JP5828731B2 - Dispersion and heat shield - Google Patents

Description

  The present invention relates to a dispersion and a heat ray shielding material.

  In recent years, heat ray shielding materials for automobiles and building windows have been developed as one of energy saving measures for reducing carbon dioxide. From the viewpoint of the heat ray shielding property (acquisition rate of solar heat), the heat ray reflection type without re-radiation is better than the heat ray absorption type with re-radiation of absorbed light into the room (about 1/3 of the absorbed solar energy). Various proposals have been made.

  As such a heat ray shielding material, in Patent Documents 1 and 2, a dispersion containing silver tabular grains having a specific shape is coated on a support, and the silver tabular grains are oriented at a specific inclination angle, thereby reflecting A heat ray shielding material having high wavelength selectivity and reflection band selectivity and excellent visible light transmission and radio wave transmission has been disclosed. In Patent Documents 1 and 2, a dispersion of silver tabular grains is prepared using gelatin as a dispersion medium.

  Patent Document 3 describes an infrared shielding filter using a dispersion in which silver-containing flat metal fine particles are dispersed using a dispersion polymer having at least one sulfur atom and / or nitrogen atom. Has been.

US2011 / 0111210A1 gazette JP 2011-118347 A JP 2007-178915 A JP 2006-291347 A JP 2003-287834 A

  However, Patent Documents 1 to 3 have not studied the stability of the dispersion. Here, when a dispersion is used for the heat ray shielding material, it is necessary for the surface orientation without aggregation of the tabular metal particles to improve the quality stability, and also reduce the disposal loss and improve the manufacturing cost. From the viewpoint, the long-term stability of the dispersion is required. Then, when this inventor examined the long-term stability for 1 week about the dispersion of patent document 1 and 2, it turned out that dissatisfaction remains.

As a method for improving the stability of the dispersion, Patent Document 4 describes a dispersion in which silver particles having a specific particle size are encapsulated with a compound having a mercapto group, and is excellent in dispersibility and stability. It is disclosed. However, in the same document, dispersibility and stability have not been studied in the case where the conditions necessary for use as a heat ray shielding material in which the metal particles are flat are satisfied. Moreover, in patent document 4, the evaluation result for 3 days was only disclosed by the Example of the literature also in the first place also about stability of the dispersion.
Further, Patent Document 5 describes a problem that a silver halide salt has a problem of aggregation as the aspect ratio of tabular grains is increased. On the other hand, this document describes a method in which grain aggregation is prevented and a tabular silver halide emulsion can be produced stably by using a polymer having a mercapto group. However, no study was made on the application of metal (zero-valent) silver.

As described above, the dispersion is excellent in long-term stability for 1 week, maintains good dispersibility after long-term storage, and can exhibit excellent heat ray shielding performance even using a dispersion after long-term storage, Development of technology for improving the stability of the dispersion has been desired.
An object of the present invention is to solve the above-described problems. That is, the problem to be solved by the present invention is to provide a dispersion that can form a heat ray shielding material having good dispersion stability over a long period of time and having excellent heat ray shielding performance even after long-term storage. .

  As a result of intensive studies by the inventor of the present invention to solve the above-mentioned problems, the gelatin primary dispersion of metal tabular grains described in Patent Documents 1 and 2 is purified (desalted and degelatinized) to obtain a tabular metal. By forming a secondary dispersion in which particles are dispersed in a dispersion containing a compound having a specific structure, the long-term stability of the dispersion is improved, and a heat-ray shielding material having excellent heat-ray shielding performance after long-term storage is formed. I found out that I could do it.

This invention is based on the said knowledge by this inventor, As means for solving the said subject, it is as follows.
[1] A compound having a metal tabular grain and at least one compound having a nitrogen-containing aromatic ring structure having a mercapto group, and the metal tabular grain having a nitrogen-containing aromatic ring structure having at least the mercapto group. Dispersion characterized by being dispersed in a dispersion medium containing.
[2] In the dispersion described in [1], the metal tabular grains are preferably tabular grains having a substantially hexagonal shape to a substantially disc shape.
[3] The dispersion according to [2] preferably has an average particle diameter of 70 nm to 500 nm of the substantially hexagonal to substantially disc shaped metal tabular grains.
[4] The dispersion according to [2] or [3] preferably has an aspect ratio (average particle diameter / average particle thickness) of the substantially hexagonal to substantially disk-shaped metal tabular grains of 8 to 40. .
[5] In the dispersion according to any one of [1] to [4], the compound having a nitrogen-containing aromatic ring structure having a mercapto group is preferably water-soluble.
[6] In the dispersion according to any one of [1] to [5], the compound having a nitrogen-containing aromatic ring structure having a mercapto group has a nitrogen-containing aromatic ring structure having a mercapto group. A polymer having a chain or a terminal group is preferable.
[7] In the dispersion according to any one of [1] to [6], the nitrogen-containing aromatic ring structure having a mercapto group is preferably a mercaptotetrazole group or a mercaptotriazole group.
[8] In the dispersion according to any one of [1] to [7], the metal tabular grain preferably contains at least silver.
[9] A heat ray shielding material comprising a metal particle-containing layer obtained by applying the dispersion according to any one of [1] to [8] on a substrate.

  According to the present invention, it is possible to provide a dispersion capable of forming a heat ray shielding material having good dispersion stability over a long period of time and having excellent heat ray shielding performance even after long-term storage.

FIG. 1A is a schematic perspective view showing an example of the shape of a tabular grain contained in the heat ray shielding material of the present invention, and shows a substantially disc-shaped tabular grain. FIG. 1B is a schematic perspective view showing an example of the shape of a tabular grain contained in the heat ray shielding material of the present invention, and shows a substantially hexagonal tabular grain. FIG. 2A is a schematic cross-sectional view showing an example of the existence state of a metal particle-containing layer containing metal tabular grains in the heat ray shielding material of the present invention. FIG. 2B is a schematic cross-sectional view showing the existence state of a metal particle-containing layer containing metal tabular grains in the heat ray shielding material of the present invention, and a metal particle-containing layer containing metal tabular grains (parallel to the plane of the substrate). ) And an angle (θ) between the plane of the substantially hexagonal to disk-shaped metal tabular grains. FIG. 2C is a schematic cross-sectional view showing the existence state of the metal particle-containing layer containing the metal tabular grains in the heat ray shielding material of the present invention, wherein the metal tabular grains in the depth direction of the heat ray shielding material of the metal particle-containing layer FIG. FIG. 3 is a schematic cross-sectional view showing another example of the existence state of the metal particle-containing layer containing metal tabular grains in the heat ray shielding material of the present invention. FIG. 4 is a schematic cross-sectional view showing another example of the presence state of the metal particle-containing layer containing metal tabular grains in the heat ray shielding material of the present invention.

