposited film were poor. Further, the coating film obtained from the coating composition of Comparative Example 1 had a high haze as shown in Table 2 and the coating film was clouded, so that it was impossible to accurately measure the refractive index. In addition, a large amount of precipitate was generated when left at room temperature. The haze measurement after standing at room temperature was omitted because a large amount of precipitate was generated.

[0164]

[Table 1]

[0165]

[Table 2]

[0166]

Industrial Applicability As described above, the composite according to the present invention and the coating composition in which the composite is mixed can be used to form the inorganic oxide fine particles even if the dispersant is not used at all or only in a small amount. It is possible to form a transparent film having excellent dispersibility and dispersion stability and having a small haze imparted with some function (for example, a predetermined refractive index or conductivity) due to the physical properties of the inorganic oxide fine particles.

Further, the coating composition according to the present invention is excellent in coating suitability, can easily form a uniform large-area thin film, and can form a transparent film with a controlled refractive index and a small haze at a low cost. Suitable for mass production.

The coating film of the present invention is formed by using the coating composition of the present invention. Since this coating film has high transparency and a small haze, and the function and performance can be adjusted by controlling the compounding amount of the inorganic oxide fine particles, it can be used as various functional transparent thin films. Typically, an optical thin film such as a low refractive index layer of an antireflection film, a medium to high refractive index layer or a high refractive index hard coat layer, an antistatic film, an antistatic hard coat layer, a transparent electrode film, etc. It can be suitably used for forming a conductive transparent thin film.

Further, when the binder component of the coating film according to the present invention has a hydrogen bond-forming group, the adhesiveness to the adjacent layer, especially to the vapor deposition layer is particularly excellent.

The antireflection film containing the coating film according to the present invention is preferably applied to the display surface of a liquid crystal display device, a CRT or the like.

[Brief description of drawings]

FIG. 1 is an example of a liquid crystal display device in which a display surface is covered with a multilayer antireflection film including a coating film according to the present invention, and a diagram schematically showing a cross section thereof.

FIG. 2 is a diagram schematically showing a cross section of an example of an alignment plate provided with a multilayer antireflection film including a coating film according to the present invention.

FIG. 3 is an example of an antireflection film including a coating film according to the present invention, and is a diagram schematically showing a cross section thereof.

FIG. 4 is a diagram schematically showing a cross section of an example of a transparent conductive film including a coating film according to the present invention.

[Explanation of symbols]

101 ... Liquid crystal display device 102 ... Antireflection film 1 ... Glass substrate on display side 2 ... Pixel part 3 ... Black matrix layer 4 ... Color filter 5, 7 ... Transparent electrode layer 6 ... Glass substrate on the back side 8 ... Sealing material 9 ... Alignment film 10 ... Polarizing film 11 ... Backlight unit 12 ... Polarizing element 13, 14 ... Protective film 15 ... Adhesive layer 16 ... Hard coat layer 17 ... Multilayer antireflection film 18 ... Middle refractive index layer 19 ... High refractive index layer 20 ... Low refractive index layer 21 ... Base film 22 ... High refractive index layer 23 ... Low refractive index layer 24 ... Conductive transparent thin film

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08G 77/398 C08G 77/398 4J038 C09C 1/00 C09C 1/00 3/06 3/06 3/12 3 / 12 C09D 4/00 C09D 4/00 201/00 201/00 G02B 1/11 G02B 1/10 AF term (reference) 2K009 AA02 AA04 AA05 AA15 CC01 CC02 CC03 CC09 CC21 CC24 DD02 DD05 DD06 EE03 4F100 AA17C AA21C AA25CAA AA28C AA29C AK25C AT00A BA03 BA04 BA07 BA10C BA10D CA23C CA23H CC00D CC02C GB41 JB14C JN01A JN01B JN01C JN06 JN18B JN18C 4J026 BA02 BA03 BA05 BA06 BA07 BA30 DB30 BA04 BA30 BA40 BA04 BA30 BA40 BA31 BA32 BA31 BA32 BA31 BA32 BA31 BA32 BA31 BA32 BA31 BA32 BA31 CA05U CA052 CA09U CA092 CA11U CA112 CA18U CA182 CA28M CA29M FB02 FB10 LA05 LB01 4J037 AA08 AA11 AA22 AA25 AA30 CA08 CA12 CA24 CA30 CC12 CC28 DD04 DD05 EE02 EE11 FF15 FF23 4J038 FA111 HA166 HA216 KA08 NA20 PB08

