JPH05117552A - Coating for forming high refractive index antistatic film and transparent material laminate having high refractive index antistatic film - Google Patents

Abstract

PURPOSE:To obtain the subject coating consisting of an aqueous dispersion containing a mixture of antimony-doped tin oxide fine powder and specific binder, having excellent antistatic property and capable of readily and inexpensively forming a coating film excellent in adhesion to a film layer having low refractive index. CONSTITUTION:The objective coating consisting of an aqueous dispersion containing a mixture of (A) fine powder of antimony-doped tin oxide and (B) silicone oil (preferably amino-modified silicone oil) as a binder of the component A. A ratio of content of the component A and content (expressed in terms of SiO2 of the component B is preferably (80-99.99):(20:0.01). An amount of antimony doped into the component A is 1-5wt.%, based on weight of tin oxide. Furthermore, water is preferably used as a solvent of the aqueous dispersion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antistatic / high refractive index film-forming coating material and an antistatic / high refractive index film-attached transparent material laminate obtained by using the same. More specifically, the present invention relates to the display surface of a display device, its surface cover material, window glass, show window glass, TV cathode ray tube display surface, liquid crystal device display surface, instrument cover glass, watch cover. Antistatic / high refractive index film forming paint useful for coating the surface of transparent materials such as glass and the front image surface of CRT which are required to prevent static electrification and reflection, and to obtain using it The present invention relates to an antistatic / high refractive index film-attached transparent material laminate.

[0002]

2. Description of the Related Art Generally, transparent materials for displaying images, such as TVs.
It is known that static electricity is easily charged in the image display portion of the cathode ray tube, and that the static electricity causes dust to adhere to the display surface. In addition, there are known problems such that external light is reflected on the image display surface or an external image is transferred, and the image on the display surface is unclear.

In order to solve the above problems, conventionally, a non-aqueous solvent dispersion of fine particles of antimony-doped tin oxide and a hydrolysis product of silicon alkoxide is applied to the surface of a transparent substrate, Drying is performed to form an antistatic film layer, and a film layer having a lower refractive index than that is formed on the antistatic film. This low refractive index film layer is
It is usually formed by the hydrolysis product of silicon alkoxide, namely silica. However, the adhesion between the conventional antistatic film layer and the low refractive index film layer is poor,
There is a problem that delamination easily occurs between these two layers.

Further, the refractive index of the conventional antistatic film layer is about n = 1.50 to 1.54, and as described above, a hydrolysis product (silica) of silicon alkoxide.
The difference from the refractive index of the low refractive index film layer formed by the above is small, and therefore, the antireflection property of the conventional combination of the antistatic film layer and the low refractive index film layer was insufficient. Furthermore, in the conventional antistatic film layer, a silicon alkoxide is used as a binder of antimony-doped tin oxide fine powder, and when this silicon alkoxide is brought into contact with a large amount of water, hydrolysis and polycondensation are promoted and insoluble Since it produces silica and loses its function as a coating material at an early stage, it is necessary to use a non-aqueous solvent (generally ethyl alcohol) for the coating material for forming an antistatic film layer. However, in order to reduce the cost of the paint, prevent environmental pollution, and facilitate handling, it is desirable to use water as the paint solvent.

In order to solve the above-mentioned problems, as described above, charging is carried out from a paint comprising a non-aqueous solvent dispersion liquid containing a mixture of antimony-doped tin oxide fine powder and a hydrolysis product (silica) of silicon alkoxide. Forming a barrier layer,
Attempts were also made to form a low-refractive index film layer by applying a paint consisting of an aqueous dispersion of a hydrolyzate of silicon alkoxide (silica) on it, but the adhesion between the two layers obtained was not satisfactory. It was sufficient, the antireflection effect was insufficient, and the life of the paint was short, so that it could not be put to practical use.

[0006]

SUMMARY OF THE INVENTION The present invention provides a low refractive index film layer having excellent antistatic properties on a transparent material surface.
Antistatic / high-refractive-index film-forming coating that is useful for easily and inexpensively forming a film layer with good adhesion using water as a solvent, and antistatic / high-refractive index obtained using it An object of the present invention is to provide a transparent material laminate having an index film, particularly a transparent material laminate having an antistatic / high refractive index film layer and a low refractive index film layer formed thereon.