Hereinafter, the dispersion and heat ray shielding material of the present invention will be described in detail.
The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

[Dispersion]
The dispersion of the present invention contains metal tabular grains and at least one compound having a nitrogen-containing aromatic ring structure having a mercapto group, and the metal tabular grains have at least the mercapto group-containing nitrogen-containing aromatic ring structure. It is characterized by being dispersed in a dispersion medium containing a compound having

-Metallic tabular grains-
The dispersion of the present invention contains tabular metal grains, and the tabular metal grains are dispersed in a dispersion medium containing at least a compound having a nitrogen-containing aromatic ring structure having the mercapto group.
Hereinafter, the metal tabular grains and the dispersion medium will be described.

-Material-
The material of the metal tabular grain is not particularly limited and may be appropriately selected depending on the purpose. From the viewpoint of high heat ray (near infrared) reflectance, for example, silver, gold, aluminum, copper, rhodium, Nickel, platinum and the like are suitable, and silver is more preferred.

  The metal in the present invention is a ratio of a metal element in a composition formula among a compound formed by bonding a metal element alone or two or more metal elements, or a compound formed by bonding a metal element and a non-metal element. (Molar ratio) is a compound having 60% or more. The proportion of metal elements is preferably 75% or more, more preferably 90% or more. However, the vicinity of the particle surface where the composition changes due to oxidation or the like is not limited thereto. The metal element is an element located on the left side of an oblique line connecting boron, silicon, arsenic, tellurium, and astatine in the periodic table of elements.

--- Shape--
The metal tabular grain is not particularly limited as long as it is a grain composed of two main planes (see FIGS. 1A and 1B), and can be appropriately selected according to the purpose. And a substantially triangular shape. Among these, from the viewpoint of high visible light transmittance, a polygonal shape of approximately hexagonal shape or more to a substantially disc shape is more preferable, and a substantially hexagonal shape or a substantially disc shape is particularly preferable.
In the present specification, the substantially disk shape means that the number of sides having a length of 50% or more of the average equivalent circle diameter is ignored when the unevenness of 10% or less of the average equivalent circle diameter of the metal tabular grain described later is ignored. The shape which is 0 per one tabular grain of metal. The substantially disk shape is not particularly limited as long as it has no corners and round shape when the metal tabular grains are observed from above the main plane with a transmission electron microscope (TEM), and is appropriately selected according to the purpose. be able to. The “side” of a tabular metal grain refers to a straight line portion when the tabular metal grain is observed from above the main plane. In particular, when the corner of the tabular metal grain is dull, a straight line excluding a curved portion near the corner. Say the part.
In the present specification, the substantially hexagonal shape means that the number of sides having a length of 20% or more of the average equivalent circle diameter is ignored when unevenness of 10% or less of the average equivalent circle diameter of the metal tabular grain described later is ignored. This refers to the shape of 6 tabular grains per metal tabular grain. The same applies to other polygons. The substantially hexagonal shape is not particularly limited as long as it is a substantially hexagonal shape when the metal tabular grains are observed from above the main plane with a transmission electron microscope (TEM), and can be appropriately selected according to the purpose. For example, the hexagonal corners may be sharp or dull, but the corners are preferably dull in that the absorption in the visible light region can be reduced. There is no restriction | limiting in particular as a grade of the dullness of an angle, According to the objective, it can select suitably.

  Of the metal particles present in the dispersion of the present invention, the approximately hexagonal to approximately disc-shaped metal tabular particles are preferably 60% by number or more, and 65% by number or more based on the total number of metal particles. Is more preferable, and 70% by number or more is more preferable. When the ratio of the substantially hexagonal to substantially disk-shaped metal tabular grains is 60% by number or more, the visible light transmittance is preferably increased.

--Average particle diameter (average equivalent circle diameter) and particle size distribution of particle diameter (equivalent circle diameter)-
There is no restriction | limiting in particular as an average particle diameter (average circle equivalent diameter) of the said metal tabular grain, Although it can select suitably according to the objective, 70 nm-500 nm are preferable, and 100 nm-400 nm are more preferable. When the average particle diameter (average equivalent circle diameter) is less than 70 nm, the contribution of absorption of the metal tabular grains becomes larger than the reflection, so that sufficient heat ray reflectivity may not be obtained. (Scattering) may increase, and the transparency of the substrate may be impaired.
Here, the average particle diameter (average equivalent circle diameter) is a value obtained by measuring the particle diameter (equivalent circle diameter) of primary particles using a microscope as the projected area equivalent circle diameter defined in JIS Z 8901. Mean value of In the present specification, specifically, it means an average value of main plane diameters (maximum lengths) of 200 tabular grains arbitrarily selected from images obtained by observing grains with a TEM.
Two or more kinds of metal particles having different average particle diameters (average circle equivalent diameters) can be contained in the metal particle-containing layer. In this case, the peak of the average particle diameter (average circle equivalent diameter) of the metal particles is 2 It may have two or more, that is, two or more average particle diameters (average circle equivalent diameter).

In the dispersion of the present invention, the coefficient of variation in the particle size distribution of the metal tabular grains is preferably 30% or less, and more preferably 10% or less. When the coefficient of variation exceeds 30%, the reflection wavelength region of the heat ray in the heat ray shielding material may become broad.
Here, the coefficient of variation in the particle size distribution of the tabular metal grains is obtained, for example, by obtaining the standard deviation of the particle size distribution of 200 metal tabular grains used for calculating the average value obtained as described above, and obtaining the main plane as described above. It is the value (%) divided by the average value (average particle diameter (average equivalent circle diameter)) of the diameter (maximum length).

--Aspect ratio--
The aspect ratio of the metal tabular grain is not particularly limited and may be appropriately selected depending on the intended purpose. However, the heat ray shielding material formed using the dispersion according to the present invention has a near red color from the visible light region long wavelength side. From the viewpoint of increasing the reflectance in the outside light region, it is preferably 2 to 80, more preferably 4 to 60, and particularly preferably 8 to 40. When the aspect ratio is less than 2, the reflection wavelength becomes smaller than 500 nm, and when it exceeds 80, the reflection wavelength becomes longer than 2,000 nm and sufficient heat ray reflectivity may not be obtained.
The aspect ratio means a value obtained by dividing the average particle diameter (average circle equivalent diameter) of the tabular metal grains by the average grain thickness of the tabular metal grains. The average grain thickness corresponds to the distance between the main planes of the metal tabular grain, and is, for example, as shown in FIGS. 1A and 1B and can be measured by an atomic force microscope (AFM).
The method for measuring the average particle thickness by the AFM is not particularly limited and can be appropriately selected depending on the purpose.For example, a particle dispersion containing metal tabular particles is dropped onto a glass substrate and dried. For example, a method of measuring the thickness of one particle may be used.

