JP2012203083A - Visible and near-infrared light shielding black film, substrate with visible and near-infrared light shielding black film, and solid-state imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a visible and near-infrared light shielding black film which is superior to a conventional black film in the ability to shield visible light and a near-infrared light region and is suitable for applications requiring the ability to shield visible light and near-infrared light such as a light shielding film for solid-state imaging device, a substrate with the visible and near-infrared light shielding black film, and a solid-state imaging device.SOLUTION: There are provided the visible and near-infrared light shielding black film, the substrate with the visible and near-infrared light shielding black film, and the solid-state imaging device. The visible and near-infrared light shielding black film contains fine metal particles having an average primary particle size of 1 nm or more and 300 nm or less, and the fine metal particles are a mixture of substantially spherical particles and substantially rod-shaped particles, a mixture of substantially spherical particles and substantially plate-shaped particles, or a mixture of substantially spherical particles, substantially rod-shaped particles, and substantially plate-shaped particles.

Description

  The present invention relates to a visible near infrared light shielding black film having a shielding ability against visible light and near infrared light, a substrate with a visible near infrared light shielding black film, and a solid-state imaging device.

A solid-state imaging device usually includes a semiconductor substrate such as silicon in which photodiodes (light receiving portions) that are photoelectric conversion elements are two-dimensionally arranged, and red (R) and green (two-dimensionally arranged above each photodiode). G) and blue (B) color filters, and an on-chip microlens provided on the color filters for condensing incident light on a photodiode.
Here, a light-shielding film is provided in the peripheral region of the imaging unit (effective pixel region) of the solid-state imaging device in order to reduce dark current, prevent the dynamic range from decreasing, and stabilize the operation of the peripheral circuit. When light enters the peripheral area, noise is generated due to the above-described action, and the image quality as an image sensor is deteriorated, so this effect is prevented.
In addition, in order to reduce the influence between adjacent color filters and improve the image quality, a light shielding film provided on the color filter, a so-called black matrix, has been provided.

  In recent years, with the miniaturization of the pixel unit (size of the photoelectric conversion element) of the solid-state imaging device, it is required to reduce the thickness of the light shielding film. That is, with the miniaturization of pixels, in order to ensure the amount of light received by the photoelectric conversion element, from the upper surface (substrate surface) of the photoelectric conversion element formed on the semiconductor substrate such as a silicon wafer to the lower surface of the on-chip microlens. There is a need to reduce the thickness of the effective optical functional layer, and for example, a thickness of 4 μm has been required. For this reason, it is necessary to reduce the thickness of the light shielding film on the periphery of the imaging unit and the black matrix for the solid-state imaging device color filter.

  Here, the light shielding film used in the black matrix for the image display device is mainly required to have a light shielding property in the visible region, whereas the light shielding film for the solid-state imaging device or the black matrix has a light shielding property in the visible region. In addition, light shielding properties in the near infrared region are also required. The reason for this is that since infrared region light is not visible to the human eye, light shielding is not a problem in image display devices, whereas solid-state imaging devices are sensitive to infrared region light, so This is because noise is generated when the outside region light is not shielded. As described above, the light-shielding film for the solid-state image sensor and the black matrix for the solid-state image sensor color filter are required to satisfy both the light-shielding property and the thin film.

Conventionally, as a black material for forming a light-shielding film for a solid-state image sensor or a black matrix for a solid-state image sensor color filter (hereinafter, the light-shielding film and the black matrix may be collectively referred to as “light-shielding film”), a liquid crystal display Carbon black, titanium black, and the like similar to those for the device black matrix have been known. However, conventional black materials such as carbon black and titanium black do not have sufficient shielding ability against visible light and near infrared light. For this reason, when using a conventional black material to improve the light-shielding property of the light-shielding film for a solid-state imaging device, the content of the black material contained in the light-shielding film or the like is increased or the film thickness of the light-shielding film or the like is increased. It is necessary to ensure the shielding ability of visible light and near infrared light by increasing. However, when the content of the black material in the light-shielding film or the like is increased, the ratio of the resin component contained in the light-shielding film or the like is reduced, so that curing is insufficient during pattern formation, resulting in insufficient film strength or fineness. There is a problem that the pattern formation becomes insufficient. Further, when the film thickness of the light shielding film or the like is increased, there is a problem that the formation of a fine pattern becomes insufficient, and above all, it is difficult to reduce the thickness of the image sensor (for example, Patent Documents 1 and 2). reference).
Furthermore, black materials using metal fine particles have existed in the past, but only the light shielding in the visible range is high, and there are black materials containing metal fine particles that exhibit high shielding ability in both the visible range and the near infrared range. (For example, refer to Patent Documents 3 and 4).

JP 2007-115921 A JP 2010-106268 A JP 2006-087771 A JP 2006-227268 A

  In view of the above, the present invention has a shielding ability over visible light and near-infrared light regions that is superior to conventional black films, and has a shielding ability for visible light and near-infrared light such as a light-shielding film for a solid-state imaging device. It aims at providing the base material with a visible near-infrared light shielding black film and a visible near-infrared light shielding black film suitable for the required use. It is another object of the present invention to provide a solid-state imaging device having the visible / near infrared light shielding black film or the substrate with the visible / near infrared light shielding black film.

The above problems are solved by the present invention described below. That is, the present invention is as follows.
[1] Metal fine particles having an average primary particle diameter of 1 nm or more and 300 nm or less, and the metal fine particles in the film are a mixture of substantially spherical particles and substantially rod-like particles, substantially spherical particles and substantially plate-like particles, Or a mixture of substantially spherical particles, substantially rod-like particles and substantially plate-like particles.
[2] The visible particle according to [1], wherein an average primary particle diameter of the substantially spherical particles is 1 nm or more and 100 nm or less, and an average primary particle diameter of the substantially rod-like particles or substantially plate-like particles is 5 nm or more and 300 nm or less. Near infrared shielding black film.
[3] Any or all of the substantially spherical particles, substantially rod-like particles, and substantially plate-like particles are aggregated particles of the metal fine particles, and the average dispersed particle diameter in the film of the substantially spherical particles is 1 nm or more and 100 nm or less. The visible near-infrared shielding black film according to [1] or [2], wherein the average dispersed particle diameter in the film of the substantially rod-like particles or the substantially plate-like particles is 5 nm or more and 300 nm or less.
[4] The metal fine particles include platinum, gold, silver, copper, palladium, nickel, tin, cobalt, rhodium, iridium, iron, ruthenium, osmium, manganese, molybdenum, tungsten, niobium, tantalum, titanium, and bismuth. Visible near-infrared light shielding black film in any one of said [1]-[3] containing 1 type, or 2 or more types selected from a group.
[5] The visible optical near-infrared shielding black film has an optical density average of 1.0 or more at a wavelength of 400 nm to 1300 nm, an optical density at a wavelength of 555 nm of 1.0 or more, and an optical density at a wavelength of 1300 nm of 0.6 or more. The visible and near infrared shielding black film according to any one of the above [1] to [4].
[6] The visible near infrared light shielding black film according to any one of [1] to [5], wherein the volume resistivity is 10 ¹¹ Ω · cm or more.

[7] A substrate with a visible near-infrared light shielding black film on which the visible near-infrared light shielding black film according to any one of [1] to [6] is formed.
[8] The solid-state imaging device having the visible / near infrared light shielding black film according to any one of [1] to [6] or the substrate with the visible / near infrared light shielding black film according to [7]. .

  According to the present invention, the shielding ability over the visible light and near-infrared light region is superior to the conventional black film, and the shielding ability of visible light and near-infrared light such as a light-shielding film for a solid-state imaging device or a black matrix. Therefore, it is possible to provide a visible near-infrared light-shielding black film and a substrate with a visible near-infrared light-shielding black film that are suitable for applications that require the above. Moreover, the solid-state image sensor which has a base material with said visible near-infrared light shielding black film or visible near-infrared light shielding black film can be provided.

It is an image which shows the result of having observed a part of cross section of the black film of Example 1 by TEM. It is an image which shows the result of having observed a part of cross section of the black film of Example 2 by TEM.

[Visible near-infrared light shielding black film]
The visible near-infrared light shielding black film of the present invention (hereinafter sometimes simply referred to as “black film”) comprises metal fine particles having an average primary particle diameter of 1 nm or more and 300 nm or less, and the metal fine particles in the film Is a mixture of substantially spherical particles and substantially rod-like particles, a mixture of substantially spherical particles and substantially plate-like particles, or a mixture of substantially spherical particles, substantially rod-like particles and substantially plate-like particles.
Conventionally, black films using metal fine particles have existed, but only light shielding in the visible range is high, and there are black materials containing metal fine particles that show high shielding ability in both the visible range and the near infrared range. There wasn't. The present invention controls the wavelength of light absorption by defining the particle size and form of the metal fine particles, and exhibits high shielding ability both in the near infrared region in addition to the visible region.

  The reason why the average primary particle diameter is limited to 1 nm or more and 300 nm or less is that a desired visible / near-infrared light shielding black film can be easily formed by setting the average primary particle diameter within the above range. That is, if the average primary particle diameter is less than 1 nm, the amount of transmitted light may be increased and the desired blackness may not be obtained because it is too small compared to the wavelength of visible light or near infrared light. If the particle monster exceeds 300 nm, scattering may occur and it may be difficult to obtain a desired blackness, or unevenness on the surface of the black film may increase.