Claims (36)

[Claims] 1. A number average molecular weight of 2,000 to 20,0.
A polymer portion having a polymer structure of 00, and 0.01 to
A composite, which is characterized by being covalently bonded to inorganic oxide fine particles having a primary particle diameter in the range of 0.1 μm. 2. The inorganic oxide fine particles are titania,
Zirconia, zinc oxide, tin oxide, cerium oxide, antimony oxide, tin-doped indium oxide (IT
O), antimony-doped tin oxide (ATO), zinc-doped indium oxide (IZO), aluminum-doped zinc oxide (AZO), and fluorine-doped tin oxide (FTO). The composite according to claim 1, characterized in that 3. The inorganic compound particles according to claim 1, wherein at least a part of the surface of the inorganic compound particles is coated with an inorganic compound that reduces or eliminates the photocatalytic activity of the inorganic compound particles. The described complex. 4. The inorganic compound is alumina, silica,
Zinc oxide, zirconium oxide, tin oxide, tin oxide doped with antimony (ATO), indium oxide doped with tin (ITO), indium oxide doped with zinc (IZO), zinc oxide doped with aluminum (A
ZO) and fluorine-doped tin oxide (FTO)
The composite body according to claim 3, wherein the composite body is selected from the group consisting of: 5. The titania fine particles whose surface is at least partially coated with an inorganic compound that reduces or eliminates photocatalytic activity, according to any one of claims 2 to 4. Complex of. 6. The composite according to claim 1, wherein the polymer portion is an α, β-ethylenically unsaturated monomer-based polymer and / or a polysiloxane-based polymer. 7. The composite according to claim 1, which is used as a material for an optical thin film. 8. At least (1) said claim 1 thru | or 7
A coating composition comprising the composite according to any one of the above, (2) a binder component, and (3) an organic solvent. 9. The coating composition according to claim 8, wherein the binder component is a photocurable binder component. 10. The coating composition according to claim 8 or 9, wherein the binder component is a binder component having an anionic polar group in the molecule. 11. The coating composition according to claim 10, wherein the anionic polar group of the binder component is a hydrogen bond-forming group. 12. The coating composition according to claim 11, wherein the hydrogen bond-forming group of the binder component is a hydroxyl group. 13. The binder component having a hydroxyl group in the molecule is pentaerythritol polyfunctional acrylate,
13. The coating composition according to claim 12, wherein the coating composition is one or more components selected from the group consisting of dipentaerythritol polyfunctional acrylate, pentaerythritol polyfunctional methacrylate, and dipentaerythritol polyfunctional methacrylate. . 14. The binder component having an anionic polar group in the molecule is contained in an amount of 4 to 20 parts by weight based on 10 parts by weight of the inorganic oxide fine particles. The coating composition according to any one of 1 to 13. 15. The binder component having an anionic polar group in the molecule is contained in an amount of 4 to 40 parts by weight based on 10 to 20 parts by weight of the inorganic oxide fine particles. Item 14. The coating composition according to any one of items 8 to 13. 16. The coating composition according to claim 8, wherein the organic solvent is a ketone solvent. 17. The method according to claim 8, wherein the organic solvent is mixed in a proportion of 50 to 99.5 parts by weight based on 0.5 to 50 parts by weight of the total solid content. The coating composition according to. 18. The coating composition according to claim 8, which is used for forming an optical thin film. 19. The coating composition according to claim 14, which is used for forming a medium refractive index layer, a high refractive index layer or a conductive transparent thin film of an antireflection film. 20. The coating composition according to claim 15, which is used for forming a high refractive index hard coat layer of an antireflection film. 21. Obtained by applying the coating composition according to any one of claims 8 to 20 to the surface of an article to be coated, and when the film thickness is 0.05 to 0.2 μm, the refractive index is 1.55 to 2.30 and JIS-K736
The haze value specified in 1-1 does not differ from the haze value of the base material only, or the difference from the haze value of the base material is 1
A coating film characterized by being within 0%. 22. It is obtained by applying the coating composition according to any one of claims 8 to 20 to the surface of an article to be coated, and when the film thickness is 0.2 to 20 μm, the refractive index is 1. 55 to 2.30 and JIS-K7361-