--Method of synthesizing tabular metal grains--
The method for synthesizing the metal tabular grains is not particularly limited as long as it can synthesize a substantially hexagonal shape to a substantially disc shape, and can be appropriately selected according to the purpose. For example, a chemical reduction method, a photochemical reduction method, or the like. And a liquid phase method such as an electrochemical reduction method. Among these, a liquid phase method such as a chemical reduction method or a photochemical reduction method is particularly preferable in terms of shape and size controllability. After synthesizing hexagonal or triangular tabular metal grains, for example, etching treatment with a dissolved species that dissolves silver such as nitric acid or sodium sulfite, or aging treatment by heating, hexagonal or triangular shaped metal tabular grains The tabular shape may be obtained by dulling the corners to obtain approximately hexagonal to substantially disc-shaped metal tabular grains.

  As a method for synthesizing the metal tabular grains, in addition to the above, a seed crystal may be previously fixed on the surface of a transparent substrate such as a film or glass, and then metal grains (for example, Ag) may be grown in a tabular form.

  In the dispersion of the present invention, the metal tabular grains may be subjected to further treatment in order to impart desired properties. The further treatment is not particularly limited and may be appropriately selected depending on the purpose. For example, the formation of a high refractive index shell layer, the addition of various additives such as a dispersant and an antioxidant may be included. Can be mentioned.

-Dispersion medium-
The dispersion of the present invention is characterized in that the metal tabular grains are dispersed in a dispersion medium containing at least a compound having a nitrogen-containing aromatic ring structure having the mercapto group.
The stage of adding the dispersion medium is not particularly limited, and may be added when preparing the metal tabular grains, and the metal tabular grains may be prepared in the presence of the dispersion medium. In addition, after adjusting the metal tabular grains, the dispersion medium may be added to control the dispersion state.
The dispersion medium may be a low molecular compound or a polymer.
Hereinafter, a dispersion medium that is preferably added before preparing the metal tabular grains and a dispersion medium that is preferably added after adjustment for adjusting the dispersion state will be described.

-Dispersion medium preferably added when preparing metal tabular grains-
As a dispersion medium that is preferably added when preparing the metal tabular grains, the following dispersion polymers are preferable. The state of presence of the tabular metal grains at the time of dispersion is not particularly limited, but the tabular metal grains are preferably present in a stable dispersed state, for example, more preferably in a colloidal state.
The step of adding the dispersion polymer is preferably performed before the metal tabular grains are prepared, and the metal tabular grains are prepared in the presence of the dispersion polymer.
In addition, as long as it does not contradict the meaning of this invention, after adjusting the said metal tabular grain, you may add the said dispersion polymer for control of a dispersed state.

  Examples of the dispersion polymer include thiol group-containing compounds, amino acids or derivatives thereof, peptide compounds, polysaccharides and natural polymers derived from polysaccharides, synthetic polymers, and polymers such as gels derived therefrom. Can be used as an agent.

Examples of the polymers include gelatin, polyvinyl alcohol, methyl cellulose, hydroxypropyl cellulose, polyalkyleneamine, partial alkyl esters of polyacrylic acid, polyvinyl pyrrolidone, and polyvinyl pyrrolidone copolymers, which are protective colloidal polymers. It is done.
For the dispersion polymer that can be used as the dispersant, for example, the description of “Encyclopedia of Pigments” (edited by Seijiro Ito, published by Asakura Shoin Co., Ltd., 2000) can be referred to.

  In addition to the above, as the dispersion polymer, a polymer having a carboxylic acid group in the side chain, for example, JP-B-59-44615, JP-B-54-34327, JP-B-58-12777, JP-B-54-25957 Methacrylic acid copolymer, acrylic acid copolymer, itaconic acid copolymer, crotonic acid copolymer, maleic acid described in JP-A No. 59-53836 and JP-A No. 59-71048 Examples thereof include a copolymer and a partially esterified maleic acid copolymer. Moreover, the cellulose derivative which has a carboxylic acid group in a side chain can also be mentioned. In addition, those obtained by adding a cyclic acid anhydride to a polymer having a hydroxyl group can be preferably used. In particular, a copolymer of benzyl (meth) acrylate and (meth) acrylic acid or a multicomponent copolymer of benzyl (meth) acrylate, (meth) acrylic acid and other monomers described in US Pat. No. 4,139,391 is also available. Can be mentioned.

  Among the dispersed polymers, gelatin is preferable, and high molecular weight gelatin (number average molecular weight of 150,000 or more) is more preferable.

The dispersion medium preferably added when preparing the metal tabular grains may or may not be included as the dispersion medium in the dispersion of the present invention. Further, when the dispersion medium that is preferably added when preparing the metal tabular grains is contained in the dispersion of the present invention, the dispersion medium contains different properties from those when preparing the metal tabular grains. It may be. Moreover, the dispersion medium that is preferably added when preparing the metal tabular grains may be replaced with the dispersion medium that is preferably added after preparing the metal tabular grains described later, and may be an aspect that is hardly contained.
In addition, unless it is contrary to the meaning of this invention, you may add the dispersion medium added preferably, after preparing the metal tabular grain mentioned later, when preparing the said metal tabular grain.

-Dispersion medium preferably added after preparing metal tabular grains-
Examples of the dispersion medium that is preferably added after preparing the metal tabular grains include compounds having a nitrogen-containing aromatic ring structure having the mercapto group. It is preferable from the viewpoint of long-term stability that the dispersion medium that is preferably added after preparing the metal tabular grains is sufficiently left in the dispersion of the present invention.

(Compound having a nitrogen-containing aromatic ring structure having a mercapto group)
The compound having a nitrogen-containing aromatic ring structure having a mercapto group is not particularly limited, and may be water-soluble or hardly soluble. Further, the compound having a nitrogen-containing aromatic ring structure having a mercapto group may be a low molecular compound or a polymer.
In the dispersion of the present invention, the nitrogen-containing aromatic ring structure having a mercapto group is preferably a mercaptotetrazole group or a mercaptotriazole group.
Hereinafter, preferred structures of the compound having a nitrogen-containing aromatic ring structure having a mercapto group will be described.

(1) Water-soluble mercapto compound In the dispersion of the present invention, the compound having a nitrogen-containing aromatic ring structure having a mercapto group is preferably water-soluble.
Among these, at least one water-soluble mercaptotetrazole compound or water-soluble mercaptotriazole compound represented by the following general formula (I-1) or the following general formula (I-2) is preferable.