The average primary particle size is preferably 3 nm or more and 100 nm or less, more preferably 3 nm or more and 60 nm or less, further preferably 5 nm or more and 60 nm or less, and particularly preferably 10 nm or more and 40 nm or less.
Here, the average primary particle diameter is a diameter corresponding to a circle in which metal fine particles having various shapes are observed with a TEM (transmission electron microscope) and the obtained fine particles have the same area.

  Further, the shape of the metal fine particles in the black film is a mixture of substantially spherical particles and substantially rod-like particles, a mixture of substantially spherical particles and substantially plate-like particles, a mixture of substantially spherical particles, substantially rod-like particles and substantially plate-like particles, Must be one of the following. Thus, by including both substantially spherical particles and substantially rod-like particles and / or substantially plate-like particles, the light shielding property from the visible light region to the near infrared region can be improved.

Here, substantially spherical particles, substantially rod-like particles, and substantially plate-like particles were defined as follows from an image obtained by observing a black film with a TEM.
First, when the length of the longest portion of the metal fine particle observed in the TEM image is L and the length perpendicular to L is W, the substantially spherical particle and the substantially plate-like particle are L / W. (Hereinafter, also referred to as “aspect ratio”) is less than 2. That is, the substantially spherical particles and the substantially plate-like particles do not necessarily have to be completely circular on the TEM image (the shape transferred to the flat surface), but have a distorted circle, ellipse, polygon, or corner. It may be a polygonal shape or the like. For particles having a particle diameter smaller than about 40 nm, it is difficult to determine whether the particle diameter is substantially spherical or substantially plate-like from a TEM image, and plate-like particles having a size of several tens of nm are formed due to the manufacturing method. Were considered to be difficult, so the particles were made into substantially spherical particles. For particles having a particle diameter larger than about 40 nm, those in which the transmittance at the center of the particle is lower than that at the outer periphery of the particle in the TEM image (the center of the particle appears black compared to the outer periphery) are approximately spherical. On the other hand, in the TEM image, the particles having substantially the same transmittance at the particle central portion and the particle outer peripheral portion (the particle central portion and the outer peripheral portion are reflected with the same brightness) were substantially plate-like particles.
Next, it is assumed that the substantially rod-like particles have an aspect ratio of 2 or more in the metal fine particles observed in the TEM image.

  The average primary particle diameter of the substantially spherical particles in the black film is preferably 1 nm or more and 100 nm or less, more preferably 1 nm or more and 50 nm or less, and further preferably 3 nm or more and 40 nm or less. Moreover, the average primary particle diameter in the black film of the substantially rod-like particles and the substantially plate-like particles is preferably 5 nm or more and 300 nm or less, more preferably 5 nm or more and 100 nm or less, and 10 nm or more and 100 nm or less. More preferably.

Furthermore, the substantially spherical particles, substantially rod-like particles and substantially plate-like particles may be aggregated particles.
It is known that metal fine particles (nanometer-sized metal fine particles) having a particle diameter of about 1 nm to several hundreds of nm exhibit various colors due to metal surface plasmon absorption, and the black film of the present invention also absorbs this surface plasmon. This is because even if the particles are metal agglomerated particles, the same surface plasmon absorption can occur if the agglomerated particle diameter is about 1 nm to several hundreds of nm. In addition, when the size and shape of the metal fine particles change, the dielectric function changes and the wavelength of the light absorbed by the fine particles changes, but not the primary particles, but the size and shape changes of the aggregated particles also affect the dielectric function, This is because the wavelength of light to be absorbed may be changed.
Here, “aggregated particles” refers to those that can be observed as agglomerated in a TEM image.

And even when these substantially spherical particles, substantially rod-like particles and substantially plate-like particles are agglomerated particles, the average dispersed particle diameter of the substantially spherical particles in the black film is preferably 1 nm or more and 100 nm or less, It is more preferably 1 nm or more and 50 nm or less, and further preferably 3 nm or more and 40 nm or less. Further, the average dispersed particle size of the substantially rod-like particles and substantially plate-like particles in the black film is preferably 5 nm or more and 300 nm or less, more preferably 5 nm or more and 100 nm or less, and more preferably 10 nm or more and 100 nm or less. More preferably.
The “average dispersed particle size in the film” has the same meaning as the average dispersed particle size in the dispersion. That is, if the particles in the film are only aggregated particles, the average value of the particle size of the aggregated particles, and if the aggregated particles and primary particles are mixed, the average value of the particle size of the combined particles If it is only primary particles (particles are not aggregated), it is the average value of the particle diameters of the primary particles.

The primary particles forming the aggregated particles are not particularly limited in shape, and may be any of substantially spherical metal fine particles, substantially rod-like metal fine particles, and substantially plate-like metal particles, or a mixture of these metal fine particles. Also, other shapes such as an elliptical sphere and a prismatic shape may be used.
Moreover, as a form of aggregation in the aggregated substantially rod-shaped particles, it is preferable that the primary particles are continuously connected. For example, a form in which two or more metal fine particles are connected in a straight line can be mentioned. Their presence can be confirmed by TEM.

  Then, the ratio of the volume of substantially spherical particles << A >> in the black film, the volume of substantially rod-like particles << B >>, and the volume of substantially plate-like particles << C >> (<< A >>: (<< B >> + << C >>)) is preferably 5:95 or more and 95: 5 or less, more preferably 10:90 or more and 90:10 or less.

  In the case of metal fine particles, the wavelength at which light is absorbed can be adjusted by controlling the particle diameter and particle shape. Therefore, in order to obtain desired visible light and near-infrared light shielding ability, particles having various particle sizes and particle shapes can be combined. In the present invention, the combination of the above-mentioned dispersed particle size range and particle shape can provide metal fine particles exhibiting a high shielding ability in both the visible region and the near infrared region, and thus in both the visible region and the near infrared region. A black film showing a high shielding ability can be obtained.

The visible near infrared light shielding black film of the present invention preferably has an average optical density of 1.0 or more at a wavelength of 400 nm to 1300 nm. The optical density is also called an OD value (Optical Density), and the optical density = −log ₁₀ T (T: transmittance) (Formula-1)
It is represented by

The average optical density at wavelengths from 400 nm to 1300 nm is obtained by, for example, measuring the transmittance at wavelengths of 400 nm to 1300 nm at 1 nm intervals with a spectrophotometer and converting the transmittance at each wavelength to optical density according to the above (formula-1). The optical density converted in the wavelength range of 400 nm to 1300 nm may be averaged. When the average optical density at wavelengths from 400 nm to 1300 nm is 1.0 or more, the visible and near-infrared light shielding black film absorbs light with visible light and near-infrared light.
The average optical density at wavelengths from 400 nm to 1300 nm is preferably 1.0 or more, more preferably 1.4 or more, further preferably 1.6 or more, and 1.8 or more. Particularly preferred.

The visible and near infrared light shielding black film of the present invention preferably has an optical density of 1.0 or more at a wavelength of 555 nm. When the optical density at a wavelength of 555 nm is 1.0 or more, the visible / infrared light shielding black film absorbs light with visible light.
The optical density at a wavelength of 555 nm is more preferably 1.4 or more, further preferably 1.6 or more, and particularly preferably 2.0 or more.

The visible and near infrared light shielding black film of the present invention preferably has an optical density of 0.6 or more at a wavelength of 1300 nm. When the optical density at a wavelength of 1300 nm is 0.6 or more, the visible near-infrared light shielding black film absorbs light with near-infrared light.
The optical density at a wavelength of 1300 nm is more preferably 1.0 or more, further preferably 1.2 or more, and particularly preferably 1.5 or more.

The film thickness of the visible near infrared light shielding black film of the present invention is preferably 5 μm or less. For example, in a color filter for a solid-state imaging device, both improvement in light shielding properties and thinning of the film are required (see, for example, JP-A-2010-008655), and it is not preferable to exceed 5 μm. The film thickness is more preferably 3 μm or less, and further preferably 2 μm or less.
Since the black film of the present invention has excellent light-shielding properties in the visible region and the near-infrared region, the light-shielding properties in the visible region and the near-infrared region can be made excellent even when the film thickness is thin.

  The fine metal particles in the present invention are selected from the group consisting of platinum, gold, silver, copper, palladium, nickel, tin, cobalt, rhodium, iridium, iron, ruthenium, osmium, manganese, molybdenum, tungsten, niobium, tantalum, titanium, and bismuth. It is preferable to include one or more selected, more preferably one or more selected from the group consisting of silver, copper, nickel, tin, cobalt, and iron, and silver, copper More preferably, they are 1 type, or 2 or more types selected from the group consisting of nickel, tin.

Among the metal fine particles, (1) silver or an alloy containing silver and a mixture thereof are particularly preferable.
Silver is visible light and near-infrared light, and the real part of the dielectric constant is negative, and has excellent light absorption characteristics. Conventionally, it has been known that metal fine particles (nanometer-sized metal fine particles) having a particle diameter of about 1 nm to several hundreds of nanometers exhibit various color tones due to metal surface plasmon absorption. It is also known to change depending on the composition and particle size. Since silver is a nanometer-sized metal fine particle and has high plasmon absorption in the visible light region, silver or an alloy containing silver and a mixture thereof are preferable.

Among the above metal fine particles, (2) those containing silver and a silver tin alloy part are particularly preferable.
Silver has excellent absorption characteristics by itself, but if the visible and near-infrared light-shielding black material is composed only of silver fine particles, the reflectivity will increase and the blackness will decrease, or it will be tens of degrees In some cases, the absorption spectrum may change due to the firing of, and the OD value may decrease. By alloying the metal fine particles, the movement of electrons is hindered by the scattering effect generated by alloying as compared with the case of a single metal, and therefore the reflectance of the black light-shielding film can be lowered.

