JP5138280B2 - Black material, black material dispersion, black light-shielding film, and substrate with black light-shielding film - Google Patents

Description

  The present invention relates to a black material, a black material dispersion, a black light-shielding film, and a substrate with a black light-shielding film, and more specifically, a black material excellent in blackness, heat resistance and light shielding properties, and inexpensive. The present invention relates to a black material dispersion liquid dispersed in a dispersion medium, a black light shielding film produced using the black material dispersion liquid, and a substrate with a black light shielding film provided with the black light shielding film.

Conventionally, black materials are black light shielding films, black light shielding glasses, black matrix materials, black seal materials, black mask materials for flat panel displays (FPD) such as plasma display (PDP) and liquid crystal display (LCD). For example, it is used as a material that imparts black color or light shielding properties.
As such a black material, silver fine particles and silver tin alloy fine particles are known (Patent Documents 1 and 2).
JP 2004-240039 A JP 2006-89771 A

However, although the conventional black material is excellent in light-shielding properties, it is expensive because it contains a high content of noble metals, and therefore is not suitable for general-purpose products. It was.
In particular, when silver fine particles are actually used, it is rarely used as a powder and is used as a silver fine particle dispersion in which silver fine particles are dispersed in a dispersion medium. Although it has excellent light shielding properties, silver is a noble metal and is expensive, and the coating film is difficult to be applied to general-purpose products as a black material because it becomes a reflective film after drying. There was a problem.

Therefore, the present inventors have proposed the following black material (Japanese Patent Application No. 2006-134805).
This black material has an average particle diameter of 1 nm to 200 nm and contains copper tin alloy fine particles in which two or more kinds of spherical fine particles, plate-shaped fine particles, cubic fine particles, and rod-shaped fine particles are mixed.
However, although the black material containing the copper-tin alloy fine particles has high blackness and excellent light shielding properties, the properties are easily deteriorated by the heat treatment when forming the black light shielding film, and the black material has sufficient light shielding properties. There is still a problem to be solved that a light shielding film cannot be obtained.

  The present invention has been made in order to solve the above problems, and is a black material excellent in blackness, heat resistance and light shielding properties, a black material dispersion liquid in which the black material is dispersed in a dispersion medium, It is an object of the present invention to provide a black light shielding film produced using this black material dispersion and a substrate with a black light shielding film provided with the black light shielding film.

  As a result of intensive studies on black materials that can improve the respective properties of blackness, heat resistance, and light shielding properties, the present inventors have found that if copper tin alloy fine particles and silver tin alloy fine particles are mixed, black As a result, it was found that a black material excellent in temperature, heat resistance and light shielding properties was obtained, and it was cheaper than noble metals such as silver fine particles, and the present invention was completed.

That is, the black material of the present invention comprises a mixture of a copper-tin alloy particles and the silver-tin alloy particles, the average primary particle size of copper-tin alloy fine particles and a silver-tin alloy particle is Ri der more and 200nm or less 1 nm, The copper content in the copper tin alloy fine particles is 1 wt% or more and 50 wt% or less, and the silver content in the silver tin alloy fine particles is 30 wt% or more and 90 wt% or less. .
Alloy phase of the copper-tin alloy _{particulates, CuSn,} Cu _{3 Sn,} the group of _{Cu 4 Sn, Cu 6.26 Sn 5} , Cu 10 Sn 3, Cu 40.5 Sn 11, Cu 41 Sn 11, Cu 81 Sn 22 It is preferable that it is 1 type or multiple types of alloy phases selected from these.
The alloy phase of the silver-tin alloy fine particles is preferably an alloy phase represented by Ag _x Sn (where 3 ≦ x ≦ 4).

The black material dispersion of the present invention is characterized in that the black material of the present invention is dispersed in a dispersion medium.
The black light-shielding film of the present invention is characterized in that the black material dispersion of the present invention is applied on one main surface of a substrate and heat-treated.
The base material with a black light-shielding film of the present invention is characterized by comprising the black light-shielding film of the present invention on one main surface of the base material.