Formula (I-1)

In the general formula (I-1), R ⁵ represents an organic residue substituted with at least one selected from the group consisting of —SO ₃ M, —COOM, —OH and —NHR ² , and M represents a hydrogen atom. Represents an alkali metal atom, a quaternary ammonium group or a quaternary phosphonium group, and R ² represents a hydrogen atom, alkyl having 1 to 6 carbon atoms, —COR ³ , —COOR ³ or —SO ₂ R ³ . R ³ represents a hydrogen atom, alkyl, or aryl.

Formula (I-2)

In the general formula (I-2), R ⁶ represents a hydrogen atom, substituted or unsubstituted alkyl, or substituted or unsubstituted aryl, and R ⁵ represents —SO ₃ M, —COOM, —OH, and —NHR ^2. Represents an organic residue substituted with at least one selected from the group consisting of: M represents a hydrogen atom, an alkali metal atom, a quaternary ammonium group or a quaternary phosphonium group; R ² represents a hydrogen atom; Represents an alkyl of ˜6, —COR ³ , —COOR ³ or —SO ₂ R ³ . R ³ represents a hydrogen atom, alkyl, or aryl.

  First, the water-soluble mercaptotetrazole compound represented by the general formula (I-1) will be described.

In the general formula (I-1), R ⁵ is an organic residue substituted with at least one selected from the group consisting of —SO ₃ M, —COOM, —OH and —NHR ² , specifically An alkyl group having 1 to 10 carbon atoms (for example, methyl, ethyl, propyl, hexyl, cyclohexyl) and an aryl group having 6 to 14 carbon atoms (for example, phenyl, naphthyl) are shown.

Each group represented by R ⁵ in formula (I-1) may be further substituted, and examples of the substituent include the following. Halogen atoms (fluorine, chlorine, bromine, iodine), cyano, nitro, ammonio (eg, trimethylammonio), phosphonio, sulfo (including salt), sulfino (including salt), carboxy (including salt), phosphono ( Salt), hydroxy, mercapto, hydrazino, alkyl (eg, methyl, ethyl, n-propyl, isopropyl, t-butyl, n-octyl, cyclopentyl, cyclohexyl), alkenyl (eg, allyl, 2-butenyl, 3-pentenyl), alkynyl (eg, propargyl, 3-pentynyl), aralkyl (eg, benzyl, phenethyl), aryl (eg, phenyl, naphthyl, 4-methylphenyl), heterocycle (eg, pyridyl, furyl, imidazolyl, Piperidyl, morpholino), alkoxy For example, methoxy, ethoxy, butyloxy), aryloxy (eg, phenoxy, 2-naphthyloxy), alkylthio (eg, methylthio, ethylthio), arylthio (eg, phenylthio), amino (eg, unsubstituted amino, methylamino, Dimethylamino, ethylamino, alinino), acyl (eg acetyl, benzoyl, formyl, pivaloyl), alkoxycarbonyl (eg methoxycarbonyl, ethoxycarbonyl), aryloxycarbonyl (eg phenoxycarbonyl), carbamoyl (eg unsubstituted) Carbamoyl, N, N-dimethylcarbamoyl, N-ethylcarbamoyl, N-phenylcarbamoyl), acyloxy (eg acetoxy, benzoyloxy), acylamino (eg Acetylamino, benzoylamino), alkoxycarbonylamino (eg, methoxycarbonylamino), aryloxycarbonylamino (eg, phenoxycarbonylamino), ureido (eg, unsubstituted ureido, N-methylureido, N-phenylureido) ), Alkylsulfonylamino (eg methylsulfonylamino), arylsulfonylamino (eg phenylsulfonylamino), alkylsulfonyloxy (eg methylsulfonyloxy), arylsulfonyloxy (eg phenylsulfonyloxy), alkylsulfonyl (eg , Mesyl), arylsulfonyl (eg tosyl), alkoxysulfonyl (eg methoxysulfonyl), aryloxysulfonyl (eg pheno) Xylsulfonyl), sulfamoyl (eg, unsubstituted sulfamoyl, N-methylsulfamoyl, N, N-dimethylsulfamoyl, N-phenylsulfamoyl), alkylsulfinyl (eg, methylsulfinyl), arylsulfinyl (eg, , Phenylsulfinyl), alkoxysulfinyl (eg, methoxysulfinyl), aryloxysulfinyl (eg, phenoxysulfinyl), phosphoric acid amide (eg, N, N-diethylphosphoric acid amide) and the like. These groups may be further substituted. Moreover, when there are two or more substituents, they may be the same or different.

Here, when there are two or more substituents —SO ₃ M, —COOM, —OH and —NHR ² of R ⁵ , they may be the same or different.

In General Formula (I-1), R ² represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, —COR ³ , —CO ₂ R ³ , or —SO ₂ R ³ , wherein R ³ is a hydrogen atom, An alkyl group having 1 to 20 carbon atoms (for example, methyl, ethyl, propyl, hexyl, cyclohexyl, dodecyl, octadecyl) and aryl (for example, phenyl, naphthyl) are represented. These groups may be substituted by the substituents exemplified as the substituent for R ⁵ .

  In general formula (I-1), M is a hydrogen atom, an alkali metal atom (for example, lithium, sodium, potassium, etc.), quaternary ammonium (for example, ammonio, tetramethylammonio, benzyltrimethylammonio, tetrabutylammonio, etc.). ) Or a quaternary phosphonium (for example, tetramethylphosphonio and the like).

In general formula (I-1), preferably, R ⁵ is phenyl substituted with —SO ₃ M, phenyl substituted with —COOM, phenyl substituted with —NHR ² , and carbon number of 1 substituted with —SO ₃ M. 4 alkyl, alkyl having 1 to 4 carbon atoms substituted by —COOM, R ² is hydrogen atom, alkyl having 1 to 4 carbon atoms, —COR ³ , R ³ is hydrogen atom, hydrophilic group (for example, C 1 -C 4 alkyl substituted by (carboxyl, sulfo, hydroxy), and M is a hydrogen atom or a sodium atom. More preferably, R ⁵ is phenyl substituted with —SO ₃ M and phenyl substituted with —COOM. Specific examples of the compound represented by formula (I-1) are shown below, but the present invention is not limited thereto.

  Next, the mercaptotriazole compound of the general formula (I-2) will be described.

M of formula (I-2), and R ⁵ is M in the general formula (I-1), and with R ⁵ synonymous.

In the general formula (I-2), R ⁶ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms (eg, methyl, ethyl, propyl, hexyl, cyclohexyl, etc.), aryl having 6 to 15 carbon atoms (eg, phenyl, Naphthyl and the like, and alkyl or aryl may be substituted with the substituents listed as the substituent for R ^{5 in} formula (I-1).