In the present invention, the silver-tin alloy part is, for example, the following, which has a crystal structure of silver-tin intermetallic compound (hereinafter also referred to as “silver-tin intermetallic compound phase”), as well as silver Those having a crystal structure (hereinafter also referred to as “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 the silver phase, that is, having a silver crystal structure, a solid solution of tin in a state where the silver crystal structure is maintained in silver, that is, a part of silver atoms in the silver crystal is tin atoms. 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 (shown by the following notation is used) (Space group: 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 phase, and thus is excluded from the specified range as the silver-tin alloy part shown here. However, as the metal fine particles in the black film of the present invention, silver or an alloy containing silver and a mixture thereof are particularly preferable as described above. Therefore, the black film may contain Y = 0.

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 metal fine particles has not been found so far. The silver-tin alloy was successfully produced while controlling the particle diameter and particle shape by strictly controlling the reaction conditions.
By including silver tin alloy fine particles in the metal fine particles, it is possible to obtain a good balance between light shielding properties, blackness, and wavelength dependency of absorbance.
When a silver tin alloy having excellent blackness and heat resistance is added to silver having excellent absorption characteristics, a preferable visible near-infrared light shielding black material having both absorption characteristics and blackness can be obtained.

The content of the silver element in the metal element constituting the visible near infrared light shielding black material is preferably 30% by mass or more and 100% by mass or less. The content of silver element in the metal fine particles can be measured by, for example, EPMA (electron beam microanalyzer). The content of silver element in the metal fine particles can be calculated from the measured value of EPMA by the sum of the weight of silver element / weight of metal element. The denominator of the previous formula does not contain elements other than metals, such as carbon caused by a dispersant or the like adhering to the periphery of metal fine particles, oxygen caused by oxidation of the surface of metal fine particles, and the like.
The silver element content is usually often obtained by wet chemical analysis such as ICP emission analysis. However, if only the metal element is analyzed, it can be measured without problems even if EPMA is used.

  The content of the silver element in the metal fine particles is preferably 45% by mass or more and 100% by mass or less, more preferably 60% by mass or more and 100% by mass or less, further preferably 70% by mass or more and 100% by mass or less, and 70 A mass% or more and 95 mass% or less is particularly preferable.

The visible near infrared light shielding black film of the present invention preferably further contains a resin component.
As the resin component in the present embodiment, the metal fine particles are cured in a state of being uniformly dispersed in a state having the dispersed particle size and particle shape, and are suitable for characteristics required for the formed black film. You can select the one you want. As such a resin component, various kinds of ionizing radiation curable resins, thermosetting resins, thermoplastic resins and the like can be used.

The ionizing radiation curable resin means a resin that is cured by crosslinking or polymerization reaction by irradiation with electromagnetic waves or charged particle beams such as ultraviolet rays or electron beams, and is a radical polymerization type acrylic resin. And unsaturated polyester resins, cationic polymerization type epoxy resins, vinyl ether resins, oxetanes, and glycidyl ethers.
Examples of the acrylic resin include polyester (meth) acrylate, epoxy (meth) acrylate, urethane (meth) acrylate, polyol (meth) acrylate, and silicone (meth) acrylate.
Also, poly (meth) such as polymethyl (meth) acrylate, polycyclohexyl (meth) acrylate, polyethylene glycol di (meth) acrylate, poly-trimethylolpropane tri (meth) acrylate, and poly-pentaerythritol tetra (meth) acrylate Acrylic ester resins and the like can be mentioned.
Here, “(meth) acrylate” means “acrylate or methacrylate”. The same applies hereinafter.

Thermosetting resins include phenolic resin, phenol-formalin resin, urea resin, urea-formalin resin, melamine resin, polyester-melamine resin, melamine-formalin resin, alkyd resin, epoxy resin, epoxy-melamine resin, unsaturated polyester. Examples thereof include resins, polyimide resins, acrylic resins, polysiloxane resins, polyurethane resins, general-purpose two-component curable acrylic resins (acrylic polyol cured products), and the like.
Among these, glycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol diglycidyl ether, phenol novolac epoxy resin, cresol novolac epoxy resin, bisphenol epoxy resin, tris Henolmethane type epoxy resin, glycidyl (meth) acrylate and styrene copolymer epoxy resin, glycidyl (meth) acrylate, styrene and methyl (meth) acrylate copolymer epoxy resin, glycidyl (meth) acrylate and cyclohexylmaleimide Examples thereof include a copolymer epoxy resin and a fluorene epoxy resin.

Furthermore, as the thermoplastic resin, polyester resin, alkyd resin, polyurethane, polyvinyl pyrrolidone, polyvinyl alcohol and the like are preferably used.
Among these, the polyester resin is not limited as long as it is generally used in paints. For example, polyvalent carboxylic acids such as adipic acid, sebacic acid, isophthalic acid, and ethylene glycol, trimethylolpropane, etc. Examples include polycondensates of polyhydric alcohols. Also, the polyurethane resin is not limited as long as it is generally used in paints. For example, a polyurethane resin obtained by reacting an isocyanate group with a polyol to extend the chain is preferable. Examples of the polyol include polyester polyol, polyether polyol, and acrylic polyol.
When the black film of the present invention is used as a black matrix or the like, an alkali-soluble resin is selected as a resin forming component that is a raw material of the resin component, and a resin formed using this resin forming component is used as the resin component. It is preferable.

The black film of the present invention contains at least metal fine particles having an average primary particle diameter of 1 nm or more and 300 nm or less. The metal fine particles have high light absorption performance in the visible region and near infrared region, and are excellent in dispersibility in the resin.
Visible near-infrared having an optical density average of 1.0 or more, wavelength 555 nm of optical density of 1.0 or more, and optical density at wavelength of 1300 nm of 0.6 or more. In order to obtain a light shielding black film, the volume fraction of the metal fine particles in the black film is preferably 2% by volume or more and 50% by volume or less.

  When the volume fraction of the metal fine particles in the black film is 2% by volume or more, sufficient light shielding properties can be easily obtained in the visible region and the near infrared region. By controlling the volume to 50% by volume or less, a decrease in blackness due to an increase in reflectance due to metal fine particles is suppressed, and a decrease in film hardness and a development pattern accuracy failure due to a decrease in the resin component content ratio are prevented. be able to.

As described above, the volume fraction of the metal fine particles in the black film is preferably 2% by volume or more and 50% by volume or less, more preferably 2% by volume or more and 30% by volume or less, and more preferably 2% by volume or more and 20% by volume or less. Is more preferable, and 5 volume% or more and 15 volume% or less are especially preferable.
The volume fraction of the metal fine particles in the black film of the present embodiment can be determined from the masses of the black material and the resin forming component used as raw materials since the specific gravity of each of the black material and the resin component is known.

  Further, the conductivity of the black film can be controlled by the volume fraction of the metal fine particles in the black film. Although the metal fine particles themselves have conductivity, a resin component exists between the metal fine particles in the black film, and the resin component inhibits a conductive path between the metal fine particles. Furthermore, since the metal fine particles in the black film have a good dispersibility and are uniformly dispersed, the metal fine particles are not continuously connected to form a conductive path as in carbon black, for example. Therefore, when the ratio between the metal fine particles and the resin component in the black film is changed, the degree of inhibition of the conductive path between the metal fine particles by the resin is changed, so that the conductivity of the black film is changed. When it is desired to obtain a conductive black film, the volume fraction of the metal fine particles in the film is increased, and when it is desired to obtain an insulating black film, the volume fraction of the metal fine particles in the film may be decreased.

For example, the antireflection film of the solid-state imaging device may be required to have insulating properties. In this case, if the volume fraction of the metal fine particles in the black film is 2% by volume or more and 30% by volume or less, the volume resistivity is, for example, 10 ¹¹ Ω · cm while maintaining the light shielding property in the visible region and the near infrared region. As described above, a black film of 10 ¹³ Ω · cm or more can be obtained more preferably. Since the metal fine particles according to the present invention have excellent light-shielding properties in the visible region and near-infrared region, even if the volume fraction of the metal fine particles in the film is low, without increasing the film thickness, A black film having excellent light shielding properties in the infrared region, that is, a black film having the optical density can be obtained.

In order to obtain an insulating black film, the average particle diameter in the metal fine particle film is preferably 1 nm or more and 200 nm or less. In the present invention, since the average primary particle diameter of the metal fine particles used is 1 nm or more, it is difficult to exist as particles if the average particle diameter is less than 1 nm, while in the black film if the average particle diameter exceeds 200 nm. Therefore, it is difficult to secure a desired volume resistivity, and when the black material fine particles are agglomerated, the light shielding property is also lowered.
Therefore, in order to obtain an insulating black film, the average particle diameter in the film is preferably 2 nm or more and 200 nm or less, and more preferably 5 nm or more and 200 nm or less.

Moreover, the particle size distribution index D90% in the film of the metal fine particles in the black film is preferably 600 nm or less, and more preferably 500 nm or less. When the particle size distribution index D90% in the film is 600 nm or less, variation in particle diameter does not increase, and sufficient light shielding properties can be ensured while maintaining a desired volume resistivity.
Here, the particle size distribution index D90% in the film means a particle diameter (cumulative 90% diameter) corresponding to an accumulated value of 90% when the particle size is represented by a cumulative distribution, and exists in the film. This is an index indicating the uniformity of the particle diameter of the black material particles.
The lower limit value of D90% is not particularly defined, but since the lower limit value of the average particle diameter of the metal fine particles is 1 nm, it is difficult to make D90% less than 5 nm in the actual manufacturing process.

