JP2012167194A - Black material, black material dispersed liquid, black resin composition, black film, and base material coated with the black film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a black material having a low reflectivity relative to a visible light ray, high blackness, and an excellent light shading property, of which absorbance in a visible light region has small wavelength dependency, and capable of obtaining a black film having natural color tone; a black material dispersed liquid using the black material; a black coating; a black light shading film; and a base material coated with a black film having the black light shading film.SOLUTION: This black material is a black material containing metal fine particles containing fine particles containing at least a silver element and a tin element in which: the content of the silver element is 30 mass% or more and 99 mass% or less; the metal fine particles have an average primary particle diameter corresponding to the circle diameter of 3 nm or more and 100 nm or less; the dispersion produced by dispersing the black material in a dispersion medium so that the solid content in the dispersion becomes 0.0005 volume% has an average absorbance from 380 nm to 800 nm in a light path length of 10 mm of 0.8 or more; and the ratio d/dof an absorbance dat 420 nm with an absorbance dat 680 nm is 0.6 or more and 2.5 or less.

Description

  The present invention relates to a black material, a black material dispersion using the black material, a black resin composition, a black film, and a substrate with a black film.

  Conventionally, black materials include black light-shielding film, black light-shielding glass, black paper, black cloth, black ink, plasma display panel (PDP), liquid crystal display (LCD), and organic electroluminescence (EL) display. It is used as a material that imparts black color or light-shielding properties to black matrix materials, black seal materials, black mask materials, and the like of display elements.

As such a black material, silver fine particles are known in addition to metal materials and inorganic materials such as carbon black, titanium black (low-order titanium oxide or titanium oxynitride), iron oxide, and chromium (for example, Patent Documents). 1).
When a black light-shielding film is produced using a black material composed of the above-mentioned silver fine particles, this black material is excellent in light-shielding properties, but has a metallic color and a color due to plasmon absorption. There is a problem that it is high and cannot exhibit excellent blackness.

  In order to remedy this problem, the molar absorption at the minimum value of the spectral absorption spectrum in the visible spectral wavelength range of 400 to 700 nm is obtained by adopting a connected form in which metal fine particles are randomly connected as spherical particles in the dispersion. A black dispersion having a coefficient of 1800 L / mol · cm or more has been proposed (see, for example, Patent Document 2).

  On the other hand, the present inventors have already proposed a black material composed of silver tin alloy fine particles (for example, see Patent Documents 3 and 4). The black material composed of the silver-tin alloy fine particles can form a black light-shielding film having low visible light reflectance, excellent blackness, and excellent light shielding properties.

JP 2004-240039 A JP 2008-003150 A JP 2006-087771 A JP 2006-227268 A

  However, the black light-shielding films obtained by these known techniques have a large wavelength dependency of the absorbance in the visible light region, so when the black light-shielding film is viewed with transmitted light, the film has a color such as brown or reddish brown. In transmission densitometers that use spectral filters with different wavelength dependencies when measuring the light-shielding properties of the film with a transmission densitometer, it is difficult to obtain a tasteful and natural color tone. There was a problem that different measured values could be obtained.

  The present invention has been made in view of such a situation, and has a low visible light reflectance, high blackness, excellent light shielding properties, small wavelength dependency of absorbance in the visible light region, and natural black tone. It aims at providing the black material from which a film | membrane is obtained, the black material dispersion liquid using this black material, a black resin composition, a black film, and the base material with a black film which has this black film.

The above problems are solved by the present invention described below. That is, the present invention
[1] It is composed of metal fine particles including fine particles containing at least silver element and tin element, the silver element content is 30% by mass or more and 99% by mass or less, and the average primary particle diameter corresponding to the circle diameter of the metal fine particles Is a black material having a thickness of 3 nm to 100 nm,
In the dispersion liquid in which the black material is dispersed so that the solid content is 0.0005% by volume in the dispersion medium, the average absorbance from 380 nm to 800 nm at an optical path length of 10 mm is 0.8 or more, and the absorbance at 420 nm. black material ratio d ₄₂₀ / d ₆₈₀ between the absorbance d ₆₈₀ in the d ₄₂₀ and 680nm is 0.6 to 2.5,
[2] The metal fine particles include fine particles having a silver-tin alloy portion, mixed fine particles of fine particles having a silver-tin alloy portion and silver fine particles, mixed fine particles of fine particles having a silver-tin alloy portion and tin fine particles, and a silver-tin alloy portion. The black material according to [1], which is any one of a mixed fine particle of silver fine particles and tin fine particles, and a mixed fine particle of silver fine particles and tin fine particles,
[3] A black material dispersion in which the black material according to [1] or [2] is dispersed in a dispersion medium,
[4] The black material dispersion liquid according to [3], wherein an average dispersed particle diameter of the black material is 5 nm or more and 100 nm or less, and a 90% cumulative volume particle diameter is 1 μm or less,
[5] A black resin composition comprising at least the black material according to [1] or [2] and a resin forming component or a resin component,
[6] A black film containing at least the black material according to [1] or [2] and a resin component,
[7] Black film base according to [6] having a volume resistivity of 10 ¹¹ Ω · cm or more, and a base with black film having the black film according to [8] [6] or [7] on the substrate surface Material,
Is to provide.

  According to the present invention, a black material that has a low visible light reflectance, a high blackness, excellent light shielding properties, a small wavelength dependency of absorbance in the visible light region, and a natural color tone black film can be obtained. And a black material dispersion using the black material, a black resin composition, a black film, and a substrate with a black film having the black film.

It is a spectral absorption spectrum of the dispersion liquid which disperse | distributed the black material obtained in Example 1. FIG. It is a spectral absorption spectrum of the dispersion liquid which disperse | distributed the black material obtained by the comparative example 1.

Hereinafter, the present invention will be described with reference to embodiments. This embodiment is specifically described in order to better explain the gist of the invention, and does not limit the present invention unless otherwise specified.
<Black material>
The black material of the present embodiment is composed of metal fine particles including fine particles containing at least silver element and tin element, the silver element content is 30% by mass or more and 99% by mass or less, and average primary particles corresponding to a circle diameter. The diameter is 3 nm or more and 100 nm or less.

  In metal fine particles, it is known that the wavelength at which metal fine particles absorb light changes by controlling the particle size and particle shape, and the wavelength dependence of absorbance in the visible light region by combining fine particles with different absorption wavelengths May be reduced. However, generally known metals such as gold, silver, and copper that have plasmon absorption in the visible light region can reduce the wavelength dependence of absorbance while maintaining high light shielding properties and blackness only by controlling the particle diameter and particle shape. I couldn't. For example, silver fine particles having a small particle diameter have plasmon absorption around 420 nm, and the absorbance varies greatly depending on the wavelength. As the particle size of the silver fine particles increases, the absorbance spectrum in the visible light region becomes flat and the wavelength dependence decreases, but the particle size is too large to disperse the particles sufficiently and the light shielding property decreases. There is a problem that the appearance becomes whitish due to scattering of particles and the blackness is lowered.

  In the present embodiment, by utilizing tin that has a small wavelength dependency of absorbance in the visible light region, the characteristics that the light shielding property and blackness are high and the wavelength dependency of absorbance in the visible light region is small are simultaneously realized. I was able to. The content range of the silver element in the metal fine particles determined from this viewpoint is the first requirement.

If the content of silver element in the black material is less than 30% by mass, the proportion of tin in the black material will increase, and there will be sufficient light shielding properties if there is a part that is heated during the black film manufacturing process. Can't get. This is because tin has a melting point of 230 ° C., and at temperatures close to that, tin is oxidized to become tin oxide having a low blackness, resulting in a decrease in blackness.
On the other hand, if the content of the silver element in the black material exceeds 99% by mass, the reflectivity increases due to the silver element, and sufficient blackness cannot be obtained, or the wavelength dependence of the absorbance in the visible light region. May become larger and natural black color may not be obtained.
In addition, when the black material is made of only silver, when the black film is baked at 200 ° C. or higher in the atmosphere, the transmittance near 550 nm, which is the central region of visible light, is higher than that before baking, and the light shielding property is reduced. For this reason, it is not preferable that the black material is formed only of silver if there is a portion where heat is applied during the manufacturing process of the black film. Also from this viewpoint, it is necessary that the content of the silver element in the black material is 99% by mass or less.
45 mass% or more and 99 mass% or less are preferable, as for content of the silver element in the said black material, 60 mass% or more and 98 mass% or less are more preferable, and 70 mass% or more and 95 mass% or less are more preferable.

The content of the silver element in the black material may be obtained by performing a wet quantitative analysis such as ICP emission analysis on a solution in which the black material is dissolved with an acid or the like. Since it is only tin and does not contain a light element, it can be measured by EPMA (electron beam microanalyzer) analysis using a green compact. Since the metal elements that are the main components of the black material of this embodiment are only silver and tin, the content (%) of the silver element in the metal fine particles can be obtained from the measured value of EPMA by the following formula (1). it can.
Content of silver element (%) = [mass of silver element / (mass of silver element + mass of tin element)] × 100 (1)
Note that the denominator in the formula (1) does not include elements other than metals such as carbon resulting from a dispersant or the like adhering to the periphery of metal fine particles or oxygen due to oxidation of the surface of the metal fine particles. .