According to the black material of the present invention, to mix and copper-tin alloy particles and the silver-tin alloy particles, the average primary particle size of copper-tin alloy particles and silver-tin alloy particle and 1nm or more and 200nm or less, further, the copper Since the copper content in the tin alloy fine particles is 1 wt% or more and 50 wt% or less, and the silver content in the silver tin alloy fine particles is 30 wt% or more and 90 wt% or less , the blackness, heat resistance and light Excellent shielding properties.

The best mode for carrying out the black material, the black material dispersion, the black light shielding film, and the substrate with the black light shielding film of the present invention will be described.
This embodiment is specifically described for better understanding of the gist of the invention, and does not limit the present invention unless otherwise specified.

"Black material"
The black material of this embodiment is a black material formed by mixing copper tin alloy fine particles and silver tin alloy fine particles.
The alloy phase of the copper tin alloy fine particles may be a single phase copper tin alloy phase represented by Cu _x Sn _y , or may be a plurality of different types of copper tin alloy phases.
Examples of the alloy phase represented by Cu _x Sn _y include CuSn, Cu ₃ Sn, Cu ₄ Sn, Cu _6.26 Sn ₅ , Cu ₁₀ Sn ₃ , Cu _40.5 Sn ₁₁ , Cu ₄₁ Sn ₁₁ , Cu ₈₁ Sn ₂₂ or the like is preferable.

Further, as the silver tin alloy fine particles, when expressed by the chemical formula Ag _x Sn, the range of x in which a chemically stable silver tin alloy can be obtained is 1 ≦ x ≦ 10. The range of x at which degrees can be obtained simultaneously is 3 ≦ x ≦ 4.
In this black fine particle, the range of x may be in the range of 1 ≦ x ≦ 10. However, in order to obtain chemical stability and blackness at the same time, the range of x may be 3 ≦ x ≦ 4. preferable.
This black material may contain silver fine particles in addition to copper tin alloy fine particles and silver tin alloy fine particles to such an extent that the object of the present invention is not impaired.

The content of copper in the black material is preferably 1% by weight or more and 50% by weight or less, more preferably 2% by weight or more and 30% by weight or less.
Here, the reason for limiting the copper content to the above range is that when the copper content is less than 1% by weight, the content of tin and silver is relatively high, and in particular, the content of tin is high. In this case, heat resistance and corrosion resistance are deteriorated, and when the silver content is high, the reflectance becomes high, and a coating film having sufficient blackness cannot be obtained. This is because if the content exceeds 50% by weight, the heat resistance of the copper-tin alloy fine particles is not sufficiently satisfied, and the light shielding property tends to be lowered during the heat treatment of the coating film.

Further, the silver content in the black material is preferably 30% by weight or more and 90% by weight or less, more preferably 40% by weight or more and 80% by weight or less.
Here, the reason why the silver content is limited to the above range is that when the silver content is less than 30% by weight, sufficient light shielding properties cannot be obtained, while the silver content is low. This is because if it exceeds 90% by weight, the reflectance of light becomes high, and a coating film having sufficient blackness cannot be obtained.

The average primary particle diameter of the black material is preferably 1 nm or more and 200 nm or less, more preferably 10 nm or more and 100 nm or less.
Here, the reason why the average primary particle size is limited to the above range is that a desired black light-shielding film can be easily formed by setting the average primary particle size within the above range. That is, if the average primary particle diameter is less than 1 nm, the amount of transmitted light increases because it is too small compared to the wavelength of visible light, and the desired blackness may not be obtained. If the thickness exceeds 200 nm, it may be difficult to obtain the desired blackness with the black light-shielding film.

  The black material is not particularly limited as long as it is a method capable of obtaining a black material in which copper tin alloy fine particles and silver tin alloy fine particles are mixed, and includes a gas phase reaction method, a spray pyrolysis method, an atomization method, a liquid It can be prepared using ordinary fine particle synthesis methods such as phase reaction method, freeze-drying method, hydrothermal synthesis method, etc. Especially, black material with copper tin alloy fine particles and silver tin alloy fine particles mixed is easy. It is preferable to use the obtained liquid phase reaction method.

As an example of the liquid phase reaction method, for example, a method in which a copper chelate compound solution is dropped into a tin colloidal dispersion and then a silver compound solution is appropriately applied can be exemplified.
The chelating agents contained in this copper chelate compound solution include formic acid, oxalic acid, succinic acid, tartaric acid, citric acid, ammonia, ethylenediamine, ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), triethylenetetramine hexaacetic acid ( TTHA), or one or more selected from the group of these salts can be used.