The average particle diameter of the metal fine particles in the film can be measured, for example, by cutting a film sample in a cross-sectional direction using FIB (focused ion beam) to make a thin piece, and observing the cut surface with a TEM.
In the present invention, a certain number of arbitrary particles (for example, 50 to 100 particles) are selected from the observation field, each particle image is approximated by a circle, and the diameter of the circle is defined as the particle diameter of the particle. The cumulative distribution of the diameter is obtained, and the particle diameter (median diameter) corresponding to the cumulative value of 50% is defined as the average particle diameter in the film. The particle size distribution index D90% can be obtained as a cumulative 90% diameter of the particle diameter of the selected particles.

The visible near-infrared light shielding black film of the present invention can be produced, for example, as follows.
First, the method for producing fine metal particles used in the black film of the present invention is not particularly limited as long as the above composition, dispersed particle size and dispersed particle shape can be obtained. Gas phase reaction method, spray pyrolysis Metal fine particle synthesis methods such as the method, liquid phase reaction method, freeze-drying method, hydrothermal synthesis method, etc. can be applied. Especially, as the metal fine particles, silver tin alloy fine particles, or mixed fine particles of silver tin alloy fine particles and silver fine particles In the case of selecting, it is preferable to use a liquid phase reaction method in which these fine particles can be easily obtained.

  As the liquid phase reaction method, it is preferable to use an aqueous reaction system. For example, a method of dropping a silver compound solution into a tin colloid dispersion and alloying tin and silver, or silver colloid and tin colloid By adding an oxidizing agent or a reducing agent to the dispersion in which silver coexists, silver tin alloy fine particles and silver fine particles can be generated using a method of alloying silver and tin. In this production method, the reaction conditions (for example, the ratio of tin and silver (silver ions), the pH of the reaction solution, the reaction temperature, the reaction time, the type and amount of the oxidizing agent and the reducing agent, etc.) are appropriately adjusted. The production amount of silver tin alloy fine particles, the production amount of silver fine particles (including the case where substantially no silver tin alloy fine particles are produced, that is, the case where only silver tin alloy fine particles are produced), the production amount ratio of silver tin alloy fine particles and silver fine particles Furthermore, the shape of the particles can be controlled as necessary.

In the present invention, the particle diameter and shape of the obtained metal fine particles are in the above-mentioned range, that is, the average primary particle diameter is 1 nm or more and 300 nm or less, and the shape of the metal fine particles in the film is substantially spherical particles and substantially rod-shaped particles. There are the following methods for obtaining metal fine particles that are a mixture, a mixture of substantially spherical particles and substantially plate-like particles, or a mixture of substantially spherical particles, substantially rod-like particles and substantially plate-like particles.
First, as a method for controlling the particle diameter and shape of the metal fine particles themselves, by adjusting the various conditions (manufacturing conditions) in the liquid phase reaction method, substantially spherical particles and substantially rod-like particles, and substantially spherical particles and substantially plate-like shapes. Examples thereof include a method of simultaneously forming any one of particles, substantially spherical particles, substantially rod-like particles, and substantially plate-like particles. However, in order to form particles having a plurality of shapes at the same time, it is necessary to strictly control the production conditions. Therefore, an easier method is to form a substantially rod-like particle and / or a substantially plate-like particle by a liquid phase reaction method, and then add a metal ion and a reducing agent under the conditions for further producing a substantially spherical particle. A method for producing spherical particles is mentioned. The substantially spherical particles may be first generated, and then the substantially rod-like particles and / or the substantially plate-like particles may be generated.
Furthermore, after substantially spherical particles, substantially rod-like particles and substantially plate-like particles are produced separately, substantially rod-like particles and / or substantially plate-like particles are mixed with the substantially spherical particles to obtain target metal fine particles. it can.

Next, when the substantially rod-like particles or the substantially plate-like particles are aggregated particles, it is not always necessary to control the particle diameter and shape of the other metal fine particles themselves as long as the substantially spherical particles are obtained. The reason is that substantially spherical particles may be aggregated to form substantially rod-like particles or substantially plate-like particles.
Similarly, when the substantially spherical particles are aggregated particles, it is not always necessary to control the particle diameter and shape of the substantially spherical particles themselves as long as the substantially rod-like particles and / or the substantially plate-like particles are obtained. This is because substantially rod-like particles or substantially plate-like particles may be aggregated to form substantially spherical particles.
Further, when all of the substantially spherical particles, substantially rod-like particles, and substantially plate-like particles are aggregated particles, the metal fine particles themselves can be used as long as the metal fine particles that are primary particles constituting these aggregated particles are obtained. It is not always necessary to control the particle size and shape. This is because the metal fine particles (primary particles) may be aggregated to form substantially spherical particles, substantially rod-like particles, and substantially plate-like particles.

  In addition, the fine metal particles are dispersed in the resin component, and the dispersion state of the fine metal particles is controlled to form substantially spherical, substantially rod-like, substantially plate-like aggregate particles, and the affinity between the fine metal particles and the resin component. In order to improve the properties, it is preferable that the surface of the metal fine particles is surface-treated with a surface treatment agent or a dispersant (hereinafter, sometimes referred to as “dispersant etc.”). These surface treatment agents and dispersants may be selected from known materials in accordance with the material of the resin component and the method of dispersing the metal fine particles in the resin component. The visible near infrared light shielding black film of the present invention can be obtained by adjusting the dispersion method and dispersion conditions together with the type of the dispersant, and dispersing the metal fine particles in the resin component.

As the dispersant, a polymer dispersant is preferable. For example, urethane dispersant, modified polyester dispersant, polycarboxylate, polyalkyl sulfate, polyvinyl pyrrolidone (PVP), polyvinyl alcohol (PVA), polyacrylamide. Etc. In addition, as the structure of the polymer dispersant, a random copolymer, a comb copolymer, an ABA copolymer, a BAB copolymer, a polymer having a hydrophilic group at both ends, a polymer having a hydrophilic group at one end, etc. can be selected. In view of the high dispersibility, random copolymers and comb copolymers are preferred.
Specific examples of the dispersant include EFKA (manufactured by EFKA Chemicals Beebuy (EFKA)), Disperbyk (manufactured by Big Chemie), Disparon (manufactured by Enomoto Kasei Co., Ltd.), SOLPERSE (manufactured by GENEKA), and KP (manufactured by Shin-Etsu Chemical). ), Polyflow (manufactured by Kyoeisha Chemical Co., Ltd.) and the like.

  Examples of the surface treatment agent include coupling agents such as a silane coupling agent and a titanium coupling agent.

In the surface treatment, the amount of the dispersant or the like that binds to the surface of the metal fine particles is preferably in the range of 2 to 30% by mass with respect to the amount of metal fine particles. Further, there are more suitable ranges depending on the composition of the metal fine particles, the primary particle diameter, and the composition of the resin component raw material in which the metal fine particles are dispersed and mixed. The reason for this is that in the case of forming a coating film from a black paint formed using this metal fine particle, and further forming a visible near-infrared light shielding black film, in the coating film or in the visible near-infrared light shielding black film In order to ensure the dispersibility of the metal fine particles in the interior and, in some cases, to obtain the agglomerated particles of the metal fine particles within the range satisfying the present invention, it is necessary to strictly adjust the amount of the dispersant added to the metal fine particles. Because there is.
That is, when the amount of the dispersant or the like is too small, a portion with a small coating amount of the dispersant or the like is formed on a part of the surface of the metal fine particles, and the affinity for the resin component raw material or solvent in the portion is reduced. On the other hand, since the affinity between the metal fine particles remains, after the metal fine particles are dispersed in the resin component raw material or the solvent, the metal fine particles are aggregated from a portion where the coating amount of the polymer dispersant or the like is small. There is a risk of forming.

On the other hand, when the amount of the polymer dispersant or the like is excessive, the dispersant itself may be a factor for reducing the dispersibility. Furthermore, when the resin component raw material is cured to form a visible near-infrared light-shielding black film, an excessive polymer dispersant or the like inhibits the curing due to the polymerization of the resin component raw material, thereby obtaining sufficient film strength. There is a risk of being lost. In addition, when a photoresist or the like is used for the cured resin, developability may be deteriorated in the development step after exposure with light.
In addition, when the substantially spherical particles, substantially rod-like particles, or substantially plate-like particles according to the present invention are single particles, the amount of the dispersant or the like that binds to the surface of the metal fine particles is 5 to 30 with respect to the amount of the metal fine particles. More preferably, it is in the range of 2% by mass. On the other hand, when at least a part of the substantially spherical particles, the substantially rod-like particles and the substantially plate-like particles are agglomerated particles, it is more preferably in the range of 2 to 25% by mass. preferable.

As described above, in order to strictly adjust the addition amount of the dispersant and the like to the metal fine particles, the metal is added by adding the dispersant and the like to the aqueous solvent in which the metal fine particles having a hydrophilic surface are dispersed and stirring the metal. After the surface of the fine particles is coated with a dispersant or the like, it is preferable to dry the metal fine particles using a method of removing only the solvent, for example, an evaporator or the like. In this way, a designed amount of dispersant or the like can be used for the metal fine particles.
Furthermore, even if the treatment of the dispersant is not uniform at the time of the surface treatment with the dispersant or the like, after the surface-treated metal fine particles are dispersed in the resin component raw material or a solvent highly compatible with the resin component raw material, Since the adsorption and desorption equilibrium of the dispersant and the like with respect to the metal fine particles can make the coating of the dispersant and the like with respect to each particle uniform, uniform dispersibility of the metal fine particles is also ensured.