[0007]

The present invention can solve the above problems by using silicone oil instead of silicon alkoxide as a binder for antimony-doped tin oxide fine powder, instead of using silicon alkoxide. It was completed based on the headline.

That is, the coating composition for forming an antistatic / high refractive index film according to the present invention is characterized by comprising an aqueous dispersion containing a mixture of antimony-doped tin oxide fine powder and silicone oil. Is.

The coating composition of the present invention may further contain a colorant having an absorption center wavelength near 600 nm. The content of the colorant in the paint is 3 to 2 relative to the weight of the solid content of the paint.
It is preferably 0%.

The antistatic / high refractive index film-attached transparent material laminate according to the present invention comprises a transparent base material, and a fine powder of antimony-doped tin oxide and a silicone oil on the surface of the transparent base material. An antistatic / high-refractive-index film layer formed by applying and drying a paint composed of an aqueous dispersion containing a mixture, and a layer formed on the antistatic / high-refractive-index film layer and having a refractive index of 0 or more And a low refractive index film layer having a low refractive index of 1 or more.

The transparent material laminate of the present invention may be colored with a coloring agent having an absorption center wavelength in the vicinity of 600 nm, whereby a filter function is imparted. This colorant is added to at least one of the high refractive index film layer and the low refractive index film layer. The colorant content in the high refractive index film layer is preferably 3 to 20% by weight, and the colorant content in the low refractive index film layer can be appropriately determined.

[0012]

[Function] The antistatic / high refractive index film-forming coating material of the present invention,
In the antimony-doped tin oxide fine powder-silicone oil mixture used, the ratio of the content of the antimony-doped tin oxide fine powder to the content of the silicone oil (converted to SiO ₂ ) is 80 to 99.99: 20 to 0.01. Is preferred. The total weight of the mixture with the content of antimony-doped tin oxide fine powder (the amount of silicone oil is Si
When the ratio to O ₂ is less than 80/20,
The content of silicone oil becomes excessive, and the mechanical strength of the obtained membrane layer becomes insufficient. Moreover, it is 99.9.
When it is more than 9 / 0.01, the content of silicone oil becomes too small, and the adhesiveness with other materials of the obtained antistatic / high refractive index film layer, that is, with the transparent substrate or with the low refractive index film layer. Becomes insufficient.

In the conventional antistatic coating composition containing silicon alkoxide, the content of the antimony-doped tin oxide fine powder is the same as that of silicon alkoxide (SiO 2).
It was generally less than 80% by weight based on the total weight (converted to ₂ ). This is because the content of antimony-doped tin oxide fine powder and that of silicon alkoxide (SiO 2
This is because if the amount is 80% by weight or more based on the total weight of the mixture with ( ₂ conversion), the dispersibility of the antimony-doped tin oxide fine powder is reduced and a uniform coating layer cannot be formed.

However, in the present invention, the use of silicone oil has made it possible to incorporate antimony-doped tin oxide fine powder into the coating material at a content of 80% by weight or more. Therefore, the antistatic / high refractive index film layer obtained using the coating composition of the present invention not only exhibits extremely excellent antistatic effect and electromagnetic wave shielding effect,
It is possible to have a high refractive index of n = 1.55 to 2.0. Therefore, the refractive index (generally n = 1.45 or less) of the low refractive index film layer formed thereon,
It is possible to make the difference from the refractive index of the antistatic / high refractive index film layer 0.1 or more, preferably 0.15 or more,
Therefore, the combination of the antistatic / high refractive index film layer and the low refractive index film layer obtained by the present invention exhibits excellent antireflection property.

That is, the reflected light from the surface of the low refractive index film layer can be canceled by the interference of the reflected light from the interface between the antistatic / high refractive index film layer having a high refractive index and the low refractive index film layer. Therefore, the antireflection effect can be enhanced more than ever before. In the antimony-doped tin oxide fine powder used in the present invention, tin oxide can be obtained by vapor phase method, CVD
Method, hydrothermal method, carbonate method and the like may be used. The shape of the fine particles is not particularly limited, and may be spherical, needle-like, plate-like, chain-like or the like.