  As a second requirement, the average primary particle diameter corresponding to the circular diameter of the metal fine particles in the black material dispersion liquid needs to be 3 nm or more and 100 nm or less. By setting the average primary particle diameter within this range, a desired black shielding film can be easily formed. That is, when the average primary particle diameter is less than 3 nm, the amount of transmitted light is increased and the desired blackness may not be obtained because it is too small compared to the wavelength of visible light. On the other hand, if the average primary particle size exceeds 100 nm, scattering may occur and it may be difficult to obtain a desired blackness, or the unevenness of the surface of the black light shielding film may be increased.

The average primary particle size is preferably 3 nm to 60 nm, more preferably 5 nm to 60 nm, and still more preferably 5 nm to 40 nm.
In addition, the average primary particle diameter corresponding to the circle diameter in the present embodiment means that the metal fine particles having various shapes are observed with a TEM (transmission electron microscope) as described later, and the area is the same as the confirmed fine particles. The diameter corresponding to such a circle.

  That is, the configuration of the metal fine particles in the present embodiment includes fine particles having a silver-tin alloy part, mixed fine particles of fine particles having a silver-tin alloy part and silver fine particles, mixed fine particles of fine particles having a silver-tin alloy part and tin fine particles, silver One of fine particles having a tin alloy part, mixed fine particles of silver fine particles and tin fine particles, and mixed fine particles of silver fine particles and tin fine particles, and the average primary particle diameter corresponding to the circle diameter of these metal fine particles is 3 nm or more It is preferable that it is 100 nm or less. The silver tin alloy part will be described later.

Moreover, it is preferable that the black material in this embodiment contains the fine particle which has a silver tin alloy part. Here, the “silver-tin alloy part” includes an intermetallic compound of silver and tin, that is, includes a portion having a crystal structure different from the crystal structure of silver or tin. The portion where tin is solid-solved in a state where the silver crystal structure is maintained in silver (hereinafter also referred to as “tin-soluble silver”), or the solid solution of silver is maintained in the state where the tin crystal structure is maintained in tin. (Hereinafter also referred to as “silver solute tin”). The “fine particles having a silver-tin alloy part” are not only fine particles composed of only the silver-tin alloy part as described later, but also a composite with other metal parts having a silver-tin alloy part in part. Means containing fine particles.
Since the metal fine particles include a silver-tin alloy part in this manner, the movement of electrons is more inhibited than the case of a single metal due to the effect of scattering (an action that inhibits the movement of electrons) caused by alloying. The reflectance of the film can be reduced.

From this point of view, the configuration of the metal fine particles in the present embodiment includes fine particles having a silver-tin alloy part, mixed fine particles having a silver-tin alloy part and fine silver particles, and mixed fine particles having fine particles having a silver-tin alloy part and tin fine particles. The fine particles having a silver-tin alloy portion and mixed fine particles of silver fine particles and tin fine particles are preferable. Here, the silver fine particles are fine particles made only of silver substantially not containing tin, and the tin fine particles are fine particles made only of tin substantially not containing silver.
The fine particles having a silver-tin alloy portion are fine particles in which one particle is composed of only a silver-tin alloy portion, fine particles in which a silver-tin alloy portion and a silver portion are combined, and a composite of a silver-tin alloy portion and a tin portion. And fine particles in which a silver tin alloy part, a silver part and a tin part are combined. Here, a silver part is a part which consists only of silver which does not contain tin substantially, and a tin part is a part which consists only of tin which does not contain silver substantially.
Thus, by including fine particles having a silver-tin alloy part in the metal fine particles, it is possible to obtain a good balance between light shielding properties, blackness, and low wavelength dependency of absorbance in the visible light region.

In the present embodiment, the silver-tin alloy part is, for example, the following, not only having the crystal structure of silver-tin intermetallic compound (hereinafter also referred to as “silver-tin intermetallic compound phase”), but also silver In other words, a solid solution of tin in a state where the silver crystal structure is maintained in silver (hereinafter, also referred to as “tin solid solution silver phase”) may be included.
First, as for having a silver tin intermetallic compound phase, the range of X when the silver tin alloy is represented by the chemical formula Ag _1-X Sn _X is ζ phase of 0.118 ≦ X ≦ 0.2285 (space Group P6 ₃ / mmc) and 0.237 ≦ X ≦ 0.25 epsilon phase (space group Pmmn) are known (according to Binary Alloy Phase Diagram, p. 94-97). Comparing the composition and space group of these phases with the X-ray diffraction ICDD card (JCPDS card), the X-ray diffraction data of the ε phase is Ag ₃ Sn (IDCC 71-0530), and the X-ray diffraction data of the ζ phase is It is thought to correspond to Ag ₄ Sn (IDCC 29-1151). Therefore, if the fine particles have a silver-tin alloy part having a structure of orthorhombic ε phase (Ag ₃ Sn) or hexagonal ζ phase (Ag ₄ Sn), chemical stability and blackness And can be satisfied.

Next, as for having a silver crystal structure, a solid solution of tin in a state where the crystal structure of silver is maintained (tin solid solution silver phase), that is, a part of silver atoms in the silver crystal. In this case, when the silver tin alloy is represented by the chemical formula Ag _1-Y Sn _Y , 0 <Y ≦ 0.115, and in the above literature, the (Ag) phase (the following notation is used) The space group represented by: cubic system).

If this range is expressed by Ag _Z Sn (Z is a real number), 7.70 ≦ Z <∞ (infinity).
Note that Y = 0 (Ag ₁ Sn ₀ ) or Z = ∞ (Ag ∞ Sn) corresponds to the Ag single component phase, and thus is excluded from the specified range as the silver-tin alloy part shown here. However, the metal fine particles including fine particles containing silver element and tin element used as the black material in the present embodiment are not only fine particles having a silver-tin alloy portion as described above, but also fine particles having a silver-tin alloy portion. In addition, since mixed fine particles of silver fine particles are also suitable, the black material may include Y = 0.

In addition, according to the said literature, as a silver tin alloy part, what has a crystal structure of tin, ie, the thing which silver solid-solved in the state which maintained the crystal structure of tin in tin (henceforth a "silver solid solution tin phase") Is also not present), and detailed description regarding the silver solid solution tin phase is omitted. However, when a silver solid solution tin phase exists, it shall be included in the silver tin alloy part of this embodiment.

In addition, in the metal fine particles, it is known that the wavelength at which the metal fine particles absorb light is changed by controlling not only the particle diameter but also the particle shape. In this embodiment, particles having various particle sizes and particle shapes are also changed. Can be combined. The range of the particle diameter is as described above. The particle shape can be appropriately selected from one or more of spherical, elliptical, prismatic, rod, plate (triangular plate, hexagonal plate) and the like. The particle shape in the present embodiment is preferably used by combining the following (A) and (B).
(A) At least one kind of fine particles of spherical and elliptical spheres.
(B) At least one kind of fine particles among prismatic shape, rod shape, and plate shape.
Of these, (A) absorbs a lot of light on the low wavelength side of the visible light region, and (B) absorbs a lot of light on the long wavelength side of the visible light region. By combining (A) and (B), the black material of the present embodiment can absorb light in a wide wavelength region, the wavelength dependence of the absorbance in the visible light region is small, and the natural color black Can be obtained.

Here, the particles in (B) may be primary particles that may have a prismatic shape, a rod shape, or a plate shape, and primary particles such as a spherical shape or an oval shape aggregate to form a prismatic shape, a rod shape, or a plate shape. It may be. When the shape of a fine particle changes, the dielectric function changes and the wavelength of the light absorbed by the fine particle changes, but the change in the shape of the aggregated particles, not the primary particles, also affects the dielectric function and changes the wavelength of the absorbed light. It is because it may be done.
Further, the particles (B) may have a complicated shape such as a dendrite (dendritic shape) or a continuous shape by agglomerating (reaggregating) prismatic, rod-like, plate-like particles or aggregated particles.

The method for producing the black material of the present embodiment is not particularly limited as long as it is a method capable of obtaining metal fine particles exhibiting black color by adjusting the composition and particle diameter as described above. Conventional metal fine particle synthesis methods such as a thermal decomposition method, a liquid phase reaction method, a freeze-drying method, and a hydrothermal synthesis method can be applied.
Among these, it is preferable to use a liquid phase reaction method from the viewpoints that it is easy to form fine particles having a silver-tin alloy part and that the shape of the particles can be easily controlled by synthesis conditions. Conventionally, a method for producing an alloy of tin and silver having greatly different oxidation-reduction potentials while controlling the particle diameter and particle shape of the metal fine particles has not been found, but in this embodiment, the reaction temperature, pH, By strictly controlling reaction conditions such as stirring efficiency, it became possible to produce a silver-tin alloy while controlling the particle diameter and particle shape.