Next, a black paint containing metal fine particles subjected to surface treatment with a dispersant or the like and a resin component raw material is prepared. Here, the resin component raw material is liquid and forms the resin component by curing, solvent distillation, etc. In addition to the resin component monomer, oligomer, prepolymer, the resin component is dissolved in the solvent. In addition, a resin component monomer, oligomer or prepolymer dissolved in a solvent is also included.
When the resin component monomer, oligomer, and prepolymer are in liquid form, the resin component monomer, oligomer, and prepolymer can be directly used as the resin component raw material, and metal fine particles can be mixed and dispersed therein to produce a black paint. Good. Also, a solution in which a resin component or solid resin component monomer, oligomer, or prepolymer is dissolved in an appropriate solvent to obtain a liquid, or a solution in which a liquid resin component monomer, oligomer, or prepolymer is diluted in a solvent. As a resin component raw material, metal fine particles may be mixed and dispersed therein to produce a black paint.
Further, the black paint may contain an additive described later.

  In the present invention, the metal fine particles that have been surface-treated with the above polymer dispersant or the like may be mixed and dispersed in the resin component raw material in the form of fine particles to form a black paint, or compatible with the resin component raw material in advance. A black paint may be formed by preparing a metal fine particle dispersion in which metal fine particles are dispersed in a high solvent and mixing the dispersion and the resin component raw material. In addition, you may dissolve the below-mentioned additive beforehand in this metal fine particle dispersion.

In the present invention, by imparting UV sensitivity to the resin component raw material, it is possible to form a black film having a complicated design and improved design by exposing and developing the coated and dried film. Is preferable. Moreover, it can also be used as a black resist for black pattern formation by using the resin component raw material which has ultraviolet photosensitivity.
Here, there are two types of ultraviolet photosensitivity: a negative type (the photosensitive part remains by development) and a positive type (the photosensitive part is removed by development). Both of the black films of the present invention can be applied. . However, the visible near-infrared light-shielding black film and the metal fine particles in the film have a light-shielding property against ultraviolet rays. Therefore, when the black film becomes thick, the bottom of the film is exposed at the exposure part (ultraviolet irradiation part). In some cases, the film is not sufficiently exposed. In order to prevent this influence, the negative type may be preferable.

  As the resin component raw material having ultraviolet photosensitivity, a commercially available resist material can be used, and a photoreactive agent may be added to the acrylic resin, epoxy resin, polyester resin, and polyurethane resin. As the commercially available resist material, those for liquid crystal or MEMS are preferably used. The reason for this is that a permanent film is obtained by performing a treatment such as thermosetting on a film formed of these resist materials. This is because it becomes possible to form.

  Further, as a reaction initiator for curing these resin component raw materials, a material that initiates / accelerates polymerization of the resin component by generating radicals by heat or light may be added to the black paint. Thus, by giving photocurability to the resin component raw material, the resin component raw material can be handled as a negative resist.

  The solvent used for the resin component raw material and the solvent used for the metal fine particle dispersion are not particularly limited as long as the solubility of the resin component (raw material) used and the dispersibility of the metal fine particles can be maintained. For example, methanol, ethanol, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, methyl ethyl ketone, and methyl isobutyl A ketone etc. can be mentioned.

The mixed dispersion for obtaining the black paint or the metal fine particle dispersion is a known mixed dispersion such as an ultrasonic disperser, a paint shaker, a ball mill, a bead mill, an Eiger mill, etc. This can be done by performing distributed processing using a machine. In particular, a bead mill is preferable from the viewpoint of dispersibility.
Furthermore, when mixing fine metal particles, in addition to the addition of a solvent for adjusting the viscosity and dispersion state, the addition of the curing agent, the addition of a low molecular weight crosslinking agent for improving the hardness of the film, and the formation of visible A silane coupling agent or the like for improving the adhesion between the infrared light shielding black film and the coating substrate may be added within a range that does not deteriorate the characteristics of the visible near infrared light shielding black film to be formed.

The black paint thus obtained is applied onto a substrate to form a coating film.
As a substrate to be used, it may be selected according to the method of use and usage form of the visible and near infrared light shielding black film, and is not particularly limited.For example, in addition to a semiconductor substrate such as a silicon wafer, an inorganic substrate such as glass, If a substrate having high hardness such as an acrylic substrate or a polycarbonate substrate is used, a structure having a visible and near-infrared light shielding black film can be obtained. In addition, if a polymer film such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethylene sulfone (PES), or triacetyl cellulose (TAC) is used, flexible visible near infrared light A shielding black film can also be obtained.

  The coating method (coating film forming method) of the black paint is not particularly limited, but spin coating, flow coating, spray coating, dip coating, die coating, gravure coating, knife coating, Examples thereof include a bar coating method, a slit coating method, a slit & spin coating method, and an ink jet method.

A visible / near-infrared light-shielding black film can be obtained by curing the applied film or removing the solvent by volatilization. In addition, when obtaining a black film by the above-described curing, if a solvent is included in the black paint, the solvent in the coating film is first removed to form a coating dry film (a solid film is formed by removing the solvent). However, the polymerization and curing of the resin component hardly occur, and the coating film is cured after forming a film in a state where it can be dissolved in the solvent again by contacting with the solvent.
As a curing method, the monomer, oligomer, and prepolymer of the resin component raw material may be heated at a temperature at which thermal polymerization starts, and when a reaction initiator is added, heat or light corresponding to the reaction initiator is added. Application may be performed. Moreover, you may use both together. In addition, it may replace with hardening by reducing the re-solubility to a solvent by performing the solvent removal in the said coating film more completely (specifically solvent removal is performed at higher temperature).

Next, a method for obtaining a complicated shape by performing ultraviolet irradiation (exposure) and development on a coating film using a black paint containing a resin component material having ultraviolet sensitivity will be briefly described.
There is no particular limitation on the exposure method, but exposure can be easily performed by using a commercially available ultraviolet exposure device and a photomask as long as it has a planar shape. In addition, so-called direct drawing (direct drawing) can be performed in which an ultraviolet laser is used as the light source and a fine laser beam is scanned to directly write a pattern on the coated and dried film.
There is no particular limitation on the developing method, and a normal method such as a dip method or a paddle method may be used. These exposure and development conditions may be appropriately selected and adjusted according to the resin component raw material to be used and the required shape.
According to the above process, for example, a resist material is used as a resin component raw material, and a complex shape is obtained by exposing and developing a coated dry film, and a light shielding film for a solid-state imaging device described later and a black for an image display device are preferable. Mention may be made of matrices.

[Substrate with visible near infrared light shielding black film]
The base material with a visible near infrared light shielding black film of the present invention is formed by forming the visible near infrared light shielding black film of the present invention on the base material. The base material with a visible / near-infrared light-shielding black film is light transmissive if a black matrix for an image display device is formed on a semiconductor substrate such as a silicon wafer if a solid-state imaging device is formed. The visible near-infrared light shielding black film of the present invention is formed on a conductive substrate or the like by a known method and is patterned as necessary.

  Although it does not specifically limit as a base material, A silicon wafer, 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, but can be appropriately selected from 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), polyethylene naphthalate (PEN), polyether, polyimide, epoxy resin, phenoxy resin , Polycarbonate (PC), polyvinylidene fluoride, triacetylcellulose (TAC), polyethersulfone (PES), polyacrylate, and the like, which can be appropriately selected based on the use and use conditions.

The method of obtaining a complicated shape by patterning is not particularly limited, but the resin component raw material may be UV-sensitive as described above, and steps such as exposure and development may be performed.
When the patterning process such as exposure and development is applied as a black matrix for an image display device, for example, the method described in paragraphs 0096 to 0106 of JP-A-2006-251095, or JP-A-2006-251237. The method for forming a light-shielded image described in paragraph numbers 0116 to 0126 of the publication can also be suitably used in this embodiment.
The black film of the present invention can reduce the amount of black material particles in the black film because the blackness of the contained metal fine particles (black material) is high. That is, the resin component ratio in the black film is not reduced. Therefore, even when a complicated shape is obtained by patterning, there arises a problem that the formed black film is not sufficiently cured, the film strength is insufficient, or the fine pattern is not sufficiently formed. There is nothing.

There is also a method for producing a layer in which a pattern is directly formed on a substrate by using an ink jet method using a black paint. 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.

Since the substrate with a visible near-infrared light-shielding black film of the present invention has shielding properties over both the visible light region and the near-infrared light region, a black matrix (used for a color filter for a solid-state imaging device) A black matrix substrate provided with a light-shielding film can also be suitably used.
When used as a black matrix substrate for a color filter for a solid-state imaging device, the film thickness of the visible / near infrared light shielding black film is preferably 0.2 μm or more and 5.0 μm or less, more preferably 0.2 μm or more and 4.0 μm or less. preferable. Moreover, since the black film in the black matrix substrate uses the black film of the present invention, even a thin film has a high optical density.

[Solid-state imaging device]
The solid-state imaging device of the present invention has the visible / near-infrared shielding black film of the present invention or the substrate with the visible / near-infrared light shielding black film of the present invention.
Typical solid-state imaging devices include CCD (Charge Coupled Device) devices and CMOS (Complementary Metal Oxide Semiconductor) devices, but with the visible and near infrared light shielding black film and the visible near infrared light shielding black film of the present invention. The base material can be suitably used in various solid-state image sensors including these solid-state image sensors.