The haze value specified in 1 does not differ from the haze value of the base material only, or the difference from the haze value of the base material is 20%.
A coating film characterized by being within. 23. A number average molecular weight of 2,000 to 20,
Polymer part having a polymer structure of 000 and 0.01 to
The composite obtained by covalently bonding the inorganic oxide fine particles having a primary particle diameter in the range of 0.1 μm is uniformly mixed in the binder, and when the film thickness is 0.05 to 0.2 μm, Rate is 1.55
To 2.30, and the haze value specified in JIS-K7361-1 does not differ from the haze value of the base material only, or the difference from the haze value of the base material is within 10%. Yes, a coating film. 24. A number average molecular weight of 2,000 to 20,
Polymer part having a polymer structure of 000 and 0.01 to
The composite obtained by covalently bonding the inorganic oxide fine particles having a primary particle diameter in the range of 0.1 μm is uniformly mixed in the binder, and when the film thickness is 0.2 to 20 μm, the refractive index is 1.55-
2.30, and the haze value specified in JIS-K7361-1 does not differ from the haze value of the base material only, or the difference from the haze value of the base material is within 20%. And the coating film. 25. The inorganic oxide fine particles are titania, zirconia, zinc oxide, tin oxide, cerium oxide, antimony oxide, tin-doped indium oxide (IT).
O), antimony-doped tin oxide (ATO), zinc-doped indium oxide (IZO), aluminum-doped zinc oxide (AZO), and fluorine-doped tin oxide (FTO). The coating film according to claim 23 or 24, wherein 26. Any one of claims 23 to 25, characterized in that at least a part of the surface of the inorganic oxide fine particles is coated with an inorganic compound that reduces or eliminates the photocatalytic activity of the inorganic oxide fine particles. The coating film according to Crab. 27. The inorganic compound is alumina, silica, zinc oxide, zirconium oxide, tin oxide, tin oxide doped with antimony (ATO), indium oxide doped with tin (ITO), indium oxide doped with zinc. (IZO), aluminum-doped zinc oxide (AZO), and fluorine-doped tin oxide (FT)
The coating film according to claim 26, which is selected from the group consisting of O). 28. The titania fine particles whose surface is at least partially coated with an inorganic compound that reduces or eliminates photocatalytic activity, according to any one of claims 23 to 27. Paint film. 29. The method according to claim 23, wherein the polymer portion is an α, β-ethylenically unsaturated monomer-based polymer and / or a polysiloxane-based polymer.
7. The coating film according to any one of 7. 30. The binder comprises one or more components selected from the group consisting of pentaerythritol polyfunctional acrylate, dipentaerythritol polyfunctional acrylate, pentaerythritol polyfunctional methacrylate, and dipentaerythritol polyfunctional methacrylate. The coating film according to any one of claims 23 to 29, which is a product. 31. The light-transmitting layer having a light-transmitting property and different in refractive index from each other, wherein two or more light-transmitting layers are laminated, and at least one of the light-transmitting layers is defined in any one of claims 23 to 30. An antireflection film, which is a coating film. 32. A light-transmitting layer formed by dry coating is further formed adjacent to the coating film according to claim 23.
The antireflection film according to claim 31. 33. Two or more light-transmitting layers having light-transmitting properties and different refractive indexes are laminated on at least one surface side of a light-transmitting substrate film, At least one is the coating film in any one of the said Claims 23 thru | or 30, The antireflection film characterized by the above-mentioned. 34. A light-transmitting layer formed by dry coating is further formed adjacent to the coating film according to any one of claims 23 to 30.
The antireflection film according to claim 33. 35. An image display device having a display surface covered with an antireflection film, wherein the antireflection film is formed by laminating two or more light transmitting layers having light transmitting properties and different refractive indexes from each other. An image display device, wherein at least one of the light transmitting layers is the coating film according to any one of claims 23 to 30. 36. A light transmission layer formed by dry coating is further formed adjacent to the coating film according to any one of claims 23 to 30.
The antireflection film according to claim 35.