As an example of the liquid phase reaction method, for example, a silver compound solution is dropped into a tin colloidal dispersion, silver ions are reduced with tin to alloy tin and silver, and fine particles having a silver-tin alloy part. A method for producing silver fine particles can be exemplified.
In this production method, the content of silver element in the metal fine particles is adjusted by appropriately adjusting the reaction conditions (for example, the ratio of tin and silver ions, the pH of the reaction solution, the reaction temperature, the reaction time, etc.). It can be controlled arbitrarily.

In the liquid phase reaction, since the synthesis is completed by the reaction in the liquid phase, there is no need to recover the black material, and the black material dispersion described later can be easily obtained as it is or through a simple process. Is also possible.
Moreover, when producing a black film using this black material, the water dispersion system may be changed to the organic solvent dispersion system in consideration of dispersibility with the resin component. When changing to an organic solvent dispersion system, a method is adopted in which cake-like aggregates recovered from the liquid phase are dispersed in an organic solvent using a wet mixer such as a ball mill or a bead mill.

The black material of this embodiment thus obtained is required to satisfy the following characteristics.
That is, the absorbance in a dispersion liquid (hereinafter sometimes referred to as “evaluation dispersion liquid”) in which a black material is dispersed so that the solid content is 0.0005% by volume in the dispersion medium is measured at an optical path length of 10 mm. In this case, first, it is necessary that the average absorbance from 380 nm to 800 nm is 0.8 or more. When the average absorbance is less than 0.8, the black film using a black material has insufficient light shielding properties.
The average absorbance is preferably 1.0 or more, more preferably 1.1 or more, and further preferably 1.2 or more.

Further, the ratio d ₄₂₀ / d ₆₈₀ between the absorbance d _{420 at 420} nm and the absorbance d _{680 at 680} nm needs to be 0.6 or more and 2.5 or less. If the ratio of absorbance is within this range, the wavelength dependence of the absorbance in the visible light region of the black film is small, and a black having a natural color tone can be obtained.
The absorbance ratio d ₄₂₀ / d _{680 at 420} nm and 680 nm is preferably from 0.7 to 1.6, more preferably from 0.8 to 1.5, and even more preferably from 0.8 to 1.25.

As the dispersion medium used for the evaluation dispersion liquid, a solvent having the highest absorbance can be appropriately selected. In this embodiment, when the evaluation dispersion liquid is obtained by diluting the black material dispersion liquid of the present embodiment described later, the dispersion medium is actually a dispersion used for the black material dispersion liquid described later. It must be the same as the medium or highly compatible with the dispersion medium used in the black material dispersion.
Specifically, as the dilution solvent (dispersion medium) for the absorbance measurement, when the solvent of the black material dispersion is water, water, ethanol, methanol, 1-propanol, acetone or the like is dispersed in the black material. When the solvent of the liquid is non-aqueous, methyl ethyl ketone, propylene glycol monomethyl ether acetate, toluene, hexane and the like can be exemplified.

For example, when water is used as the dispersion medium, when the specific gravity of water is 1.00 and the specific gravity of the black material is 10.00, the solid content of the black material dispersion is 0.0005% by volume for absorbance measurement. The liquid diluted in this way becomes 0.005% by mass when converted to the mass ratio of the black material.
The solid content in the diluted solution for absorbance measurement is calculated from the mass or volume of the black material that does not contain a dispersing agent or the like attached to the periphery.

When the dispersion for evaluation is obtained by diluting the black material dispersion of the present embodiment described later, the dispersion condition for dispersing the black material depends on the preparation conditions of the black material dispersion of the present embodiment described later. Basically, the metal fine particles containing fine particles containing silver element and tin element are dispersed to such an extent that the average dispersed particle diameter is 5 nm to 100 nm and the 90% cumulative number particle diameter is 1 μm or less. Can be done. If it becomes such a particle diameter and particle size distribution, a dispersion apparatus, a dispersion time, etc. will not be restrict | limited in particular.
In other words, as a dispersion device, a known dispersion processing device such as a bead mill, a ball mill, an ultrasonic dispersion device, or the like may be used, and a dispersion time may be selected in accordance with the characteristics of each device. A dispersant, a dispersion aid, a surface treatment agent, or the like can be used for improvement.
Moreover, as a method of obtaining this evaluation dispersion from the black material dispersion, for example, when a black material dispersion having a metal fine particle content of 25% by mass in the black material dispersion is prepared by the method described later, Dilute the black material dispersion to 0.05% by volume with the dispersion medium used for the material dispersion, mix by hand shaking, further dilute 100 times with the same dispersion medium and mix by hand shaking, solid content Can be obtained as a dilution for absorbance measurement of 0.0005 vol%.

<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 black material content in the dispersion is preferably 1% by mass to 80% by mass, more preferably 5% by mass to 50% by mass, and still more preferably 10% by mass to 40% by mass. Here, the reason why the content of the black material is preferably 1% by mass or more and 80% by mass 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 mass. This is because the effect as a black material may be reduced, and if it exceeds 80% by mass, the concentration of the black material becomes too high and a paste is formed, and the characteristics as a dispersion may be lost. .

(Dispersion medium)
The dispersion medium basically contains at least one of water and an organic solvent.
Examples of the organic solvent include alcohols such as methanol, ethanol, 2-propanol, butanol, and octanol; diethyl ether, ethylene glycol monomethyl ether (methyl cellosolve), ethylene glycol monoethyl ether (ethyl cellosolve), ethylene glycol mono -N-propyl ether, ethylene glycol mono-n-butyl ether (butyl cellosolve), diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol monomethyl ether, triethylene glycol Monoethyl ether, propylene glycol monomethyl ether, propylene Glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-n-butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono- (poly) alkylene glycol monoalkyl ethers such as n-butyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether;
(Poly) alkylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate;
Other ethers such as diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, tetrahydrofuran;
Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, cyclohexanone, 2-heptanone, 3-heptanone;
Lactic acid alkyl esters such as methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, and ethyl lactate;
Ethyl 2-hydroxy-2-methylpropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, 2-hydroxy Methyl-3-methylbutanoate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutylpropionate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, n formate -Pentyl, isopentyl acetate, n-butyl propionate, ethyl butyrate, n-propyl butyrate, isopropyl butyrate, n-butyl butyrate, methyl pyruvate, ethyl pyruvate, n-propyl pyruvate, methyl acetoacetate, ethyl acetoacetate, 2-oxobutanoic acid Le, other esters such as γ- butyrolactone;
Aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene; and amides such as N-methylpyrrolidone, N, N-dimethylformamide, and N, N-dimethylacetamide are preferably used. Among these solvents, 1 Species or two or more can be used.

Among the above, the water content in the dispersion when a water-insoluble organic solvent is used is preferably 5% by mass or less, more preferably 3% by mass or less, and still more preferably 2% by mass or less.
When the water content of the dispersion exceeds 5% by mass, the dispersion is caused when the black material dispersion in which the black material is dispersed is mixed with a non-aqueous resin component or resin-forming component for the purpose of forming a black resin composition such as paint. The liquid and the resin component or the resin-forming component are easily separated, and it may be difficult to obtain a stable mixture (paint or the like). That is, by setting the water content of the dispersion to 5% by mass or less, it is possible to appropriately select a non-aqueous resin component or a resin-forming component suitable for desired characteristics from among many types. There is no restriction in the resin composition (paint) or coating film, and the degree of freedom in designing can be expanded.

(Other ingredients)
In the dispersion liquid of the present embodiment, it is preferable to use a dispersant and / or a dispersion aid or a surface treatment agent in combination in order to improve the dispersibility of the black material and the dispersion stability. Among these, it is particularly preferable to use a polymer dispersant as the dispersant because the dispersion stability over time is excellent. Here, the dispersant is a polymer having a completely different structure from the black material for ensuring the dispersion stability of the black material, and the dispersion aid is a pigment derivative for enhancing the dispersibility of the black material. Say.

  In general, the classification of polymer dispersants includes, for example, urethane dispersants, polyethyleneimine dispersants, polyoxyethylene alkyl ether dispersants, polyoxyethylene glycol diester dispersants, sorbitan aliphatic ester dispersants. , Aliphatic modified polyester dispersants, polycarboxylates, polyalkyl sulfates, polyvinyl pyrrolidone (PVP), polyvinyl alcohol (PVA), polyacrylamide and the like. Of these, urethane dispersants are preferred in view of compatibility with ionizing radiation curable resins, thermosetting resins and thermoplastic resins used as resins, and compatibility with organic solvents.

In addition, when the polymer dispersant is classified by the structure depending on the production method, there are a random copolymer, a comb copolymer, an ABA block copolymer, a BAB block copolymer, a hydrophilic group-containing polymer at one end, a hydrophilic group-containing polymer at one end, etc. . Among these, a random copolymer and a comb polymer are preferable in consideration of compatibility with an ionizing radiation curable resin, a thermosetting resin, and a thermoplastic resin used as a resin, and compatibility with an organic solvent.
Specific examples of the dispersant satisfying these conditions include EFKA (manufactured by EFKA Chemicals Beebuy (EFKA)), Disperbyk (manufactured by BYK Chemie), and SOLPERSE (manufactured by Geneca). Moreover, these dispersing agents can be used 1 type or in mixture of 2 or more types.