The method of doping antimony with respect to tin oxide and the amount of antimony doped are not particularly limited, but generally 1 to 5 relative to the weight of tin oxide.
% Is preferable. As a result, the tin oxide fine powder can further enhance its antistatic effect, electromagnetic wave shielding effect, and the like. The antimony-doped tin oxide fine powder used in the present invention preferably has an average particle diameter of 1 to 100 nm. If the average particle size is less than 1 nm, the electrical conductivity is reduced and the particles are easily aggregated, making it difficult to uniformly disperse the particles in the coating.
The viscosity of the coating increases, and it is necessary to add a large amount of a dispersion solvent to reduce the viscosity, which may result in an excessively low concentration of antimony-doped tin oxide fine powder in the coating.

When the average particle size of the antimony-doped tin oxide fine powder is larger than 100 nm, in the obtained antistatic / high refractive index film layer, light is remarkably diffused due to Rayleigh scattering to make it appear white and its transparency is high. descend. The silicone oil used in the present invention is also not particularly limited, but amino group, carboxyl group,
It is desirable that the organosiloxane compound has at least one hydrophilic group selected from an epoxy group, a hydroxyl group, a polyether group, an ester group, an alkoxy group and the like, and is not hydrolyzed by an aqueous solvent. As such an organosiloxane compound, amino-modified silicone oil, carboxy-modified silicone oil, epoxy-modified silicone oil, hydroxyl group silicone oil, polyether-modified silicone oil, ester-modified silicone oil, and alkoxy-modified silicone oil can be used. ..

It is preferable to use water as the solvent, but the solvent compatible with water is 6% based on the total weight of the solvent.
It may be mixed with water in an addition amount of 0 weight or less.

In the laminate of the present invention, the thickness or weight of the antistatic / high refractive index film layer formed on the transparent substrate is not particularly limited, but is generally 0.05 to 0.2 μm. It is preferable to have. A low refractive index film layer is formed on the antistatic / high refractive index film layer formed using the coating material of the present invention. The low refractive index film layer is effective for filling voids on the surface of the antistatic / high refractive index film layer, suppressing irregular reflection, and improving its abrasion resistance.

The low-refractive index film layer can be formed by coating and drying a coating material composed of a non-aqueous solvent solution containing a silicon alkoxide on the antistatic / high-refractive index film layer and subjecting it to baking treatment. The silicon alkoxide used in the low refractive index film layer-forming coating material can be selected from tetraalkoxysilane-based compounds, alkyltrialkoxysilane-based compounds, dialkyldialkoxysilane-based compounds, and the non-aqueous solvent is alcohol-based. It can be selected from compounds, glycol ether compounds, ester compounds, ketone compounds and the like. These may be used alone or as a mixture of two or more.

When the above coating material is applied onto the antistatic / high refractive index film layer, dried and baked, the silicon alkoxide hydrolysis product becomes silica. The refractive index of silica is n = 1.46, which is lower than that of antimony-doped tin oxide, but to increase the difference in refractive index between the antistatic / high refractive index film layer and the low refractive index film layer. Is preferably used in combination with a substance having a lower refractive index than silica and high transparency.

In the present invention, it is preferable that the coating composition containing silicon alkoxide further contains fine powder of magnesium fluoride (n = 1.38). There is no particular limitation on the content of the magnesium fluoride fine powder in the low refractive index film layer, and it can be appropriately handled depending on the composition of the corresponding antistatic / high refractive index film layer, but in general, 0.01 to the weight of silicon alkoxide (converted to SiO ₂ )
It is preferably in the range of 50%.

The magnesium fluoride fine powder used for forming the low refractive index film layer preferably has an average particle diameter of 1 to 100 nm. If the average particle size is larger than 100 nm, in the resulting low refractive index film layer, light may be diffusely reflected by Rayleigh number scattering, the low refractive index film layer may appear whitish, and its transparency may deteriorate. Is 1
If it is less than nm, the fine particles are likely to coagulate, so that it becomes difficult to uniformly disperse the fine particles in the coating material, resulting in problems such as an excessive viscosity of the coating material. In addition, when the amount of the solvent used is increased in order to reduce the viscosity of the coating material, there arises a problem that the concentrations of the magnesium fluoride fine powder and the silicon alkoxide in the coating material are reduced.