In general formula (I-2), R ⁶ is preferably a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or phenyl, and R ⁵ is phenyl substituted with —SO ₃ M, phenyl substituted with —COOM, phenyl -NHR ² is substituted, -SO ₃ M is alkyl having 1 to 4 carbon atoms substituted, -COOM is alkyl having 1 to 4 carbon atoms which is substituted, R ² is a hydrogen atom, from 1 to 4 carbon atoms Alkyl, —COR ³ , R ³ is a hydrogen atom, alkyl having 1 to 4 carbon atoms substituted by a hydrophilic group (for example, carboxyl, sulfo, hydroxy), and M is a hydrogen atom or a sodium atom. More preferably, R ⁶ is a hydrogen atom, R ⁵ is phenyl substituted with —SO ₃ M, and phenyl substituted with —COOM.

  Specific examples of the compound represented by formula (I-2) are shown below, but the present invention is not limited thereto.

  The compound represented by the general formula (I-1) or the general formula (I-2) is known and can be synthesized by the methods described in the following documents. John A. Montgomery, "The Chemistry of Heterocyclic Chemistry", 1,2,4-triazole ("The Chemistry of Heterocyclic Chemistry" 1,2,4-triazole), JOHN WILEY & Co. 1981), 404-442, S.E. R. Sandler, W.M. Karo, “Organic Functional Group Preparation” Academic Press (1968), pages 312 to 315, Kevin T. et al. Edited by Pott, “Comprehensive Heterocyclic Compounds” (“COMPREHENSIVE HETEROCYCLIC COMPUNDS”), PERGAMON PRESS, Vol. 5, pp. 761-784, pp. 825-834, Robert C. Edited by Elderfield, “Heterocyclic Compounds” (“HETEROCYCLIC COMPOUNDS”), JOHN WILEY & SONS (1961), pages 425-445, Frederic R. Benson, “The High Nitrogen COMPOUNDS”, JOHN WILEY & SONS (1984), 640-653.

(2) Polymer having a nitrogen-containing aromatic ring having a mercapto group as a partial structure The dispersion of the present invention is such that the compound having a nitrogen-containing aromatic ring structure having a mercapto group is a nitrogen-containing aromatic ring having a mercapto group. A polymer having a structure in a side chain or a terminal group is preferable. The polymer having a nitrogen-containing aromatic ring having a mercapto group as a partial structure contains a mercapto group represented by the following general formula (1).
General formula (1)
Z-SH

  In the general formula (1), the nitrogen-containing aromatic ring represented by Z is specifically a monocyclic or condensed nitrogen-containing aromatic heterocycle, preferably a 5- to 7-membered nitrogen-containing aromatic. A heterocyclic ring, more preferably a 5- or 6-membered nitrogen-containing aromatic heterocyclic ring. Specifically, imidazole, pyrazole, triazole, tetrazole, thiazole, oxazole, selenazole, benztriazole, benzthiazole, benzoxazole, benzselenazole, thiadiazole, oxadiazole, naphthothiazole, naphthoxazole, azabenzimidazole, purine, Examples include pyridine, pyrazine, pyrimidine, pyridazine, triazine, triazaindene, tetrazaindene and the like. More preferably, it is a 5-membered nitrogen-containing aromatic heterocycle, and specific examples include imidazole, pyrazole, triazole, tetrazole, thiazole, oxazole, benztriazole, benzthiazole, benzoxazole, thiadiazole, and oxadiazole. Particularly preferred are triazole and tetrazole, and most preferred is tetrazole.

  The mercapto group-containing polymer is preferably a water-soluble polymer. In the present specification, the “water-soluble polymer” refers to a polymer that dissolves in water by 0.5 mass% or more, preferably a polymer that dissolves by 1.0 mass% or more, more preferably 2.0 mass%. A polymer that dissolves by mass% or more, more preferably a polymer that dissolves 4.0 mass% or more.

The mercapto group-containing polymer preferably contains, on average, 2 or less (one polymer chain) of mercapto groups represented by the general formula (1). The average per polymer chain is more preferably 0.1 to 1.8, still more preferably 0.5 to 1.5, and still more preferably 0.8 to 1.2. Here, the number of mercapto groups per polymer chain includes the molar concentration A _{Mn of} a water-soluble synthetic polymer aqueous solution obtained from the number average molecular weight Mn of the polymer when GPC measurement was performed using polyethylene oxide as a reference substance, and the polymer measure the molar concentration QUV determined from UV absorbance of a nitrogen-containing aromatic ring having a mercapto group in the aqueous solution is determined as the value of the QUV / a _Mn. That is, the mercapto group-containing polymer preferably has a QuV / A _Mn of 2 or less, more preferably 1 or less.

  In the mercapto group-containing polymer, the mercapto group represented by the general formula (1) is preferably introduced at one end of the polymer.

  A preferred embodiment of the mercapto group-containing polymer is a polymer represented by the following general formula (2).

In formula, Y < ¹ > and Y < ² > are the terminal groups of X, and at least one represents HS-ZL < ¹ >-. When only ^one of Y ¹ and Y ² represents HS-ZL ^1- , the other may be any group introduced in the process of polymer synthesis, such as a hydrogen atom, a polymerization initiator, a solvent In addition to molecules or monomer derivatives, additive derivatives during synthesis can be the other end group.

L ¹ represents a divalent linking group or a single bond, and is not particularly limited as long as it is a divalent linking group or a single bond, but L ¹ is preferably a divalent linking group having 0 to 20 carbon atoms. Specifically, an alkylene group having 1 to 20 carbon atoms (for example, methylene, ethylene, propylene, butylene, xylylene, etc.), an arylene group having 6 to 20 carbon atoms (for example, phenylene, naphthylene, etc.), -C (= O)-, _{-S (= O) 2 -,} - S (= O) -, - S -, - O -, - P (= O) O - -, - P (= O) O - -, - P (= O ) OR ^a- , -NR ^a- (R ^a represents a hydrogen atom or a substituent, and those described as the substituent T described later can be applied as the substituent), -N =, an aromatic heterocyclic group, Or it is a C2-C20 bivalent coupling group obtained by combining 2 or more types of these. Specific examples are shown below.

  These may be bonded to Z in either the left or right direction, but it is preferable that the left side is bonded to Z.