  Moreover, it is preferable that the addition amount with respect to the black material of the said dispersing agent is 5 to 50 mass parts when black material is 100 parts. When the amount of the dispersant added is less than 5 parts by mass, the amount of the dispersant necessary for dispersing the black fine particles is insufficient, so that the dispersibility of the dispersion cannot be maintained. The average particle size inside may not be satisfied. Further, when the amount of the added dispersant exceeds 50 parts by mass, the amount of the dispersant becomes excessive with respect to the black material, and the dispersibility of the dispersion cannot be maintained due to the interaction between the dispersants. The dispersed particle size, 90% cumulative volume particle size may not be satisfied.

In the black material dispersion, the average dispersed particle diameter of the metal fine particles (black material) dispersed in the solvent is preferably 5 nm or more and 100 nm or less. Since the average primary particle diameter of the metal fine particles in this embodiment is 3 nm or more, it is difficult to obtain a dispersion having an average dispersed particle diameter of less than 5 nm. When the average dispersed particle diameter exceeds 100 nm, the dispersion of the fine particles in the black material dispersion is not sufficient, and the light-shielding property may be deteriorated or the appearance may become whitish due to the scattering of the fine particles and the blackness may be lowered. .
The average dispersed particle size is more preferably 5 nm or more and 80 nm or less, and further preferably 5 nm or more and 50 nm or less.

The 90% cumulative volume particle size of the metal fine particles (black material) dispersed in the solvent of the black material dispersion is preferably 1 μm or less. If the 90% cumulative volume particle diameter exceeds 1 μm, the dispersion of the fine particles in the black material dispersion is not sufficient and coarse particles are present, so that the light-shielding property is deteriorated or the appearance is caused by the scattering of the fine particles. It may become whitish and the blackness may decrease.
The 90% cumulative number particle size is more preferably 0.6 μm or less.

Regarding the method of measuring the average dispersed particle size and 90% cumulative volume particle size in the above dispersion, the particle size distribution of this dispersion is measured using a particle size distribution measuring apparatus by a dynamic light scattering method, and the fine particles in the dispersion are measured. When the cumulative curve was determined with the total volume of 100% as the total volume, the particle size at the point where the cumulative curve was 50% was the average dispersed particle size, and the particle size at the point where the cumulative curve was 90% was the 90% cumulative volume particle size.
Further, the average dispersed particle size and 90% cumulative volume particle size in the black paint described later were also determined by the same measurement method.

The black material dispersion of this embodiment can be prepared by mixing and dispersing a black material and components such as a dispersant and a dispersion aid as required in addition to a dispersion medium. The mixed dispersion method may be selected from known dispersion treatment methods such as an ultrasonic disperser, a paint shaker, a ball mill, a bead mill, an Eiger mill, etc., but a bead mill is preferable from the viewpoint of dispersibility. . A plurality of dispersion methods may be used in combination.
For example, when the above bead mill is used, the ratio of (mass of beads) / (mass of dispersion) in the dispersion chamber in a batch type bead mill is 0.5 to 15 and the rotation speed is 1000 rpm to 4000 rpm. It is preferable to disperse for about 1 hour to 10 hours.
As preferable dispersion conditions, for example, a ratio of (mass of beads) / (mass of dispersion) is set to 3.5, and dispersion is performed at 2500 rpm for about 2 hours.

<Black resin composition>
The black resin composition of the present embodiment includes at least the black material of the present embodiment and a resin forming component or a resin component, and includes a paint and the like. The resin component is the same as the resin component in the black film described later, and the resin forming component is a component for forming the resin component in the black film described later.
Here, the main components for constituting the black resin composition are the following five types [A] to [E]. Note that [B] and [E] are different.
[A] Black material [B] Black material dispersion medium [C] Resin forming component [D] Resin component [E] Resin forming component or solvent of resin component

The black resin composition is mainly composed of a combination of these five components, and the combinations are as follows (1) to (7). In order to disperse the metal fine particles constituting the black material in the black resin composition, the black material is preferably treated with a dispersant. However, since the dispersant is an additional component, the description here Is omitted. In addition, descriptions of components other than [A] to [E] that can be added as necessary, that is, dispersion aids and surface treatment agents are omitted here.
(1): [A] + [C]
It is a two-component system that is a minimum combination, and can be regarded as a dispersion of a black material in a liquid resin-forming component. In this case, [C] needs to be liquid.
(2): [A] + [B] + [C]
It is a three-component system and can be regarded as a mixture of the “black material dispersion” and a resin-forming component. In general, [C] needs to be liquid, but when [C] is soluble in [B], [C] may be solid.
(3): [A] + [C] + [E]
It can be regarded as a three-component system in which a black material is dispersed in a resin-forming component dissolved in a solvent. Since [C] is dissolved in [E], it may be liquid or solid.
(4): [A] + [D] + [E]
It is a three-component system and can be considered as a black material dispersed in a resin component dissolved in a solvent. Since [D] is a solid, [E] is indispensable as long as [D] is present.
(5): [A] + [B] + [D]
This is a combination that is possible only when [D] is soluble in [B], and can be considered as a resin component dissolved in the “black material dispersion”. Only in this case, [E] is exceptionally unnecessary.
(6): [A] + [B] + [C] + [E]
(7): [A] + [B] + [D] + [E]
It is a four-component system, and can be regarded as a mixture of a resin forming component or a solution in which a resin component is dissolved in the “black material dispersion”. In this case, [B] and [E] must be highly compatible. When the compatibility between the two is low, even if the “black material dispersion liquid” and the “resin-forming component or solution in which the resin component is dissolved” exist stably, the phase separation and the particle component will occur when both are mixed. This is not preferable because aggregation of the liquid occurs. When [B] and [E] are the same, (6) is included in (2) or (3), and (7) is included in (4) or (5).

  Of the above black material [A], black material dispersion medium [B], resin forming component [C], resin component [D], resin forming component or resin component solvent [E], black material, black material dispersion Since the medium has been described above, the resin component, the resin forming component, the resin forming component, or the solvent of the resin component will be described here.

(Resin forming component, resin component)
The resin forming component is a component for forming a resin component in a black film, which will be described later, and usually includes a resin component monomer, oligomer, or prepolymer. That is, as the resin component, various kinds of ionizing radiation curable resins, thermosetting resins, thermoplastic resins, and the like can be used, and therefore at least any of monomers, oligomers, and prepolymers of these resins is included.

  When an ionizing radiation curable resin is selected as the resin component, the ionizing radiation polymerizable monomer (monomer) that is the resin forming component is a polyfunctional compound that is a polymerizable monomer having a radical polymerizable functional group in the molecule ( (Meth) acrylates are preferred, specifically ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) ) Acrylate, caprolactone-modified dipentaerythritol hexa (meth) acrylate, and the like. Examples of the monomer having a cationic polymerizable functional group include alicyclic epoxides such as 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexenecarboxylate, and glycidyl ethers such as bisphenol A diglycidyl ether. , Vinyl ethers such as 4-hydroxybutyl vinyl ether, and oxetanes such as 3-ethyl-3-hydroxymethyloxetane. These ionizing radiation polymerizable monomers may be used singly or in combination of two or more, or may be used in combination with an ionizing radiation polymerizable prepolymer described later.

  Examples of the ionizing radiation polymerizable prepolymer (including oligomers) include polyester (meth) acrylate, epoxy (meth) acrylate, urethane (meth) acrylate, polyol (meth) acrylate, and silicone (meth). Cationic polymerization in molecules such as polymerizable oligomers having radical polymerizable functional groups in molecules such as acrylates and unsaturated polyesters, or epoxy resins such as novolac epoxy resin prepolymers and aromatic vinyl ether resin prepolymers And polymerizable oligomers having a functional functional group. These ionizing radiation polymerizable prepolymers may be used singly or in combination of two or more. Here, “(meth) acrylate” means “acrylate or methacrylate”.

Further, the resin component is a thermosetting resin such as phenol resin, phenol-formalin resin, urea resin, urea-formalin resin, melamine resin, polyester-melamine resin, melamine-formalin resin, alkyd resin, epoxy resin, epoxy-melamine. When resin, unsaturated polyester resin, polyimide resin, acrylic resin, polysiloxane resin, polyurethane resin, general-purpose two-component curable acrylic resin (acrylic polyol cured product), etc. are selected, the resin-forming component is thermosetting Examples thereof include a raw material compound for forming a resin, a monomer, an oligomer, and a prepolymer of a polymerizable resin.
Further, when a polyester resin, alkyd resin, polyurethane, polyvinyl pyrrolidone, polyvinyl alcohol or the like, which is a thermoplastic resin, is selected as the resin component, the resin-forming component is a raw material compound for forming these thermoplastic resins. And monomers, oligomers, and prepolymers of polymerizable resins.

  Furthermore, a reactant, a reaction initiator, a polymerization agent, a polymerization initiator, and the like, which are added to form a resin from these raw material compounds, polymerizable resin monomers, oligomers and prepolymers, are included in the resin forming component. Also good.