In this liquid phase reaction method, the synthesis is completed by a reaction in the liquid phase, so that it is not necessary to recover the black material, and the black material dispersion can be easily obtained.
Moreover, when producing a black light shielding film using this black material, in consideration of dispersibility with the photosensitive resin, the water dispersion system may be changed to an organic solvent dispersion system. When changing to an organic solvent dispersion system, cake-like agglomerates collected from the liquid phase are temporarily pulverized into powder, and then dispersed in an organic solvent using a wet mixer such as a ball mill or bead mill. The method to do is taken.

"Black material dispersion"
The black material dispersion of this embodiment is a dispersion in which the black material of this embodiment is dispersed in a dispersion medium.
The content of the black material in this dispersion is preferably 1% by weight or more and 80% by weight or less, more preferably 5% by weight or more and 50% by weight or less, and further preferably 10% by weight or more and 40% by weight or less. .
Here, the reason why the content of the black material is limited to 1% by weight or more and 80% by weight or less is that this range is a range in which the black material can take a good dispersion state, and the content is less than 1% by weight. This is because the effect as a black material is reduced, and when it exceeds 80% by weight, the concentration of the black material becomes too high to be in a paste state and the characteristics as a dispersion are lost.

The dispersion medium basically contains at least one of water, an organic solvent, a liquid resin monomer, and a liquid resin oligomer.
Examples of the organic solvent include alcohols such as methanol, ethanol, 2-propanol, butanol, and octanol, ethyl acetate, butyl acetate, ethyl lactate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and γ-butyrolactone. Esters such as diethyl ether, ethylene glycol monomethyl ether (methyl cellosolve), ethylene glycol monoethyl ether (ethyl cellosolve), ethylene glycol monobutyl ether (butyl cellosolve), ethers such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, acetone, Methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, cyclohexanone, etc. Amides, aromatic hydrocarbons such as benzene, toluene, xylene and ethylbenzene, and amides such as dimethylformamide, N, N-dimethylacetoacetamide and N-methylpyrrolidone are preferably used. One of these solvents or Two or more kinds can be used.

As the liquid resin monomer, acrylic or methacrylic monomers such as methyl acrylate and methyl methacrylate, and epoxy monomers are preferably used.
Moreover, as said liquid resin oligomer, a urethane acrylate oligomer, an epoxy acrylate oligomer, an acrylate oligomer, etc. are used suitably.

"Black light shielding film and substrate with black light shielding film"
The black light-shielding film of the present embodiment is a black film formed by applying the black material dispersion liquid of the present embodiment on one main surface of the base material and performing a heat treatment.
The base material with a black light shielding film of the present embodiment is provided with the black light shielding film of the present embodiment on the surface (one main surface) of the base material.

The black light-shielding film of the present embodiment is formed by, for example, appropriately mixing the above-described black material dispersion and a photosensitive resin, and applying the obtained mixture onto the substrate by various application methods to form a coating film. It can be easily obtained by heat-treating this coating film.
The temperature of this heat treatment is not particularly limited as long as the substrate can be extinguished, and for example, a heat treatment of about 3 minutes to 120 minutes at a temperature in the range of 80 ° C. to 300 ° C. in an air atmosphere is exemplified. Can do.

Since this black light-shielding film is obtained by applying a dispersion containing a black material in which copper tin alloy fine particles and silver tin alloy fine particles are mixed, the black light-shielding film has excellent blackness, heat resistance and light shielding properties.
By forming this black light-shielding film on a substrate such as a glass substrate, a substrate with a black light-shielding film can be easily obtained.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention concretely, this invention is not limited by these Examples.