L ¹ may further have a substituent T if possible, and examples of the substituent T include an alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, and particularly preferably carbon atoms. Examples thereof include methyl, ethyl, iso-propyl, tert-butyl, n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl and the like, and an alkenyl group (preferably. It has 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, particularly preferably 2 to 8 carbon atoms, and examples thereof include vinyl, allyl, 2-butenyl, 3-pentenyl and the like, and an alkynyl group (preferably carbon 2 to 20, more preferably 2 to 12 carbon atoms, particularly preferably 2 to 8 carbon atoms, such as propargyl and 3-pentynyl. An aryl group (preferably having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenyl, p-methylphenyl, naphthyl, etc.), substitution Or an unsubstituted amino group (preferably having 0 to 20 carbon atoms, more preferably 0 to 10 carbon atoms, particularly preferably 0 to 6 carbon atoms, such as amino, methylamino, dimethylamino, diethylamino, dibenzylamino, etc. An alkoxy group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, such as methoxy, ethoxy, butoxy, etc.), aryloxy A group (preferably having 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, Phenyloxy, 2-naphthyloxy and the like),

  An acyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as acetyl, benzoyl, formyl, pivaloyl, etc.), an alkoxycarbonyl group (preferably Has 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, and examples thereof include methoxycarbonyl and ethoxycarbonyl, and aryloxycarbonyl groups (preferably 7 to 7 carbon atoms). 20, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 10 carbon atoms, such as phenyloxycarbonyl, and acyloxy groups (preferably 2 to 20 carbon atoms, more preferably 2 to 2 carbon atoms). 16, particularly preferably 2 to 10 carbon atoms, such as acetoxy, benzoyloxy, etc. An acylamino group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms such as acetylamino and benzoylamino), alkoxycarbonylamino A group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonylamino), an aryloxycarbonylamino group (preferably having a carbon number) 7 to 20, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as phenyloxycarbonylamino, and sulfonylamino groups (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methanesulfo And sulfamoyl groups (preferably having 0 to 20 carbon atoms, more preferably 0 to 16 carbon atoms, particularly preferably 0 to 12 carbon atoms, such as sulfamoyl, methylsulfamoyl, Dimethylsulfamoyl, phenylsulfamoyl, etc.), carbamoyl groups (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as carbamoyl, methyl Carbamoyl, diethylcarbamoyl, phenylcarbamoyl, etc.),

  An alkylthio group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methylthio and ethylthio), an arylthio group (preferably having 6 to 6 carbon atoms) 20, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenylthio, sulfonyl group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, Particularly preferably, it has 1 to 12 carbon atoms, and examples thereof include mesyl, tosyl and the like, and sulfinyl group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms). For example, methanesulfinyl, benzenesulfinyl, etc.), ureido group (preferably having 1 to 20 carbon atoms, more preferably Alternatively, it has 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include ureido, methylureido, phenylureido and the like, phosphoric acid amide group (preferably 1 to 20 carbon atoms, more preferably carbon 1 to 16, particularly preferably 1 to 12 carbon atoms, such as diethyl phosphoric acid amide and phenyl phosphoric acid amide), hydroxy group, mercapto group, halogen atom (for example, fluorine atom, chlorine atom, bromine atom) , Iodine atom), cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, heterocyclic group (preferably having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms). Hetero atoms include, for example, nitrogen atoms, oxygen atoms, sulfur atoms, specifically, for example, imidazolyl, pyridyl, Ril, furyl, piperidyl, morpholino, benzoxazolyl, benzimidazolyl, benzthiazolyl, etc.), silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably carbon number) 3 to 24, and examples thereof include trimethylsilyl and triphenylsilyl). These substituents may be further substituted. Moreover, when there are two or more substituents, they may be the same or different. If possible, they may be linked together to form a ring.

In the general formula (2), X represents a homopolymer or copolymer group of a monomer having an ethylenically unsaturated bond, and when it is a copolymer, a random copolymer, a block copolymer, an alternating Any form of a copolymer and a graft copolymer may be sufficient. Further, when X is a copolymer, there is no particular limitation as to which monomer forms a covalent bond with L ¹ .

  X contains at least one monomer unit (hereinafter referred to as a monomer) having an ethylenically unsaturated bond. The monomer is not particularly limited as long as it is a polymerizable monomer, and any monomer that can be polymerized by radical polymerization or ionic polymerization can be used. As the monomer for X, a monomer in which the homopolymer becomes water-soluble is preferable. As long as the water solubility of X is not impaired, X may be a copolymer of a plurality of monomers.

  Examples of the monomer in which the homopolymer becomes water-soluble include the following monomer group (k), and any of them is preferably used as the X monomer. (K) Acrylic acid, methacrylic acid, acrylamide, N-methylacrylamide, Nn-propylacrylamide, N-isopropylacrylamide, N, N-dimethylacrylamide, N-acryloylmorpholine, N-acryloylpiperidine, methacrylamide, N- Methyl methacrylamide, N-methacryloylmorpholine, N-vinylpyrrolidone, N-vinylacetamide, diacetone acrylamide, ω-methoxypolyethylene glycol acrylate (addition mole number n = 9), ω-methoxypolyethylene glycol acrylate (addition mole number n = 23), N-methoxyethyl acrylamide and the like.

  When X is a copolymer, a copolymer of at least one of the above-mentioned monomer groups (k) and at least one of the monomer groups (a) to (j) shown below Is preferred. In addition, even if it is a monomer to which the above-mentioned (k) monomer group belongs, the thing which belongs to (a)-(j) monomer group was enumerated redundantly.

<< Monomer Group (a) to (j) >>
(A) Conjugated dienes: 1,3-butadiene, isoprene, 1,3-pentadiene, 2-ethyl-1,3-butadiene, 2-n-propyl-1,3-butadiene, 2,3-dimethyl-1, 3-butadiene, 2-methyl-1,3-butadiene, 1-phenyl-1,3-butadiene, 1-α-naphthyl-1,3-butadiene, 1-β-naphthyl-1,3-butadiene, 2- Chloro 1,3-butadiene, 1-bromo-1,3-butadiene, 1-chloro 1,3-butadiene, 2-fluoro-1,3-butadiene, 2,3-dichloro 1,3-butadiene, 1,1 , 2-trichloro 1,3-butadiene, 2-cyano-1,3-butadiene, cyclopentadiene and the like.
(B) Olefin: ethylene, propylene, vinyl chloride, vinylidene chloride, 6-hydroxy-1-hexene, 4-pentenoic acid, methyl 8-nonenoate, vinylsulfonic acid, trimethylvinylsilane, trimethoxyvinylsilane, 1,4-divinyl Cyclohexane, 1,2,5-trivinylcyclohexane and the like.