Here, the content of the resin forming component in the total solid content in the black resin composition is preferably 5% by mass or more and 70% by mass or less, and more preferably 10% by mass or more and 50% by mass or less.
If there are too many resin-forming components than this range, when a black film is formed, there may be insufficient black material existing in the unit volume of the resin component, so that sufficient light-shielding properties may not be ensured. If the amount is too small, a preferable shape as a black film may not be formed, for example, a uniform film body may not be formed or a necessary film thickness may not be obtained.

(Resin-forming component or resin component solvent)
The resin-forming component or the solvent for the resin component (hereinafter sometimes referred to as “resin solvent”) is a liquid in which the resin-forming component or the resin component is highly soluble. It is selected from one type or two or more types.
As the resin solvent, in addition to the high solubility of the resin-forming component or resin component, the dispersibility of the black material is high, the compatibility with the black material dispersion is high, and when mixed with the black material dispersion In addition, it is necessary to satisfy the condition that the dispersibility of the black material and the solubility of the resin component and the resin forming component do not decrease. When these conditions are not satisfied, even if the “black material dispersion liquid” and the “resin forming component or the solution in which the resin component is dissolved” exist stably, both are mixed to form a black paint. At this time, phase separation, aggregation and sedimentation of the black material, precipitation of the resin-forming component or resin component, etc. occur, which is not preferable because a good black paint cannot be obtained. Here, it is preferable that the same or similar solvent can be selected as the resin solvent and the black material dispersion because such problems can be avoided.
In addition, as said organic solvent, the organic solvent used for the above-mentioned black material dispersion liquid can be used similarly.

Also in the black resin composition of the present embodiment, a dispersant and / or a dispersion aid and a surface treatment agent are added to improve the dispersibility and dispersion stability of the black material as in the black material dispersion. It is preferable to use together. Among these, it is particularly preferable to use a polymer dispersant as the dispersant because the dispersion stability over time is excellent. Since the dispersant and the dispersion aid are the same as those described in the black material dispersion, the details are omitted.
In addition, when a dispersion containing a dispersant and / or a dispersion aid or a surface treatment agent is selected as the black material dispersion of this embodiment, and this black material dispersion is used as a raw material for a black paint, the dispersion Dispersants, dispersion aids and surface treatment agents already contained in the liquid may be used as they are. The reason for this is that the dispersant, dispersion aid and surface treatment agent are substances that modify the surface of the black material so that the surface of the black material has an affinity for the dispersion medium and solvent. This is because it is not necessary to treat with another type of dispersant or dispersion aid if the characteristics are not different from those of the medium or solvent.

For the black resin composition described above, at least the black material and the resin-forming component and / or resin component are selected, and if necessary, a black material dispersion medium, a resin-forming component or a resin component solvent is added, and photopolymerization is further performed. It can be prepared by adding an initiator, a dispersant and other components and mixing and dispersing. Among these, the black material, the black material dispersion medium, the resin forming component, the resin component, the resin forming component, or the combination of the resin component solvents are as described above.
In this case, a black resin composition may be prepared by preparing a black material dispersion in advance and adding and dissolving a resin-forming component, a photopolymerization initiator, and the like. Moreover, it can also prepare by mixing the black material dispersion liquid prepared previously, and the solution which melt | dissolved components, such as a resin formation component and a photoinitiator.
The mixed dispersion method may be selected from known dispersion treatment methods such as an ultrasonic disperser, a paint shaker, a ball mill, a bead mill, an Eiger mill, etc., as a mixed liquid in which black materials and resin forming components are mixed. To bead mills are preferred. A plurality of dispersion methods may be used in combination. When a black material dispersion prepared in advance is used, the black material dispersion and the solution in which the resin-forming components are dissolved are sufficiently mixed and stirred without performing the above-described dispersion treatment method when the black resin composition is produced. There are cases where it may be sufficient.

<Black film>
The black film of the present embodiment comprises at least the black material of the present embodiment and a resin component.
As the resin component in the present embodiment, a resin component that cures in a state where the metal fine particles exhibiting black, which is a black material, are uniformly dispersed, and that is suitable for the characteristics required for the formed black film should be selected. That's fine. As this resin component, various kinds of ionizing radiation curable resins, thermosetting resins, thermoplastic resins, etc. described in the above black resin composition can be used.

  The black film of the present embodiment can be obtained by forming a film body by various known coating methods using a black paint that is one of the black resin compositions described above. For example, the black film is formed by applying the above black paint on one main surface of a substrate, roll coating method, spin coating method, dip coating method, spray coating method, bar coating method, slit coating method, slit & spin coating method. It can be easily obtained by forming the coating film by various coating methods such as, removing the solvent from the coating film by volatilization, etc., and performing a curing treatment if necessary.

This curing treatment is usually a process in which a resin-forming component in the coating film is reacted by polymerization or the like to form a resin component. When an ionizing radiation curable resin is used as the resin-forming component, ultraviolet rays, electron beams, X-rays are used. In the case of using a heat-reactive resin such as a thermoplastic resin material to which a thermal polymerization catalyst is added as a resin-forming component. Includes a heat treatment.
Further, in the case where the component in the black paint is a resin component dissolved in a solvent, the curing process is a step of removing the solvent from the resin component in the coating film, and the heat treatment is performed under atmospheric pressure or reduced pressure. Can be mentioned. In this case, since the resin component cured by solvent removal may be swollen and dissolved again by exposure to the same solvent, it is preferable to remove the solvent completely by tightening the heat treatment conditions. . Here, when an ionizing radiation curable resin is used as the resin component, the resin component may be completely cured by applying radiation such as ultraviolet rays, electron beams, and X-rays after the solvent is removed, and further by performing a heat treatment. When a heat-reactive resin is used, the curing reaction may be completed by heat treatment after removing the solvent.

  As a black film using the black paint, in the case of a film body patterned into a specific shape, for example, a black matrix, a black paint containing an alkali-soluble resin, a photopolymerization initiator, an ethylenically unsaturated compound is used, It is desirable to impart light (ultraviolet) photosensitivity to the coating film formed by applying the black paint. If the coating film has photosensitivity, the coating film is exposed to a specific pattern using a photomask or the like, then developed and cured to form a black film having a specific shape such as a black matrix. Can be easily obtained.

The alkali-soluble resin is not particularly limited as long as it contains a carboxyl group or a hydroxyl group. For example, an epoxy acrylate resin, a novolac resin, a polyvinylphenol resin, an acrylic resin, a carboxyl group-containing epoxy resin, a carboxyl group-containing resin Urethane resins and the like can be mentioned, but among these, epoxy acrylate resins, novolac resins, and acrylic resins are preferable, and resins having an aromatic ring structure are particularly preferable in terms of providing high volume resistivity and low dielectric constant. .
In this case, the ratio of the alkali-soluble resin to the total solid content in the black paint is preferably 5% by mass or more and 70% by mass or less, more preferably 10% by mass or more and 50% by mass or less. If the proportion of the alkali-soluble resin is too much above this range, sufficient sensitivity may not be ensured when forming the black matrix pattern, and the necessary light-shielding properties may not be ensured. It may not be formed.

The said photoinitiator is a compound which can generate the radical which superposes | polymerizes an ethylenically unsaturated group with an ultraviolet-ray or a heat | fever.
As the photopolymerization initiator, oxime derivatives (oxime compounds) are particularly effective in terms of sensitivity, and when the light-shielding property is increased or an alkali-soluble resin containing a phenolic hydroxyl group is used, the sensitivity point is increased. In particular, such oxime derivatives (oxime compounds) having excellent sensitivity are useful. In this embodiment, the said photoinitiator may be used individually by 1 type, and may use 2 or more types together.
When the resin black matrix is formed, the ratio of the photopolymerization initiator in the dispersion is preferably 0.4% by mass or more and 15% by mass or less, more preferably 0.5% by mass with respect to the total solid content. It is 10 mass% or less. If the proportion of the photopolymerization initiator is too much above this range, the development speed may be too slow, whereas if it is too small, sufficient sensitivity may not be obtained, and a preferable resin black matrix shape may not be formed.

  The ethylenically unsaturated compound means a compound having at least one ethylenically unsaturated bond in the molecule, but there are differences in polymerizability, crosslinkability, and associated developer solubility in exposed and non-exposed areas. It is preferable that it is a compound which has two or more ethylenically unsaturated bonds in a molecule | numerator, and the (meth) acrylate compound from which the unsaturated bond originates in a (meth) acryloyloxy group from the point of being able to expand the ratio. Further preferred. Furthermore, the use of a compound having three or more ethylenically unsaturated bonds in the molecule is preferable for the electrical properties such as volume resistivity and relative dielectric constant of the formed film.

Examples of the compound having one or more ethylenically unsaturated bonds in the molecule include unsaturated carboxylic acids such as (meth) acrylic acid, crotonic acid, isocrotonic acid, maleic acid, itaconic acid, citraconic acid, and alkyls thereof. Examples include ester, (meth) acrylonitrile, (meth) acrylamide, styrene and the like.
Examples of the compound having two or more ethylenically unsaturated bonds in the molecule include esters of unsaturated carboxylic acids and polyhydroxy compounds, (meth) acryloyloxy group-containing phosphates, and hydroxy (meth) acrylates. Examples include urethane (meth) acrylates of a compound and a polyisocyanate compound, and epoxy (meth) acrylates of a (meth) acrylic acid or hydroxy (meth) acrylate compound and a polyepoxy compound.