A solid-state imaging device usually includes a semiconductor substrate such as silicon in which photodiodes (light receiving portions) that are photoelectric conversion elements are two-dimensionally arranged, and red (R) and green (two-dimensionally arranged above each photodiode). G) and blue (B) color filters, and an on-chip microlens provided on the color filters for condensing incident light on a photodiode.
In the peripheral area of the imaging unit (effective pixel area) of the solid-state imaging device, noise is reduced and image quality is lowered as an image sensor by reducing the dark current, preventing the dynamic range from being lowered, and stabilizing the operation of the peripheral circuit. A light-shielding film is provided to prevent this. In some cases, a black matrix may be provided in the color filter in order to reduce the influence between adjacent color filters and improve the image quality.

  The black film of the present invention has a high blackness and a high light-shielding property for light from the visible region to the near-infrared region, and because of its high light-shielding property, it can be thinned. That is, it can be suitably used as a light-shielding film provided in the peripheral region of the imaging unit or a black matrix of a color filter. That is, even if the light shielding film and the black matrix are made thin in response to the reduction in the thickness of the effective optical functional layer from the upper surface of the photoelectric conversion element to the lower surface of the on-chip microlens due to pixel miniaturization A good light-shielding property. In addition, since the metal fine particles (black particles) contained therein have a small particle size and good dispersibility, the film has high homogeneity and good surface flatness. It is more suitable for use as a light-shielding film for a solid-state image pickup device without causing deterioration of image quality due to light-shielding unevenness or film surface roughness.

Furthermore, since the blackness of the contained metal fine particles (black material) is high, the amount of black material particles in the black film can be reduced, and since the particle size is small and the dispersibility is good, high volume resistivity is exhibited. Therefore, it is not necessary to newly form an insulating layer in order to provide the black film. For example, even when the black matrix and the image sensor itself are in direct contact with each other, there is no problem of malfunction due to a short circuit between the image sensors.
Furthermore, since the amount of black material particles in the black film is small, that is, the ratio of the resin component in the black film is not reduced, film curing is not sufficient even in a complex-shaped black film obtained by patterning. And the film strength is not insufficient, and the formation of the fine pattern is not insufficient. Therefore, since the black matrix for a solid-state image sensor color filter having a fine and accurate shape can be obtained, the characteristics of the solid-state image sensor can be further improved.

[Image display device]
Since the visible / near-infrared light-shielding black film and the substrate with visible / near-infrared light shielding black film of the present invention have good light-shielding properties against light in the visible region, they are not only for solid-state imaging devices but also for various images. It can be suitably used in a display device. Examples of the image display device include a self-luminous display device such as a plasma display display device and an EL display device, a CRT display device, a liquid crystal display device, and the like. In particular, the present invention is applied to a liquid crystal display device or an EL display device. The visible and near infrared light-shielding black film and the black film of the substrate with the visible and near infrared light shielding black film are remarkably exhibited. Here, examples of the liquid crystal display device include STN, TN, VA, IPS, OCS, and R-OCB.

  Since the black film of the present invention has high blackness and high volume resistivity, it is suitably used as a member for an image display device utilizing its light shielding property (non-reflecting property of light) and resistivity. be able to. 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.

Here, in black matrix and its application to color filters, it is possible to reduce the thickness of the black matrix due to its high blackness, and the resulting flatness of the color filter is high. In a liquid crystal display device provided with a filter, 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.
Further, since the volume resistivity is high, even when the black matrix and the pixel driving wiring are in contact with each other, such as a COA type or BOA type liquid crystal display element or a self-luminous display device, an element due to a short circuit of the wiring or the like There is no risk of driving failure.

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 measuring method and evaluation methods, such as the characteristic of a material and a sheet | seat which were employ | adopted in the Example or the comparative example, are 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, diffraction peaks at around 2θ = 38 ° and around 44 ° are silver, and peaks near 2θ = 34.7 ° and 39.7 ° are silver-tin intermetallic compounds (Ag3Sn and / or Ag4Sn). By identifying peaks near 2θ = 30.7 ° and near 32 ° as the crystal phase peak of tin, the crystal phase of the contained metal particle species was confirmed.

[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 to identify the fine particle species as containing tin, and the sample in which the crystalline phase of silver was confirmed by the XRD measurement By confirming the presence of silver by EPMA measurement, it was identified that the fine particle species contained silver.

・ Black film (optical density (film shading))
The transmittance of the substrate with the black film was measured at 1 nm intervals using a spectrophotometer (V-570, manufactured by Jusco Engineering). The measured transmittance is
Optical density was converted to optical density by the formula: -log ₁₀ T (T: transmittance).
The optical densities from 400 nm to 1300 nm converted at 1 nm intervals were averaged to obtain an average optical density from 400 nm to 1300 nm. The optical density at 555 nm and 1300 nm was recorded.

(Average primary particle size, average dispersed particle size, particle size distribution index of black material particles in black film)
The prepared black film sample was cut into thin sections by cutting in the cross-sectional direction using FIB (focused ion beam), and the cut surface was observed with a transmission electron microscope (TEM: JEM-2010, JEM-2010). The shape and aspect ratio of the fine particles were determined from the observation field image. 100 arbitrary primary particles were selected from the observation field, each particle image was approximated by a circle, and the average primary particle size and particle size distribution were calculated using the diameter of the circle as the particle size of the particle.
In addition, 100 arbitrary particles were selected from the observation field, each particle image was approximated by a circle, and the average dispersed particle size and particle size distribution were calculated using the diameter of the circle as the particle size of the particle. Here, “arbitrary particles” include aggregated particles and primary particles that are not aggregated. That is, if the particles in the black film are only agglomerated particles, the agglomerated particles, if the agglomerated particles and the primary particles coexist, the combined particles, if the only primary particles (particles are not agglomerated) Primary particles are shown.

(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>
(Synthesis of nearly spherical particles)
Silver nitrate 56g was melt | dissolved in the pure water, and 1500 g of silver nitrate aqueous solution (A1-1 liquid) was prepared. In addition, 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 a trisodium citrate aqueous solution (B1-1 solution). Next, the A1-1 solution was dropped into and mixed with the B1-1 solution, and then 500 g of an aqueous solution in which 10 g of sodium borohydride was dissolved in pure water was dropped and mixed to obtain a C1-1 solution. .

  Next, the C1-1 solution was added dropwise to 4000 g of tin fine particle dispersion obtained by mixing 150 g of tin colloid (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 the mixed liquid of the tin fine particle dispersion and the C1-1 liquid and stirred to dissolve excess tin colloid. Thereafter, washing was performed by centrifugal separation to prepare an aqueous dispersion of black fine particles (D1-1 solution, solid content: 25% by mass).

(Synthesis of substantially rod-shaped particles)
Silver nitrate 56g was melt | dissolved in the pure water, and 1500 g of silver nitrate aqueous solution (A2-1 liquid) was prepared. Further, 78 g of trisodium citrate dihydrate and 60 g of polyvinylpyrrolidone diluted to 1% by mass were dissolved in pure water to prepare 2500 g of an aqueous solution of trisodium citrate (B2-1 solution). Next, after the A2-1 solution was dropped into the B2-1 solution and mixed, 500 g of an aqueous solution obtained by dissolving 0.1 g of sodium borohydride in pure water was dropped and mixed, and 18 g of ascorbic acid was further added. 500 g of an aqueous solution dissolved in pure water was dropped and mixed to obtain a C2-1 solution.

  Next, the C2-1 solution was dropped and mixed in 4000 g of tin fine particle dispersion obtained by mixing 150 g of tin colloid (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 C2-1 liquid and stirred to dissolve excess tin colloid. Thereafter, washing was performed by centrifugation to prepare an aqueous dispersion of black fine particles (D2-1 solution, solid content: 25% by mass).

(Preparation of black material dispersion)
Next, after mixing 30 g of the D1-1 solution, 70 g of the D2-1 solution, 3.75 g of the comb-shaped urethane polymer dispersant, and 34 g of methyl ethyl ketone, water and methyl ethyl ketone were evaporated from the mixture using an evaporator, and dried powder ( E-1 powder) was obtained.
Next, 29 g of the above E-1 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 (F-1 solution, solid content: 25% by mass). Got.

(Production of black film)
A black material dispersion (F-1 solution), a resist (dispersion medium: PGMEA) containing polyfunctional acrylate as a resin-forming component, and PGMEA as a solvent have a solid content volume ratio (black fine particles: resist) of 7.5: It mixed so that it might become 92.5, and was disperse | distributed by the ultrasonic treatment and it was set as the black coating material (G-1 coating material). In addition, the said solid content volume ratio is a preparation ratio.
Next, the G-1 paint prepared above 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. And the glass substrate with a black film (H-1 film) of Example 1 was obtained. The film thickness of the black film was 1 μm. In addition, in FIG. 1, a part of the black film of Example 1 was cut into thin sections by cutting in the cross-sectional direction using FIB, and observed with TEM (manufactured by JEOL Ltd., JEM-2010) (400,000 times) Indicates.

(Evaluation)
The black material and black film obtained above were measured for the composition of the fine particles, the particle shape in the film, the aspect ratio, the dispersed particle diameter, the optical density and the like according to the above conditions. The results are shown in Table 1.