(C) α, β-unsaturated carboxylic acid esters: alkyl acrylate (eg, methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, etc.), substituted alkyl acrylate (eg, 2-chloro Ethyl acrylate, benzyl acrylate, 2-cyanoethyl acrylate, etc.), alkyl methacrylate (eg, methyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, dodecyl methacrylate, etc.), substituted alkyl methacrylate (eg, 2-hydroxyethyl methacrylate, glycidyl methacrylate) Glycerin monomethacrylate, 2-acetoxyethyl methacrylate, tetrahydrofurfurylme Chryrate, 2-methoxyethyl methacrylate, polypropylene glycol monomethacrylate (polyoxypropylene added mole number = 2 to 100), 3-N, N-dimethylaminopropyl methacrylate, chloro-3-N, N, N-trimethyl Ammoniopropyl methacrylate, 2-carboxyethyl methacrylate, 3-sulfopropyl methacrylate, 4-oxysulfobutyl methacrylate, 3-trimethoxysilylpropyl methacrylate, allyl methacrylate, 2-isocyanatoethyl methacrylate, etc.), unsaturated dicarboxylic acid derivatives (Eg, monobutyl maleate, dimethyl maleate, monomethyl itaconate, dibutyl itaconate, etc.), polyfunctional esters (eg, ethylene glycol diacrylate) Ethylene glycol dimethacrylate, 1,4-cyclohexanediacrylate, pentaerythritol tetramethacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate, trimethylolethane triacrylate, dipentaerythritol pentamethacrylate, pentaerythritol hexaacrylate, 1,2, 4-cyclohexanetetramethacrylate and the like.

(D) Amides of β-unsaturated carboxylic acid: for example, acrylamide, methacrylamide, N-methylacrylamide, N, N-dimethylacrylamide, N-methyl-N-hydroxyethylmethacrylamide, N-tertbutylacrylamide, N- tert-octylmethacrylamide, N-cyclohexylacrylamide, N-phenylacrylamide, N- (2-acetoacetoxyethyl) acrylamide, N-acryloylmorpholine, diacetoneacrylamide, itaconic acid diamide, N-methylmaleimide, 2-acrylamide-2 -Methylpropanesulfonic acid, methylenebisacrylamide, dimethacryloylpiperazine, etc.
(E) Unsaturated nitriles: acrylonitrile, methacrylonitrile and the like.
(F) Styrene and its derivatives: styrene, vinyl toluene, p-tertbutyl styrene, vinyl benzoic acid, methyl vinyl benzoate, α-methyl styrene, p-chloromethyl styrene, vinyl naphthalene, p-hydroxymethyl styrene, p- Aminomethylstyrene, 1,4-divinylbenzene and the like.
(G) Vinyl ethers: methyl vinyl ether, butyl vinyl ether, methoxyethyl vinyl ether and the like.
(H) Vinyl esters: vinyl acetate, vinyl propionate, vinyl benzoate, vinyl salicylate, vinyl chloroacetate, and the like.

(I) Monomers containing acid groups: acrylic acid, sodium acrylate, potassium acrylate, lithium acrylate, ammonium acrylate, methacrylic acid, sodium methacrylate, potassium methacrylate, lithium methacrylate, ammonium methacrylate, itaconic acid , Potassium itaconate, maleic acid, CH ₂ = CHCOOCH ₂ CH ₂ COOH, CH ₂ = CHCONHCH ₂ CH ₂ COOH, CH ₂ = CHC ₆ H ₅ COOH (p), CH ₂ = CHCOOCH ₂ CH ₂ CH ₂ COOH, α -Chloroacrylic acid, sodium styrenesulfonate, ammonium styrenesulfonate, lithium styrenesulfonate, 2-acrylamido-2-methyl-propanesulfonic acid, 2-acrylamido-2-methyl-propanesulfonic acid sodium , Ammonium 2-acrylamido-2-methyl-propanesulfonate, sodium 3-acryloyloxy-propanesulfonate, potassium 3-methacryloyloxy-propanesulfonate, isoprenesulfonic acid, etc., sodium 3-acryloyloxy-ethylphosphonate, etc. .
(J) Other polymerizable monomers: N-vinylimidazole, 4-vinylpyridine, N-vinylpyrrolidone, 2-vinyloxazoline, 2-isopropenyloxazoline, divinylsulfone and the like.

X contains one homopolymer or two or more copolymers selected from the above (k) monomer group, or (k) at least one selected from the monomer group and the above (i) acid group. A copolymer with at least one selected from the monomer group is preferred, and one homopolymer or two or more copolymers selected from the above (k) monomer group are more preferred. A more preferable embodiment of X is a homopolymer of a monomer having a carboxylic acid group or a copolymer of two or more, and an even more preferable embodiment is acrylic acid, methacrylic acid, CH ₂ ═CHCOOCH ₂ CH ₂ COOH, CH ₂ = CHCONHCH ₂ CH ₂ COOH or a homopolymer of CH ₂ = CHCOOCH ₂ CH ₂ CH ₂ COOH or a copolymer of two or more thereof, and a particularly preferred embodiment is a homopolymer of acrylic acid or methacrylic acid, or these acrylic acid, methacrylic _{acid, CH 2 = CHCOOCH 2 CH 2} COOH, CH 2 = CHCONHCH 2 CH 2 COOH or CH ₂ = CHCOOCH copolymers of monomers such ₂ CH ₂ CH ₂ COOH.

  A preferred embodiment of the polymer represented by the general formula (2) is a polymer represented by the following general formula (2-A).

In the formula, R ¹¹ represents a hydrogen atom or a methyl group, preferably a methyl group.

R ¹² and R ¹³ each independently represent a hydrogen atom or a substituent, and the substitution is synonymous with the substituent T described above. R ¹² and R ¹³ are preferably a hydrogen atom or an alkyl group, more preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, still more preferably a hydrogen atom or a methyl group, and particularly preferably a hydrogen atom. Is an atom.

In the formula, X ¹ represents a monomer unit having an ethylenically unsaturated bond, and may be one kind or plural kinds. X ¹ is not particularly limited as long as it can be polymerized, and monomers selected from the monomer groups (a) to (k) exemplified as the monomer of X in the general formula (2) can be used.

In a preferred embodiment of the polymer compound represented by the general formula (2-a), X ¹ is at least one selected from the above (i) monomer group containing an acid group, or X ¹ is absent (that is, n = 0). It is a mode. A more preferred embodiment is an embodiment in which X ¹ is at least one monomer containing a carboxylic acid group, and a further preferred embodiment is that X ¹ is acrylic acid, methacrylic acid, CH ₂ ═CHCOOCH ₂ CH ₂ COOH, CH _2. = CHCONHCH ₂ CH ₂ COOH or CH ₂ = CHCOOCH ₂ CH ₂ CH ₂ COOH is an embodiment, and a particularly preferred embodiment is an embodiment in which X ¹ is acrylic acid or methacrylic acid.