The magnesium fluoride fine powder used in the present invention can be produced by a gas phase method (gasifying the compound, cooling this in the gas phase to solidify), a CVD method (gasifying the component elements, and And the product is cooled and solidified), a carbonate (or oxalate) method (a carbonate of the metal element or an oxalate is transformed in a gas phase, and solidified by cooling) by a known method. It can be manufactured. In addition, an acid-alkali method of producing an ultrafine particle sol of a target compound by mixing and reacting an aqueous solution of a fluoride of a component element with an aqueous solution of a basic compound, or a hydrothermal method of removing a solvent therefrom is a method of producing magnesium fluoride fine particles. It can be used for the production of powders. In the above hydrothermal method, growth of fine particles, spheroidization,
Alternatively, the surface can be modified. The shape of the fine particles may be any of spherical, needle-like, plate-like, chain-like and the like.

In the present invention, the thickness of the low refractive index film layer is not particularly limited, but it is preferably 0.05 to 0.2 nm. Since the low refractive index film layer having a thickness in the above range is relatively thin, even if it covers the antistatic / high refractive index film layer, the conductivity of the antistatic / high refractive index film layer is reduced. Due to the property, it is possible to exhibit a practically sufficient antistatic property and electromagnetic wave shielding property as a whole.

The transparent substrate used in the present invention can be selected from glass materials, plastic materials and the like. Further, the colorant used in the present invention can be appropriately selected from those conventionally used for the material and the coating material.

[0027]

The present invention will be further described with reference to the following examples.

Example 1 (1) A coating material (A) for forming an antistatic / high refractive index film layer was prepared as follows. That is, 2.8 g of antimony-doped tin oxide fine powder (Sumitomo Cement Co., Ltd., particle size: 5
10 nm) and 0.3 g (converted to SiO ₂ ) of polyether-modified silicone oil (silicone surfactant, trademark:
L-77, manufactured by Nippon Unicar Co., Ltd.) was mixed with 196.4 g of water, and the mixture was stirred to form a uniform dispersion liquid.

(2) A coating material (a) for forming a low refractive index film layer was prepared by the following procedure. That is, 0.8 g of tetraethoxysilane, 0.8 g of 0.1N hydrochloric acid, and 9
A uniform solution was prepared by mixing with 9.2 g of ethyl alcohol. (3) Manufacture of Laminated Body The above coating material (A) was applied onto one surface of a glass substrate at a temperature of 40 ° C. by a spin coating method, and dried with warm air of 50 ° C. for 3 minutes. An antistatic high refractive index film layer having a thickness of 0.1 μm was formed. Next, the coating material (a) was applied on the antistatic / high-refractive index film layer of this glass substrate at a temperature of 40 ° C. by a spin coating method, and the temperature was increased to 50 ° C.
Was dried with warm air and baked at 150 ° C. for 20 minutes to form a low refractive index film layer having a thickness of 0.1 μm.

(4) Test Surface resistivity (by surface resistance meter) and surface reflectance (wavelength by spectrophotometer using specular reflection jig with incident angle of 5 degrees) of the transparent material laminate obtained as described above. The single-sided value of the light reflectance at 550 nm was measured.) And the adhesion between the antistatic / high refractive index film layer and the low refractive index film layer (eraser test, load 1 kg, 50 times reciprocation) was measured. The test results are shown in Table 1.

Example 2 The same operation as in Example 1 was performed. However, instead of the low refractive index film layer-forming coating material (a), the coating material (b) prepared as described below was used. That is, 0.4 g of magnesium fluoride fine powder (Sumitomo Cement Co., Ltd., particle size: 10 to 20 nm) was added to 0.6 g of tetraethoxysilane, 10 g of water, 0.6
g 0.1 N hydrochloric acid and 89 g ethyl alcohol were mixed and uniformly dispersed. The test results are shown in Table 1.