The black film of this embodiment preferably has an optical density (OD value) of 1 or more per 1 μm thickness. If the optical density per 1 μm is less than 1, sufficient light shielding properties cannot be obtained if the thickness of the black film is about several μm, and the film thickness must be increased to obtain sufficient light shielding properties. For this reason, particularly when used as a black matrix or the like, the disconnection of the wiring or the display unevenness is likely to occur due to the increase in the film thickness. Therefore, it is preferable to set the optical density per 1 μm to 1 or more as a range in which sufficient light shielding properties can be obtained without increasing the film thickness more than necessary.
The optical density per 1 μm is more preferably 1.2 or more, and further preferably 1.5 or more.
Here, since the black material of the present embodiment has a high blackness and is excellent in dispersibility in the resin, the black film of the present embodiment can be obtained by increasing the amount of the black material. The optical density per 1 μm can be easily set to 2 or more, and can also be set to 3 or more while avoiding adverse effects due to an increase in film thickness, for example, a decrease in film strength and a decrease in blackness due to aggregation of black materials. Therefore, a high light shielding property can be obtained without increasing the thickness of the black film. The higher the optical density per 1 μm, the better, but the upper limit is about 10 due to measurement limitations.
Furthermore, the lower the reflectance of the black film, the higher the blackness of the black film is preferable. When the reflectance is high, the black film looks white and the quality of the film deteriorates. The average reflectance of visible light obtained by averaging the reflectances from 380 nm to 800 nm is preferably 20% or less, more preferably 15% or less, and even more preferably 10% or less.

Here, the optical density per 1 μm thickness can be determined as follows.
The sample is formed into a film on a transparent substrate for measurement of transmission. While measuring the optical density of this film-like sample with a transmission densitometer, measuring the film thickness using a stylus type surface shape measuring instrument, etc., and dividing the optical density value of the obtained sample by the film thickness, The optical density per 1 μm thickness can be determined. In addition, it is preferable that the optical density of the film-like sample is about 4.0 or less because a decrease in measurement accuracy can be prevented.

The volume resistivity of the black film is preferably 10 ¹¹ Ω · cm or more. This is because, in a COA type or BOA type liquid crystal display element or a self-luminous display device, the element driving wiring contacts the black matrix or the light shielding wall, or the element driving wiring directly on the black matrix or the light shielding wall. Since the structure that provides the mainstream is becoming the mainstream, if the volume resistivity of the black matrix or the light shielding wall formed using the black film is less than 10 ¹¹ Ω · cm, it is easy to cause a short circuit between the wirings. This is to cause malfunction of the TFT element. Also, in the IPS drive type liquid crystal, if the black matrix formed using the black film has conductivity, an unnecessary electric field is generated in a direction different from the electric field for driving the liquid crystal, and the image is disturbed. It is.
The volume resistivity of the black film is more preferably 10 ¹² Ω · cm or more, and further preferably 10 ¹³ Ω · cm or more. The higher the volume resistivity of the black film, the better. The upper limit is not particularly limited, but it is usually 10 ¹⁸ Ω · cm or less.
The volume resistivity can be measured by using a commercially available volume resistivity meter, for example, by a four-probe method.
Since the black material of the present embodiment has high blackness, the content in the black film can be reduced compared to the conventional black material, and the dispersibility in the resin is also excellent. A conductive path formed by agglomerating particles so as to be continuous is not generated. Therefore, even if the optical density per 1 μm is increased as described above, the volume resistivity can be maintained at a high value.

<Base material with black film>
The base material with a black film of the present embodiment is configured by providing the black film of the present embodiment described above on a base material. Specifically, for example, a layer formed as described above using a black paint that is one of the black resin compositions described above is patterned on a light-transmitting substrate as necessary. Is done.

  Although it does not specifically limit as said base material, A glass base material, a plastic base material (organic polymer base material), etc. can be mentioned. Moreover, as the shape, a flat plate, a film form, a sheet form, etc. are mentioned. Moreover, as said plastic base material, a plastic sheet, a plastic film, etc. are suitable.

The material of the glass substrate is not particularly limited, and can be appropriately selected from, for example, soda glass, alkali glass, non-alkali glass, and the like.
The material of the plastic substrate is not particularly limited. For example, cellulose acetate, polystyrene (PS), polyethylene terephthalate (PET), polyether, polyimide, epoxy resin, phenoxy resin, polycarbonate (PC), It can be appropriately selected from polyvinylidene fluoride, triacetylcellulose, polyethersulfone (PES), polyacrylate, and the like based on the application and use conditions.

Further, the method of patterning the layer formed using the black paint is not particularly limited, and as described above, an alkali-soluble resin, a photopolymerization initiator, an ethylenically unsaturated compound is included in the black paint, Applying this black paint to form a coating film with light (ultraviolet) photosensitivity, exposing the coating film to a pattern and developing it to form a black film, Accordingly, other processes such as post exposure and post bake can be provided.
For patterning processes such as exposure and development, known methods can be used. For example, when applied as a black matrix for an image display device, the methods described in paragraph numbers 0096 to 0106 of JP-A-2006-251095. Alternatively, the method for forming a light-shielded image described in paragraph numbers 0116 to 0126 of JP-A-2006-251237 can also be suitably used in this embodiment.

There is also a method for producing a layer in which a pattern is directly formed on a substrate using the black paint and using an inkjet method. In this case, it is not necessary to give photosensitivity to the black paint film, but the black paint is excellent in dischargeability (discharge volume and stability in the discharge direction) from a minute ink jet nozzle and is not discharged. The paint adhering to the material must be in a highly viscous state so that it does not flow out or deform. For this reason, methods such as adjusting the viscosity of the black paint or adding an auxiliary agent for giving thixotropy are used.
Although a known method can be used for this step, for example, when it is applied as a black matrix for an image display device, the method described in paragraph numbers 0029 to 0031 of JP-A-2008-116895 can be used.

The black film of the present embodiment exhibits high light blocking properties (not transmitting light) and blackness (low light reflectivity) in a wide range of visible light region. Therefore, the base material with a black film of the present embodiment can be suitably used as a member for an image display device utilizing light shielding properties and blackness. These members include black matrixes in liquid crystal display elements and self-luminous display devices, color filters and black stripes using the same, light-shielding walls that separate pixels of each color in liquid crystal display devices and self-luminous display devices, liquid crystals Examples include a spacer between substrates filled with liquid crystal in a display device.
That is, the black film-coated substrate of the present embodiment can be suitably used for self-luminous display devices such as plasma display devices and EL display devices, CRT display devices, liquid crystal display devices, and the like. When used in an EL display device, the effect of the black film of this embodiment is remarkably exhibited. Here, examples of the liquid crystal display device include STN, TN, VA, IPS, OCS, and R-OCB.

The black film of this embodiment has a high light-shielding property and blackness, and a high light-shielding property can be obtained even if the black material has a smaller volume fraction than a black film using a black material such as existing carbon black. As a result, for example, in application to a black matrix and a color filter using the same, the thickness of the black matrix can be reduced due to high blackness, and the flatness of the resulting color filter can be increased. Therefore, in the liquid crystal display device provided with this color filter, the cell gap unevenness does not occur between the color filter and the substrate, and the occurrence of display defects such as color unevenness is improved.
That is, the film thickness of the black film is preferably 0.2 μm or more and 5.0 μm or less, and particularly preferably 0.2 μm or more and 4.0 μm or less when the substrate with black film of the present embodiment is a black matrix substrate. Thus, since the black film of this embodiment is used as the black film in the black matrix substrate, even a thin film has a high optical density.

In addition, the black film of this embodiment can obtain a high light-shielding property even if the volume fraction of the black material is small, and is excellent in the dispersibility of the black material. It is difficult to occur, the volume resistivity of the film can be increased, and both high light shielding properties and high volume resistivity of the film can be achieved.
As a result, even when the black matrix and the pixel driving wiring are in contact with each other as in the case of a COA type or BOA type liquid crystal display element or a self-luminous display device, there is a risk of driving failure of the element due to a short circuit of the wiring. There is no.