[Example 2]
After mixing 30 g of D1-1 solution, 70 g of D2-1 solution, 2.5 g of comb urethane polymer dispersant and 22.5 g of methyl ethyl ketone used in Example 1, water and methyl ethyl ketone were evaporated from the mixture using an evaporator. As a result, dry powder (E-2 powder) was obtained.
Next, 29 g of the E-2 powder and 71 g of propylene glycol monomethyl ether acetate (PGMEA) were mixed and dispersed using a bead mill, and a black material dispersion (F-2 solution, solid content: 25 mass%) Got.
Subsequent steps were performed in the same manner as in Example 1, and a black film (H-2 film) in Example 2 was produced. FIG. 2 shows the result (400,000 times) of observation of a part of the black film of Example 2 by TEM in the same manner as in Example 1.
The physical properties of the produced black fine particles and black film were evaluated in the same manner as in Example 1. These results are shown in Table 1.

[Example 3]
The black metal fine particle dispersion F-1 solution (solid content: 25% by mass) used in Example 1, a resist (dispersion medium: PGMEA) having a polyfunctional acrylate as a resin-forming component, and PGMEA as a solvent were used as a solid content. It added so that volume ratio (black fine particle: resist) might be set to 10:90, and it disperse | distributed by ultrasonic treatment, and was set as the black coating material (G-3 coating material). In addition, the said solid content volume ratio is a preparation ratio.
Subsequent steps were performed in the same manner as in Example 1, and a black film (H-3 film) in Example 3 was produced. The physical properties of the produced black fine particles and black film were evaluated in the same manner as in Example 1. These results are shown in Table 1.

[Example 4]
The black metal fine particle dispersion F-1 solution (solid content: 25% by mass) used in Example 1, a resist (dispersion medium: PGMEA) having a polyfunctional acrylate as a resin-forming component, and PGMEA as a solvent were used as a solid content. It added so that volume ratio (black fine particle: resist) might be set to 30:70, and it disperse | distributed by ultrasonic treatment, and was set as the black coating material (G-4 coating material). In addition, the said solid content volume ratio is a preparation ratio.
Subsequent steps were carried out in the same manner as in Example 1, and a black film (H-4 film) in Example 4 was produced. The physical properties of the produced black fine particles and black film were evaluated in the same manner as in Example 1. These results are shown in Table 1.

[Example 5]
The black metal fine particle dispersion F-1 solution (solid content: 25% by mass) used in Example 1, a resist (dispersion medium: PGMEA) having a polyfunctional acrylate as a resin-forming component, and PGMEA as a solvent were used as a solid content. It added so that volume ratio (black fine particle: resist) might be set to 3:97, and it disperse | distributed by ultrasonic treatment, and was set as the black coating material (G-5 coating material). In addition, the said solid content volume ratio is a preparation ratio.
Subsequent steps were carried out in the same manner as in Example 1, and a black film (H-5 film) of Example 5 was produced. The physical properties of the produced black fine particles and black film were evaluated in the same manner as in Example 1. These results are shown in Table 1.

[Example 6]
A black film (H-6 film) of Example 6 was produced in the same manner as in Example 1 except that the G-5 paint of Example 5 was used and the film thickness was changed to 2 μm. The physical properties of the produced black fine particles and black film were evaluated in the same manner as in Example 1. These results are shown in Table 1.

[Example 7]
A black film (H-7 film) of Example 7 was produced in the same manner as in Example 1 except that the G-5 paint of Example 5 was used and the film thickness was changed to 5 μm. The physical properties of the produced black fine particles and black film were evaluated in the same manner as in Example 1. These results are shown in Table 1.

[Example 8]
After mixing D1-1 liquid 10g, D2-1 liquid 90g, comb-shaped urethane polymer dispersant 3.75g and methyl ethyl ketone 34g used in Example 1, water and methyl ethyl ketone were evaporated from the mixture using an evaporator, Dry powder (E-8 powder) was obtained.
Next, 29 g of the E-8 powder and 71 g of propylene glycol monomethyl ether acetate (PGMEA) were mixed and dispersed using a bead mill, and a black material dispersion (F-8 liquid, solid content: 25 mass%) Got.
Subsequent steps were performed in the same manner as in Example 1, and a black film (H-8 film) of Example 8 was produced. The physical properties of the produced black fine particles and black film were evaluated in the same manner as in Example 1. These results are shown in Table 1.

[Example 9]
After mixing 50 g of D1-1 solution, 50 g of D2-1 solution, 3.75 g of comb urethane polymer dispersant and 34 g of methyl ethyl ketone used in Example 1, water and methyl ethyl ketone were evaporated from the mixture using an evaporator. Dry powder (E-9 powder) was obtained.
Next, 29 g of the above E-9 powder and 71 g of propylene glycol monomethyl ether acetate (PGMEA) were mixed and dispersed using a bead mill, and a black material dispersion (F-9 solution, solid content: 25 mass%) Got.
Subsequent steps were performed in the same manner as in Example 1, and a black film (H-9 film) of Example 9 was produced. The physical properties of the produced black fine particles and black film were evaluated in the same manner as in Example 1. These results are shown in Table 1.

[Example 10]
After mixing D1-1 liquid 90g, D2-1 liquid 10g, comb-shaped urethane polymer dispersing agent 3.75g and methyl ethyl ketone 34g used in Example 1, water and methyl ethyl ketone were evaporated from the mixture using an evaporator, Dry powder (E-10 powder) was obtained.

Next, 29 g of the above E-10 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 (F-10 solution, solid content: 25 mass%). Got.
Subsequent steps were carried out in the same manner as in Example 1, and a black film (H-10 film) of Example 10 was produced. The physical properties of the produced black fine particles and black film were evaluated in the same manner as in Example 1. These results are shown in Table 1.

[Example 11]
(Synthesis of substantially rod-shaped particles)
Silver nitrate 56g was melt | dissolved in the pure water, and 1500 g of silver nitrate aqueous solution (A2-11 liquid) was prepared. Moreover, 78 g of trisodium citrate dihydrate was dissolved in pure water to prepare 2500 g of an aqueous solution of trisodium citrate (solution B2-11). Next, the A2-11 solution was dropped into and mixed with the B2-11 solution, and then 500 g of an aqueous solution in which 0.025 g of sodium borohydride was dissolved in pure water was dropped and mixed, and 18 g of ascorbic acid was further added. 500 g of an aqueous solution dissolved in pure water was added dropwise and mixed to obtain a C2-11 solution.

  Subsequently, the above-mentioned C2-11 solution was dropped and mixed in 4000 g of tin fine particle dispersion obtained by mixing 150 g of tin colloid (average particle size: 20 nm, solid content: 10% by mass, manufactured by Sumitomo Osaka Cement Co., Ltd.) and pure water. . Further, an aqueous solution obtained by dissolving 180 g of tartaric acid in 2000 g of pure water was dropped into a mixed liquid of the tin fine particle dispersion and the C3 liquid and stirred to dissolve excess tin colloid. Thereafter, washing was performed by centrifugation to prepare an aqueous dispersion of black fine particles (D2-11 solution, solid content: 25% by mass).

(Preparation of black material dispersion)
Next, 30 g of the D1-1 solution used in Example 1, 70 g of the D2-11 solution, 3.75 g of the comb-shaped urethane polymer dispersant, and 34 g of methyl ethyl ketone were mixed, and then water and methyl ethyl ketone were evaporated from the mixture using an evaporator. And dried powder (E-11 powder) was obtained.
Next, 29 g of the E-11 powder and 71 g of propylene glycol monomethyl ether acetate (PGMEA) were mixed and dispersed using a bead mill, and a black material dispersion (F-11 liquid, solid content: 25 mass%) Got.

(Production of black film)
Subsequent steps were carried out in the same manner as in Example 1, and a black film (H-11 film) of Example 11 was produced. The physical properties of the produced black fine particles and black film were evaluated in the same manner as in Example 1. These results are shown in Table 1.

[Example 12]
After mixing 10 g of the D1-1 solution used in Example 1, 90 g of the D2-11 solution used in Example 11, 3.75 g of the comb-shaped urethane polymer dispersant and 34 g of methyl ethyl ketone, water and water were removed from the mixture using an evaporator. Methyl ethyl ketone was evaporated to obtain a dry powder (E-12 powder).

Next, 29 g of the above E-12 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 (F-12 solution, solid content: 25% by mass). Got.
Subsequent steps were carried out in the same manner as in Example 1, and a black film (H-12 film) of Example 12 was produced. The physical properties of the produced black fine particles and black film were evaluated in the same manner as in Example 1. These results are shown in Table 1.

[Example 13]
(Synthesis of nearly spherical particles)
Silver nitrate 56g was melt | dissolved in the pure water, and 1500 g of silver nitrate aqueous solution (A1-13 liquid) was prepared. In addition, 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 a trisodium citrate aqueous solution (B1-13 solution). Next, the A1-13 solution was dropped into and mixed with the B1-13 solution, and then 500 g of an aqueous solution in which 25 g of sodium borohydride was dissolved in pure water was dropped and mixed to obtain a C1-13 solution. .
Then, it wash | cleaned by centrifugation and prepared the black particle aqueous dispersion (D1-13 liquid, solid content: 25 mass%).