"Example 1"
10 g of tin colloid (average primary particle size: 30 nm, solid content: 10% by weight, manufactured by Sumitomo Osaka Cement Co., Ltd.) was collected, and pure water was added thereto to prepare a tin colloid solution A having a total volume of 300 mL.
Further, 0.4 g of copper (II) sulfate pentahydrate (CuSO ₄ .5H ₂ O), 0.55 g of ethylenediaminetetraacetic acid (EDTA) dihydrate, and 0.6 g of 25% by weight aqueous sodium hydroxide solution were purified. Water was added to prepare a mixed solution B having a total weight of 50 g.
Furthermore, 2.5 mL of concentrated ammonia water (NH ₃ : 28 wt%) was added to 1.5 g of silver nitrate, and pure water was further added to prepare an aqueous silver nitrate solution C having a total weight of 50 g.

  Next, while stirring the tin colloid solution A, the mixed solution B was dropped into the tin colloid solution A, then the aqueous silver nitrate solution C was dropped, and further an acid was added to carry out a neutralization reaction. Next, washing was carried out by centrifugation to obtain a dispersion of Example 1 having a particle (solid content) concentration of 15% by weight.

When this dispersion was diluted with ethanol and the particles contained therein were observed with a transmission electron microscope (TEM), the particles had an average particle diameter of 40 nm.
The dispersion was filtered to separate particles, and the particles were dried to prepare a powder sample. The product phase in the powder sample was identified by a powder X-ray diffraction method.
Further, the content (% by weight) of copper, tin, and silver in the powder sample was measured by an electron beam microanalyzer (EPMA). These results are shown in Table 1.

  Next, an aqueous polyvinyl pyrodrine (PVP) solution was added to the dispersion so that the volume ratio of particles (solid content) to polyvinyl pyrodrine (PVP) was 25:75, and an ultrasonic disperser (Sonifier 450, BRANSON ULTRASONIC Co.) and left to stand for 1 hour to obtain a coating solution.

Next, a coating film was formed by spin coating on a glass substrate having a size of 10 cm × 10 cm × 2 mm using this coating solution. Here, the thickness of the coating film was set to 0.6 μm by adjusting the amount of water in the coating solution.
Next, after drying at 100 ° C. for 3 minutes using a dryer, the substrate was further heat-treated at 240 ° C. for 1 hour to produce the black light-shielding film-coated substrate of Example 1.

Subsequently, the light shielding property of this black light shielding film was evaluated.
First, the optical density (OD value) of the black light-shielding film after drying at 100 ° C. for 3 minutes was measured using a transmission densitometer, and the optical density of the black light-shielding film after heat treatment at 240 ° C. for 60 minutes. (OD value) was measured in the same manner.
In addition, the thickness of the black light-shielding film after heat treatment at 240 ° C. is measured with a film thickness meter Tencor (manufactured by Tencor), and the reflectance of the black light-shielding film itself with respect to light having a wavelength of 500 nm is measured with a spectrophotometer. did.
These results are shown in Table 1.

"Example 2"
Pure water was added to 1.8 g of copper (II) sulfate pentahydrate (CuSO ₄ .5H ₂ O), 2.8 g of ethylenediaminetetraacetic acid (EDTA) dihydrate, and 3 g of 25% by weight sodium hydroxide aqueous solution, A mixed solution D having a total weight of 50 g was prepared.
Next, while stirring the colloidal tin solution A used in Example 1, the mixed solution D was dropped into the colloidal tin solution A. Next, washing was performed by centrifugation to prepare a mixed solution E.
Next, while stirring the mixed solution E, the aqueous silver nitrate solution C used in Example 1 was added dropwise to the mixed solution E, and an acid was added to carry out a neutralization reaction. Next, washing was carried out by centrifugation to obtain a dispersion of Example 2 having a particle (solid content) concentration of 15% by weight.

When this dispersion was diluted with ethanol and the particles contained therein were observed with a transmission electron microscope (TEM), the particles had an average particle diameter of 40 nm.
The dispersion was filtered to separate particles, and the particles were dried to prepare a powder sample. The product phase in the powder sample was identified by a powder X-ray diffraction method.
Further, the content (% by weight) of copper, tin, and silver in the powder sample was measured by an electron beam microanalyzer (EPMA). These results are shown in Table 1.

Subsequently, the coating liquid of Example 2 was obtained in the same manner as in Example 1 except that the dispersion liquid of Example 2 was used. Further, a black light-shielding film-coated substrate of Example 2 was produced in the same manner as in Example 1 except that the coating solution of Example 2 was used. Further, the light shielding property of the black light shielding film of Example 2 was evaluated in the same manner as in Example 1.
These results are shown in Table 1.