Further, even when applied to a light shielding wall or a spacer, since the volume resistivity is high, there is no possibility that the wiring between the pixels is short-circuited, and therefore, the driving failure of the element is not caused. Furthermore, since the blackness is high, the thickness of the light shielding wall can be reduced, and the contrast can be improved by expanding the light emitting region in each pixel, or the density of the light emitting elements can be increased due to the decrease in the pixel spacing. .
Furthermore, it can be applied to a contrast enhancement film or the like by utilizing high light absorption.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited at all by these Examples.
<Measurement and evaluation methods>
Below, each measurement or evaluation method, such as the characteristic of a material and a sheet | seat employ | adopted in the Example or the comparative example, is shown.
-Black material Particles were separated from an aqueous dispersion of black fine particles, which will be described later, and dried to obtain a powder sample, which was evaluated as follows.
(Identification of contained fine particle species)
The powder phase is identified from the crystal phase and composition ratio (content ratio) by identifying the crystal phase with an X-ray diffractometer (XRD) and qualitatively and quantitatively analyzing the green compact with an electron beam microanalyzer (EPMA). The metal particle species to be confirmed was confirmed.
[Identification of crystal phase by XRD measurement]
The powder sample was packed in a glass sample holder and measured using CuKα rays with an X-ray diffractometer (manufactured by PANalytical, X′Pert PRO). In the obtained XRD profile, peaks at diffraction angles 2θ = 38 ° and 44 ° are silver, and peaks at 2θ = 34.7 ° and 39.7 ° are silver-tin intermetallic compounds (Ag ₃ Sn and / or The crystal phases of the metal particle species contained were confirmed by identifying the peaks around 2θ = 30.7 ° and 32 ° as tin crystal phase peaks (Ag ₄ Sn).
[Qualitative and quantitative analysis by EPMA measurement]
The presence of tin and silver in the powder by analyzing the green compact powder using an electron beam microanalyzer (EPMA, JEOL Ltd., JXA8800) and qualitative and quantitative analysis using a wavelength dispersive X-ray spectrometer. And the content ratio (mass ratio) was measured.
[Identification of fine particle species from XRD measurement and EPMA measurement]
By confirming that the crystal phase identified by the XRD measurement has a sufficient amount of elements constituting the crystal phase by EPMA measurement, the fine particle species was identified.
That is, for a sample in which the crystal phase of the silver-tin intermetallic compound was confirmed by XRD measurement, the presence of silver and tin was confirmed by EPMA measurement, whereby the fine particle species was identified as containing a silver-tin intermetallic compound, and XRD About the sample in which the crystalline phase of tin was confirmed by the measurement, the presence of tin was confirmed by the EPMA measurement, whereby the fine particle species was identified as containing tin. In addition, regarding the sample in which the silver crystal phase was confirmed by XRD measurement, the presence of silver was identified by confirming the presence of silver by EPMA measurement. However, only the silver crystal phase was confirmed by XRD measurement. In spite of this, for samples in which the presence of silver and tin was confirmed by EPMA measurement, the amount of tin was also taken into account, and in addition to silver, tin remained solid while maintaining the crystal structure of silver. It was identified that a dissolved tin solid solution silver, that is, a silver tin alloy part was also included.
(Average primary particle diameter and particle shape of metal fine particles)
A sample obtained by diluting a black material dispersion prepared from a black material powder was observed with a transmission electron microscope (TEM: H-800, manufactured by Hitachi High-Tech Fielding). Arbitrary 50 to 100 particles were selected from the observation field, each particle image was approximated by a circle, and the diameter of the circle was defined as the particle diameter of the particle (particle diameter corresponding to the circle diameter). The cumulative number distribution of particle diameters was obtained from the obtained results, and the particle diameter (median diameter) corresponding to the cumulative value of 50% was taken as the average primary particle diameter of the black material in the film.
At the same time, the particle shapes of the observation particles were classified into spherical, elliptical, prismatic, rod, and plate shapes, and the shapes until the total number reached 80% by number or more in the order of increasing number were described.

Black material dispersion (average dispersed particle size, 90% cumulative volume particle size)
For the prepared black material dispersion, the particle size distribution of the dispersion is measured using a particle size distribution measuring apparatus (Nikkiso Co., Ltd., Microtrac 9340-UPA) to which the dynamic light scattering method is applied. From the obtained distribution result The volume average particle size (MV value) was determined by arithmetic average, and the value was defined as the average dispersed particle size. Further, a cumulative particle size distribution was calculated from the measured particle size distribution, and a 90% cumulative volume particle diameter corresponding to a volume cumulative value of 90% was determined.
(Absorbance of the dispersion)
The black material dispersion is diluted with the dispersion medium so that the solid content of the black material is 0.0005% by volume, and the absorbance of the diluted liquid is measured with a self-recording spectrophotometer (Shimadzu Corporation, UV-3150). did.
The absorbance from 380 nm to 800 nm measured every 1 nm was averaged to obtain the average absorbance in the visible light region. Further, the absorbance at 380 nm, 420 nm, 680 nm, and 800 nm was shown, and the ratio (d ₄₂₀ / d ₆₈₀ ) of the absorbance d _{420 at 420} nm and the absorbance d ₆₈₀ at ₆₈₀ nm was calculated.

・ Black film (optical density (film shading))
About the glass substrate in which the black film was formed, the optical density (OD value: Optical Density) in the visible light region was measured using a transmittance densitometer (manufactured by TECHKON, RT-120), and the glass substrate alone measured in the same manner ( By using the measured value of “without film” as a reference value, the OD value of the black film itself was obtained.
(Reflectance)
The reflectance of the glass substrate with the black film was measured with a spectrophotometer (manufactured by Jusco Engineering, V-570), and the average reflectance of 380 nm to 800 nm was defined as the average reflectance of visible light.
(Color)
Since black materials or black material dispersion liquids have high blackness and it is difficult to evaluate the color, a liquid obtained by diluting the black material dispersion liquid to a solid content of 0.0005% by volume for the absorbance measurement is visually observed. Taste was evaluated.
(Volume resistivity of black film)
A glass substrate having an ITO film formed on the surface by sputtering is selected as the film forming substrate, and an insulation resistance meter (Ultra High Resistance / Microammeter R8340A, manufactured by ADC) is used for the black film formed on the substrate. Was used to measure the volume resistivity. The volume resistivity measurement was performed at DC 5V.

<Example 1>
(Preparation of black material dispersion)
The silver nitrate 56g was melt | dissolved in the pure water, and 1500 g of silver nitrate aqueous solution (A liquid) was prepared. Further, 157 g of trisodium citrate dihydrate and 180 g of polyvinylpyrrolidone diluted to 1% by mass were dissolved in pure water to prepare 2500 g of an aqueous solution of trisodium citrate (solution B). Next, after liquid A was dropped into and mixed with liquid B, 500 g of an aqueous solution in which 0.2 g of sodium borohydride was dissolved in pure water was dropped and mixed, and further 18 g of ascorbic acid was dissolved in pure water. 500 g of the aqueous solution was added dropwise and mixed to obtain solution C.
Subsequently, the said C liquid was dripped and mixed in 4000 g of tin fine particle dispersion liquid which mixed tin colloid A (average particle diameter: 20 nm, solid content: 10 mass%, Sumitomo Osaka Cement Co., Ltd.) and pure water. Further, an aqueous solution in which 180 g of tartaric acid was dissolved in 2000 g of pure water was dropped into a mixed liquid of the tin fine particle dispersion and the C liquid and stirred to dissolve excess tin colloid. Thereafter, washing was performed by centrifugation to prepare an aqueous dispersion of black fine particles (liquid D, solid content: 25% by mass).

Next, after mixing 100 g of the above solution D, 3.75 g of a comb-shaped urethane polymer dispersant and 34 g of methyl ethyl ketone, moisture and methyl ethyl ketone were evaporated from the mixture using an evaporator to obtain a dry powder (E powder).
Next, 29 g of the above E powder and 71 g of propylene glycol monomethyl ether acetate (PGMEA) were mixed and dispersed using a bead mill to obtain a black material dispersion (liquid F, solid content: 25% by mass).

(Production of black film)
A black material dispersion (liquid F), a resist (dispersion medium: PGMEA) containing polyfunctional acrylate as a resin-forming component, and PGMEA as a solvent so that the solid content volume ratio (black fine particles: resist) is 10:90. And dispersed by sonication to obtain a black paint. In addition, the said solid content volume ratio is a preparation ratio.
Next, the prepared black paint was applied onto a 0.7 mm thick glass substrate using a spin coater, pre-baked on a hot plate at 120 ° C. for 2 minutes, and further post-baked at 230 ° C. for 30 minutes, A glass substrate with a black film was obtained. The film thickness of the black film was 1 μm.

(Evaluation)
With respect to the black material, black material dispersion, and black film obtained above, the average primary particle diameter of fine particles, the absorbance of the black material dispersion, and the like were measured according to the above conditions. FIG. 1 shows a spectral absorption spectrum of a dispersion liquid in which a black material is dispersed. As shown in this figure, the absorption characteristics showed almost the same absorbance from 400 nm to 800 nm, and the color was also natural black. Furthermore, the volume resistivity of the black film was 10 ¹⁵ Ω · cm.
The results are summarized in Table 1.

<Example 2>
In the preparation of the black material dispersion liquid of Example 1, the black material dispersion liquid and the black paint were prepared and the black film was prepared in the same manner as in Example 1 except that the amount of the colloidal tin A was 75 g. Was evaluated.
These results are summarized in Table 1.

<Example 3>
In the preparation of the black material dispersion liquid of Example 1, the black material dispersion liquid and the black paint were prepared and the black film was prepared in the same manner as in Example 1 except that the amount of the colloidal tin A was 300 g. Was evaluated.
These results are summarized in Table 1.

<Example 4>
In the preparation of the black material dispersion liquid of Example 1, except that 150 g of tin colloid A was used, 450 g of tin colloid B (average particle size: 30 nm, solid content: 10% by mass, manufactured by Sumitomo Osaka Cement Co., Ltd.) was used. An aqueous dispersion of black fine particles (solid content: 25% by mass) was prepared in the same manner as in Example 1, and then a black material dispersion and a black paint were prepared and a black film was prepared using the same. Evaluation was performed.
These results are summarized in Table 1.