Example 3 The same operation as in Example 1 was performed. However, instead of the low refractive index film-forming coating material (a), the coating material (c) prepared as described below was used. That is, the specific wavelength selective absorption / low refractive index film layer forming coating material (c) was prepared as follows. 0.
After mixing 8 g of tetraethoxysilane and 0.8 g of 0.1N hydrochloric acid with 98.9 g of ethyl alcohol, a coloring agent (Chganol Violet3BN 33% manufactured by Chugai Kasei Co., Ltd., Acid
Green V conc. 5% and Kayanol Millin manufactured by Nippon Kayaku Co., Ltd.
g Red 6BW 52% and Neo Super Bl manufactured by Chuo Gosei Kagaku KK
ue C-551 10% mixture) 0.3 g was added and stirred to give a uniform solution. Table 1 shows the test results
Shown in.

Comparative Example 1 The same operation as in Example 1 was performed. However, the antistatic
Instead of the high refractive index film layer-forming coating material (A), the coating material (B) prepared as described below was used. That is, 1 g of antimony-doped tin oxide (particle size 5 to 10 nm) was mixed with 1.68 g of tetraethoxysilane, 4.1 g of 0.1N hydrochloric acid, and 143 g of ethyl alcohol, and uniformly dispersed. The test results are shown in Table 1.

Comparative Example 2 The same operation as in Example 1 was performed. However, instead of the antistatic / high refractive index film layer-forming coating material (A), a coating material (C) prepared as follows was used. That is, 2 g of antimony-doped tin oxide (particle size 5 to 10 nm) was added to 1.1
g of silicone oil and 196.4 g of water were mixed and uniformly dispersed. The test results are shown in Table 1.

[0035]

[Table 1]

[0036]

The coating composition for forming an antistatic / high refractive index film according to the present invention is a film having excellent antistatic property, high refractive index, and excellent adhesion to a low refractive index film layer on a transparent substrate. A layer that can be easily and inexpensively formed by using water as a solvent, and in particular, an antistatic / high refractive index film layer obtained by using the low refractive index film is obtained. By combining the layers, it is possible to provide a transparent material laminate with an antistatic and high refractive index film, which has excellent practical performance.

Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location C09D 5/00 PPT PSD 6904-4J 183/04 PMT 8319-4J // C08L 83:00

Claims (10)

[Claims] 1. An antistatic coating for forming a high refractive index film, which comprises an aqueous dispersion containing a mixture of antimony-doped tin oxide fine powder and silicone oil. 2. The mixture is composed of 80 to 99.99 parts by weight of antimony-doped tin oxide fine powder and 0.01 to 20 parts by weight of silicone oil in terms of SiO ₂ .
The paint according to claim 1. 3. The antimony-doped tin oxide fine powder is 1
The coating composition of claim 1 having an average particle size of -100 nm. 4. The silicone oil comprises an amino group, a carboxyl group, an epoxy group, a hydroxyl group, a polyether group,
The coating material according to claim 1, which is selected from organosiloxane compounds having at least one selected from an ester group and an alkoxy group. 5. The paint according to claim 1, further comprising a colorant having an absorption center wavelength near 600 nm. 6. A transparent substrate and a surface of the transparent substrate,
Antistatic / high refractive index film layer formed by applying and drying a paint consisting of an aqueous dispersion containing a mixture of antimony-doped tin oxide fine powder and silicone oil, and this antistatic / high refractive index film layer A transparent material laminated body with an antistatic / antireflection film, which comprises a low refractive index film layer formed on the above and having a refractive index lower than the refractive index by 0.1 or more. 7. The low-refractive index film layer is formed by applying a coating material containing a silicon alkoxide and a non-aqueous solvent on the antistatic / high-refractive index film layer, drying the coating, and baking the coating. The transparent material laminate according to claim 5, wherein 8. The transparent material laminate according to claim 6, wherein the coating material containing a silicon alkoxide-non-aqueous solvent further contains fine particles of magnesium fluoride dispersed therein. 9. The magnesium fluoride fine powder is 1 to 1
The transparent material laminate according to claim 7, which has an average particle diameter of 00 nm. 10. The transparent material laminate according to any one of claims 6, 7, 8 and 9, which is colored with a coloring agent having an absorption center wavelength near 600 nm and thereby has a filter function.