"Comparative example"
200 g of tin colloid (average primary particle 30 nm, solid content 10 wt%, manufactured by Sumitomo Osaka Cement) was mixed with 2000 g of pure water to prepare a mixed solution F.
Moreover, 3000 g of pure water was added to 50 g of copper (II) sulfate pentahydrate (CuSO ₄ .5H ₂ O) and 70 g of ethylenediaminetetraacetic acid (EDTA) dihydrate to prepare a mixed solution G.
Next, the mixed solution G was fed to the mixed solution F and stirred, and further diluted nitric acid was added to carry out a neutralization reaction, whereby a dispersion of Comparative Example 2 was obtained.

When this dispersion was diluted with ethanol and the particles contained therein were observed with a transmission electron microscope (TEM), the particles had an average particle diameter of 40 nm.
The dispersion was filtered to separate particles, and the particles were dried to prepare a powder sample. The product phase in the powder sample was identified by a powder X-ray diffraction method.
Further, the content (% by weight) of copper, tin, and silver in the powder sample was measured by an electron beam microanalyzer (EPMA). These results are shown in Table 1.

Subsequently, the coating liquid of the comparative example was obtained in the same manner as in Example 1 except that the dispersion liquid of this comparative example was used. Further, a base material with a black light-shielding film of a comparative example was produced in the same manner as in Example 1 except that the coating liquid of this comparative example was used. Further, the light shielding property of the black light shielding film of this comparative example was evaluated in the same manner as in Example 1.
These results are shown in Table 1.

According to Table 1, the produced phase in the powder samples of Examples 1 and 2 was a mixture of copper tin alloy, silver tin alloy and silver. On the other hand, the produced phase in the powder sample of the comparative example was only a copper-tin alloy.
Further, in the black light shielding films of Examples 1 and 2, there was no change in the optical density of the black light shielding film after drying at 100 ° C. and the black light shielding film after heat treatment at 240 ° C., whereas in the black light shielding film of the comparative example, The optical density of the black light-shielding film after heat treatment at 240 ° C. was lower than the optical density of the black light-shielding film after drying at 100 ° C. From this, it was found that the black light shielding films of Examples 1 and 2 were superior in blackness, heat resistance and light shielding properties as compared with the black light shielding film of the comparative example.

  Since the black material of the present invention is mixed with copper tin alloy fine particles and silver tin alloy fine particles, it is excellent in blackness, heat resistance, and light shielding properties, and is inexpensive compared with noble metals such as silver, Of course black matrix materials, black seal materials, black mask materials, black shielding films, black shielding glass, black ink, etc. for flat panel displays (FPD) such as plasma displays (PDP) and liquid crystal displays (LCD) In particular, it can be applied to a black matrix material that requires heat treatment at a high temperature when producing a black light-shielding film.

Claims (6)

Combining copper tin alloy fine particles and silver tin alloy fine particles,
The average primary particle size of copper-tin alloy fine particles and a silver-tin alloy particle is Ri der more and 200nm or less 1 nm,
The copper content in the copper tin alloy fine particles is 1 wt% or more and 50 wt% or less,
A black material, wherein a silver content in the silver-tin alloy fine particles is 30% by weight or more and 90% by weight or less . The alloy phase of the copper tin alloy fine particles is CuSn, Cu ₃ Sn, Cu ₄ Sn, Cu _6.26 Sn ₅ , Cu ₁₀ Sn ₃ , Cu _40.5 Sn ₁₁ , Cu ₄₁ Sn ₁₁ , Cu ₈₁ Sn ₂₂ The black material according to claim 1, wherein the black material is one or a plurality of alloy phases selected from the group consisting of: The alloy phase of the silver-tin alloy fine particles is Ag. _x The black material according to claim 1, wherein the black material is an alloy phase represented by Sn (where 3 ≦ x ≦ 4).   A black material dispersion comprising the black material according to claim 1 dispersed in a dispersion medium.   A black light-shielding film obtained by applying the black material dispersion liquid according to claim 4 onto one main surface of a base material and heat-treating it.   A base material with a black light-shielding film, comprising the black light-shielding film according to claim 5 on one main surface of the base material.