<Example 5>
In the preparation of the black material dispersion liquid of Example 1, the black material dispersion liquid and the black film were prepared in the same manner as in Example 1 except that the amount of sodium borohydride was 0.3 g. Was evaluated.
These results are summarized in Table 1.

<Example 6>
In the preparation of the black material dispersion liquid of Example 1, except that the amount of sodium borohydride was changed to 2 g, the black material dispersion liquid and the black film were prepared in the same manner as in Example 1, and the same evaluation was performed. Went.
These results are summarized in Table 1.

<Example 7>
In the preparation of the black material dispersion liquid of Example 1, the black material dispersion liquid and the black film were prepared in the same manner as in Example 1 except that the amount of polyvinylpyrrolidone diluted to 1% by mass was changed to 60 g. The same evaluation was performed.
These results are summarized in Table 1.

<Comparative Example 1>
The silver nitrate 56g was melt | dissolved in the pure water, and 1500 g of silver nitrate aqueous solution (A liquid) was prepared. Further, 314 g of trisodium citrate dihydrate and 360 g of polyvinylpyrrolidone diluted to 1% by mass were dissolved in pure water to prepare 2500 g of an aqueous solution of trisodium citrate (G solution). Next, after liquid A was dropped into and mixed with liquid G, 500 g of an aqueous solution prepared by dissolving 10 g of sodium borohydride in pure water was dropped and mixed to obtain liquid H.
Next, the above H liquid was dropped and mixed in 4000 g of tin fine particle dispersion obtained by mixing 150 g of tin colloid A (average particle size: 20 nm, solid content: 10% by mass, manufactured by Sumitomo Osaka Cement Co., Ltd.) and pure water. Further, an aqueous solution in which 180 g of tartaric acid was dissolved in 2000 g of pure water was dropped into a mixed liquid of the tin fine particle dispersion and the H liquid and stirred to dissolve excess tin colloid. Thereafter, washing was carried out by centrifugation to prepare an aqueous dispersion of black fine particles (Liquid I, solid content: 25% by mass).

Thereafter, using the aqueous dispersion (I liquid) of the black fine particles, a black material dispersion and a black paint were prepared and a black film was prepared in the same manner as in Example 1, and the same evaluation was performed. FIG. 2 shows a spectral absorption spectrum of a dispersion in which a black material is dispersed. As shown in this figure, the absorption characteristic has an absorption peak near 420 nm on the short wavelength side of the visible light region, and although the absorption characteristic on the short wavelength side is good, the absorption on the long wavelength side is not sufficient. The color was not natural black but reddish brown.
These results are summarized in Table 1.

<Comparative example 2>
In the preparation of the black material dispersion of Example 1, the same procedure as in Example 1 was conducted except that the amount of trisodium citrate dihydrate was 78 g and the amount of polyvinylpyrrolidone diluted to 1% by mass was 60 g. A black material dispersion and a black paint were prepared, and a black film was prepared, and the same evaluation was performed.
These results are summarized in Table 1.

<Comparative Example 3>
The silver nitrate 56g was melt | dissolved in the pure water, and 1500 g of silver nitrate aqueous solution (A liquid) was prepared. Further, 157 g of trisodium citrate dihydrate and 180 g of polyvinylpyrrolidone diluted to 1% by mass were dissolved in pure water to prepare 2500 g of an aqueous solution of trisodium citrate (solution B). Next, after the A liquid was dropped into and mixed with the B liquid, 500 g of an aqueous solution obtained by dissolving 20 g of sodium borohydride in pure water was dropped and mixed. By precipitating fine particles, an aqueous dispersion of fine particles of silver (solid content: 25% by mass) was prepared.

Thereafter, in the same manner as in Example 1 except that the silver fine particle aqueous dispersion was used instead of the black fine particle aqueous dispersion in Example 1, the preparation of the black material dispersion and the black paint, and the black film The same evaluation was performed.
These results are summarized in Table 1.

<Comparative example 4>
The silver nitrate 56g was melt | dissolved in the pure water, and 1500 g of silver nitrate aqueous solution (A liquid) was prepared. Further, 157 g of trisodium citrate dihydrate and 180 g of polyvinylpyrrolidone diluted to 1% by mass were dissolved in pure water to prepare 2500 g of an aqueous solution of trisodium citrate (solution B). Next, after dripping and mixing A liquid in B liquid, 500 g of aqueous solution which melt | dissolved sodium borohydride 0.2g in the pure water was dripped and mixed in this, and also 500g of ascorbic acid 54g dissolved in the pure water. An aqueous solution of silver fine particles was allowed to stand after dropping and mixing, and silver fine particles were precipitated in the absence of tin colloid to prepare an aqueous dispersion of silver fine particles (solid content: 25% by mass).

Thereafter, in the same manner as in Example 1 except that the silver fine particle aqueous dispersion was used instead of the black fine particle aqueous dispersion in Example 1, the preparation of the black material dispersion and the black paint, and the black film The same evaluation was performed.
These results are summarized in Table 1.

<Comparative Example 5>
The same procedure as in Example 1 was used except that tin colloid A (average particle size: 20 nm, solid content: 10% by mass, manufactured by Sumitomo Osaka Cement Co., Ltd.) was used instead of the black fine particle aqueous dispersion in Example 1. A black material dispersion and a black paint were prepared, and a black film was prepared, and the same evaluation was performed.
These results are summarized in Table 1.

In Table 1, “silver tin” in the crystal phase column of * 1 indicates “silver tin intermetallic compound (Ag ₃ Sn, Ag ₄ Sn)”, and “silver tin” in the metal particle type column of * 2. And “silver tin alloy (silver tin intermetallic compound + tin solid solution silver + silver solid solution tin)”. In addition, “main” of * 3 indicates a shape of 80% by number or more of the observed particles.

  As shown in Table 1, the black material dispersion of the example had a small wavelength dependency of absorbance, and natural black color was obtained. The black light-shielding film has a high OD value, excellent light-shielding properties, low reflectivity, and excellent blackness, and was able to satisfy all of the properties of high light-shielding properties, blackness, and natural color black.

On the other hand, although Comparative Example 1 has a high light-shielding property, since the absorbance on the short wavelength side is high, the color is reddish and a natural black color cannot be obtained.
In Comparative Example 2, since the absorbance on the high wavelength side was higher than that on the short wavelength side, the color was bluish and a natural black color could not be obtained.
In Comparative Example 3, although the average absorbance of the liquid was high, the absorbance on the short wavelength side was high, so the color was reddish, and the shading was reduced when baked, so that satisfactory shading of the film could not be obtained.
In Comparative Example 4, although the wavelength dependency of the absorbance was small, the absorbance was low, and since the particles were large, the scattering was increased and the appearance became gray.
In Comparative Example 5, although the average absorbance was high and the wavelength dependency of the absorbance was small, tin was oxidized during firing to reduce the light shielding properties, so that satisfactory film light shielding properties could not be obtained.

  The black film of the present invention and the substrate with the black film using the same can be suitably used in a display element typified by a liquid crystal display element and an organic EL element, and an image display apparatus using the same. Moreover, the black material of the present invention, the black material dispersion using the black material, and the black paint can effectively provide the black film.

Claims (8)

It is composed of metal fine particles including fine particles containing at least silver element and tin element, the silver element content is 30% by mass or more and 99% by mass or less, and the average primary particle size corresponding to the circle diameter of the metal fine particles is 3 nm or more. A black material of 100 nm or less,
In the dispersion liquid in which the black material is dispersed so that the solid content is 0.0005% by volume in the dispersion medium, the average absorbance from 380 nm to 800 nm at an optical path length of 10 mm is 0.8 or more, and the absorbance at 420 nm. black material ratio d ₄₂₀ / d ₆₈₀ between the absorbance d ₆₈₀ in the d ₄₂₀ and 680nm is 0.6 to 2.5.   The metal fine particles are fine particles having a silver-tin alloy portion, mixed fine particles of fine particles having a silver-tin alloy portion and silver fine particles, mixed fine particles of fine particles having a silver-tin alloy portion and tin fine particles, fine particles having a silver-tin alloy portion The black material according to claim 1, wherein the black material is any one of a mixed fine particle of silver fine particles and tin fine particles, and a mixed fine particle of silver fine particles and tin fine particles.   The black material dispersion liquid which disperse | distributed the black material of Claim 1 or 2 in the dispersion medium.   The black material dispersion liquid according to claim 3, wherein an average dispersed particle diameter of the black material is 5 nm or more and 100 nm or less, and a 90% cumulative volume particle diameter is 1 µm or less.   A black resin composition comprising at least the black material according to claim 1 and a resin forming component or a resin component.   A black film comprising at least the black material according to claim 1 or 2 and a resin component. The black film according to claim 6, wherein the volume resistivity is 10 ¹¹ Ω · cm or more.   The base material with a black film which has the black film of Claim 6 or 7 on a base-material surface.

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