(Synthesis of substantially rod-shaped particles)
Silver nitrate 56g was melt | dissolved in the pure water, and 1500 g of silver nitrate aqueous solution (A2-13 liquid) was prepared. In addition, 78 g of trisodium citrate dihydrate and 60 g of polyvinylpyrrolidone diluted to 1% by mass were dissolved in pure water to prepare 2500 g of a trisodium citrate aqueous solution (B2-13 solution). Next, the A2-13 solution was dropped into and mixed with the B2-13 solution, and then 500 g of an aqueous solution in which 0.1 g of sodium borohydride was dissolved in pure water was dropped and mixed, and 36 g of ascorbic acid was further added. 500 g of an aqueous solution dissolved in pure water was dropped and mixed to obtain a C2-13 solution.
Thereafter, washing was performed by centrifugation to prepare an aqueous dispersion of black fine particles (D2-13 solution, solid content: 25% by mass).

(Preparation of black material dispersion and black film)
Next, dry powder (E-13 powder) and black material dispersion were the same as in Example 1 except that 30 g of the D1-13 solution and 70 g of the D2-13 solution were used as the aqueous dispersion of black fine particles. A liquid (F-13 liquid, solid content: 25% by mass) was obtained.
Further, in the same manner as in Example 1, a black film (H-13 film) of Example 13 was produced from the F-13 solution. The physical properties of the produced black fine particles and black film were evaluated in the same manner as in Example 1. These results are shown in Table 1.

[Example 14]
17 g of D1-1 liquid, 38 g of D2-1 liquid used in Example 1, 112 g of tin colloid (average particle size: 20 nm, solid content: 10% by mass, manufactured by Sumitomo Osaka Cement Co., Ltd.), comb-shaped urethane polymer dispersant 3 After mixing .75 g and methyl ethyl ketone 34 g, water and methyl ethyl ketone were evaporated from the mixture using an evaporator to obtain a dry powder (E-14 powder).
Next, 29 g of the E-14 powder and 71 g of propylene glycol monomethyl ether acetate (PGMEA) were mixed and dispersed using a bead mill, and a black material dispersion (F-14 liquid, solid content: 25% by mass) Got.
Subsequent steps were carried out in the same manner as in Example 1, and a black film (H-14 film) of Example 14 was produced. The physical properties of the produced black fine particles and black film were evaluated in the same manner as in Example 1. These results are shown in Table 1.

[Example 15]
(Synthesis of substantially plate-like particles)
Silver nitrate 56g was melt | dissolved in the pure water, and 1500 g of silver nitrate aqueous solution (A2-15 liquid) was prepared. In addition, 39 g of trisodium citrate dihydrate and 60 g of polyvinylpyrrolidone diluted to 1% by mass were dissolved in pure water to prepare 2500 g of a trisodium citrate aqueous solution (B2-15 solution). Next, 3600 g of n-hexadecyltrimethylammonium bromide was dissolved in 40 ° C. pure water and added to the B2-15 solution. Next, A2-15 solution was dropped into and mixed with B2-15 solution to which n-hexadecyltrimethylammonium bromide was added, and 500 g of an aqueous solution in which 0.1 g of sodium borohydride was dissolved in pure water was then added. Dropped and mixed, 500 g of an aqueous solution prepared by dissolving 18 g of ascorbic acid in pure water was dropped and mixed to obtain a C2-15 solution.

  Subsequently, the above-mentioned C2-15 solution was dropped and mixed in 4000 g of tin fine particle dispersion obtained by mixing 150 g of tin colloid (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 C2-15 liquid and stirred to dissolve excess tin colloid. Then, it wash | cleaned by centrifugation and prepared the black particle aqueous dispersion (D2-15 liquid, solid content: 25 mass%).

(Preparation of black material dispersion and black film)
Next, dry powder (E-15 powder) was used in the same manner as in Example 1 except that 30 g of D1-1 solution used in Example 1 and 70 g of D2-15 solution were used as the aqueous dispersion of black fine particles. ) And a black material dispersion (F-15 solution, solid content: 25% by mass).
Further, in the same manner as in Example 1, a black film (H-15 film) of Example 15 was produced from the F-15 solution. The physical properties of the produced black fine particles and black film were evaluated in the same manner as in Example 1.
When the cross section of the black film was observed, substantially spherical particles and substantially plate-like particles (triangular plate-like particles) were mixed. These results are shown in Table 1.

[Example 16]
After mixing D1-1 solution 30g, D2-1 solution 70g, comb-shaped urethane polymer dispersant 1.88g and methyl ethyl ketone 17g used in Example 1, water and methyl ethyl ketone were evaporated from the mixture using an evaporator, Dry powder (E-16 powder) was obtained.
Next, 29 g of the E-16 powder and 71 g of propylene glycol monomethyl ether acetate (PGMEA) were mixed and dispersed using a bead mill, and a black material dispersion (F-16 solution, solid content: 25 mass%) Got.
Subsequent steps were performed in the same manner as in Example 1, and a black film (H-16 film) of Example 16 was produced. The physical properties of the produced black fine particles and black film were evaluated in the same manner as in Example 1. These results are shown in Table 1.

[Comparative Example 1]
After mixing 100 g of the D1-13 solution used in Example 13, 3.75 g of the comb-shaped urethane polymer dispersant and 34 g of methyl ethyl ketone, water and methyl ethyl ketone were evaporated from the mixture using an evaporator to obtain dry powder (E-21 Powder).
Next, 29 g of the above E-21 powder and 71 g of propylene glycol monomethyl ether acetate (PGMEA) were mixed and dispersed using a bead mill, and a black material dispersion (F-21 liquid, solid content: 25 mass%) Got.
Subsequent steps were carried out in the same manner as in Example 1, and a black film (H-21 film) of Comparative Example 1 was produced. The physical properties of the produced black fine particles and black film were evaluated in the same manner as in Example 1. These results are shown in Table 1.

[Comparative Example 2]
After mixing 100 g of the D1-1 solution used in Example 1, 3.75 g of the comb-shaped urethane polymer dispersant and 34 g of methyl ethyl ketone, water and methyl ethyl ketone were evaporated from the mixture using an evaporator to obtain dry powder (E-22 Powder).
Next, 29 g of the E-22 powder and 71 g of propylene glycol monomethyl ether acetate (PGMEA) were mixed and dispersed using a bead mill, and a black material dispersion (F-22 liquid, solid content: 25% by mass) Got.
Subsequent steps were performed in the same manner as in Example 1, and a black film (H-22 film) of Comparative Example 2 was produced. The physical properties of the produced black fine particles and black film were evaluated in the same manner as in Example 1. These results are shown in Table 1.

[Comparative Example 3]
30 g of carbon black (Nipex 35, manufactured by Degussa), 3 g of urethane-based dispersant, 67 g of propylene glycol monomethyl ether acetate (PGMEA) are mixed, and then dispersed using a bead mill, and the black fine particle dispersion F-23 (solid content: 30% by mass) was obtained.
Subsequent steps were performed in the same manner as in Example 1 to produce a black film (H-23 film) of Comparative Example 3. The physical properties of the prepared black fine particle dispersion and black film were evaluated in the same manner as in Example 1. These results are shown in Table 1.

[Comparative Example 4]
30 g of titanium black (13M-T, manufactured by Gemco), 6.67 g of urethane-based dispersant, 63.33 g of propylene glycol monomethyl ether acetate (PGMEA) are mixed, and then dispersed using a bead mill, and black fine particle dispersion F-24 A liquid (solid content: 30% by mass) was obtained.
Subsequent steps were performed in the same manner as in Example 1, and a black film (H-24 film) of Comparative Example 4 was produced. The physical properties of the prepared black fine particle dispersion and black film were evaluated in the same manner as in Example 1. These results are shown in Table 1.

Claims (8)

Containing metal fine particles having an average primary particle diameter of 1 nm or more and 300 nm or less,
The metal fine particles in the film are either a mixture of substantially spherical particles and substantially rod-like particles, a mixture of substantially spherical particles and substantially plate-like particles, or a mixture of substantially spherical particles, substantially rod-like particles and substantially plate-like particles. A visible near-infrared shielding black film characterized by being.   2. The visible near infrared ray according to claim 1, wherein an average primary particle diameter of the substantially spherical particles is 1 nm or more and 100 nm or less, and an average primary particle diameter of the substantially rod-like particles or substantially plate-like particles is 5 nm or more and 300 nm or less. Shielding black film.   Any or all of the substantially spherical particles, substantially rod-like particles, and substantially plate-like particles are aggregated particles of the metal fine particles, and the average dispersed particle diameter in the film of the substantially spherical particles is 1 nm or more and 100 nm or less, The visible near-infrared shielding black film according to claim 1, wherein an average dispersed particle diameter in the film of the substantially rod-like particles or the substantially plate-like particles is 5 nm or more and 300 nm or less.   The metal fine particles are selected from the group consisting of platinum, gold, silver, copper, palladium, nickel, tin, cobalt, rhodium, iridium, iron, ruthenium, osmium, manganese, molybdenum, tungsten, niobium, tantalum, titanium, and bismuth. The visible near-infrared light shielding black film of any one of Claims 1-3 containing 1 type, or 2 or more types.   The optical density at a wavelength of 400 nm to 1300 nm in the visible near-infrared shielding black film is 1.0 or more, an optical density at a wavelength of 555 nm is 1.0 or more, and an optical density at a wavelength of 1300 nm is 0.6 or more. Item 5. The visible and near infrared shielding black film according to any one of Items 1 to 4. The visible near-infrared light shielding black film according to claim 1, which has a volume resistivity of 10 ¹¹ Ω · cm or more.   The base material with a visible near-infrared light shielding black film in which the visible near-infrared light shielding black film of any one of Claims 1-6 was formed.   The solid-state image sensor which has a base material with the visible near-infrared light shielding black film of any one of Claims 1-6, or the visible near-infrared light shielding black film of Claim 7.