In the formula, m and n represent the mass ratio of the monomer units, and m + n = 100. m is preferably 50 to 100, more preferably 70 to 100, and still more preferably 80 to 100. n is preferably 0 to 50, more preferably 0 to 30, and still more preferably 0 to 20. In the case where X ¹ comprises more than one monomer unit to the total mass ratio of the monomer units and n.

Y ¹ and Y ² are end groups, but at least one of them represents SH-ZL ^1- . Z represents a nitrogen-containing aromatic ring and has the same meaning as Z in the general formula (1), and the preferred range is also the same. L ¹ represents a divalent linking group or a single bond, and has the same meaning as L ¹ in the general formula (2), and the preferred range is also the same.

  A more preferred embodiment of the polymer represented by the general formula (2) is a polymer represented by the following general formula (2-B).

In the formula, X ¹ , R ¹¹ , m ¹ and n ¹ have the same meanings as those in formula (2-A), and preferred ranges are also the same. Y ¹¹ and Y ¹² are terminal groups, and at least one of them represents a group represented by the following general formula (3).

In the formula, L ^1A represents a divalent linking group or a single bond. Not particularly limited as long as divalent linking group or a single bond, but preferably as L ^1A is a divalent linking group having 0 to 14 carbon atoms. Specifically, an alkylene group having 1 to 14 carbon atoms (eg, methylene, ethylene, propylene, butylene, xylylene, etc.), an arylene group having 6 to 14 carbon atoms (eg, phenylene, naphthylene, etc.) —C (═O) —, — _{S (= O) 2 -,} - S (= O) -, - S -, - O -, - P (= O) O - -, - P (= O) O - -, - P (= O) OR ^a- , -NR ^a- (R ^a represents a hydrogen atom or a substituent, and the substituents described above as the substituent T can be applied), -N =, an aromatic heterocyclic group, or these A divalent linking group having 0 to 14 carbon atoms obtained by combining two or more of the above. Specific examples are shown below.

  In the formula, Q represents N, CH or C-SH, preferably N or CH, more preferably N.

  A more preferred embodiment of the polymer represented by the general formula (2) is a polymer represented by the following general formula (2-C).

Wherein, Y ¹¹ and Y ¹² have the same meanings as those in formula (2-B). That is, at least one of Y ¹² and Y ¹² represents a group represented by the general formula (3), and the preferred range is also the same. In the formula, R ¹¹ has the same meaning as R ¹¹ in formula (2-B), and the preferred range is also the same.

In the formula, R ²¹ represents a hydrogen atom or a methyl group, preferably a hydrogen atom.

In the formula, L ² represents a single bond or a divalent linking group, and may be any single bond or a divalent linking group. L ² is preferably a single bond or a divalent linking group having 0 to 20 carbon atoms. More preferably a single bond or a divalent linking group having 0 to 10 carbon atoms, specifically a single bond or an alkylene group having 1 to 10 carbon atoms (for example, methylene, ethylene, propylene, butylene, xylylene). Etc.), an arylene group having 6 to 10 carbon atoms (e.g., phenylene, naphthylene, etc.) -C (= O)-, -S (= O) _2- , -S (= O)-, -S-, -O- ^{, -P (= O) O -} -, - P (= O) O - -, - P (= O) oR a -, - NR a - (R a represents a hydrogen atom or a substituent, as the substituent Are the same as those described above for the substituent T), -N =, an aromatic heterocyclic group, or Is a divalent linking group having 0 to 10 carbon atoms obtained by combining two or more of these, more preferably a single bond or

It is. These may be bonded to the polymer main chain in either the left or right direction, but the left side is preferably bonded to the polymer main chain.

In the formula, m ² and n ² represent the mass ratio of the monomer units, and m ² + n ² = 100. m ² is preferably 50 to 100, more preferably 70 to 100, and still more preferably 80 to 100. n ² is preferably 0 to 50, more preferably 0 to 30, and still more preferably 0 to 20.

  In the formula, M represents a hydrogen atom or a cation. Preferably, they are a hydrogen atom or a sodium ion.

  The molecular weight of the mercapto group-containing polymer is preferably 5,000 or more, more preferably 10,000 or more, still more preferably 30,000 or more, particularly preferably 50,000 or more, and most preferably 100,000. That's it.

  Next, although an example of the general synthesis method of a mercapto group containing polymer is shown, it is not limited to these. Mercapto group-containing polymer introduces the mercapto group by reacting a polymer previously obtained by a polymerization reaction with a compound containing a nitrogen-containing aromatic ring having a mercapto group and capable of forming a covalent bond with a reactive group in the polymer. May be synthesized, or a compound having a nitrogen-containing aromatic ring having a mercapto group may be polymerized together with a monomer. The monomer unit may be polymerized by any polymerization reaction such as radical polymerization, ionic polymerization, condensation polymerization, ring-opening polymerization, and polyaddition.

  Specific examples of the polymer represented by the general formula (2), (2-A), (2-B), or (2-C) are shown below, but the present invention is limited by the following specific examples. Is not to be done.

(Other compounds)
Other dispersion media may be added to the dispersion of the present invention after preparing the metal tabular grains as long as not departing from the spirit of the present invention. Examples of the other additive include a dispersion medium that is preferably added when the metal tabular grain is prepared.

[Method for producing dispersion]
There is no restriction | limiting in particular as a manufacturing method of the dispersion of this invention, It can prepare by a well-known method. For example, after preparing the metal tabular grains by the method described in JP 2011-118347 A, a method of adding a dispersion medium that is preferably added after preparing the metal tabular grains described above may be mentioned. it can. Moreover, when refine | purifying and concentrating a metal tabular grain, the following methods other than the method of Unexamined-Japanese-Patent No. 2011-118347 can also be used preferably.

-Purification and concentration of tabular metal grains-
Moreover, the dispersion of this invention can refine | purify after removing metal impurities other than coexisting metal tabular grain, impurities, such as a residual reducing agent, and can concentrate metal tabular grain simultaneously after metal tabular grain adjustment.
The above purification / concentration method can be any method such as centrifugation, decantation, suction filtration, etc., but from the viewpoint of the heat resistance and heat resistance of the heat ray shielding material when producing the heat ray shielding material, Ultrafiltration is preferred. Regarding the ultrafiltration method, the method used in “The latest membrane treatment technology and its application” published by Fuji Techno System Co., Ltd. can be referred to.

Although it does not specifically limit as a filtration membrane used when wash | cleaning and concentrating a dispersion liquid by ultrafiltration, For example, resin-made things, such as polyacrylonitrile, a vinyl chloride / acrylonitrile copolymer, polysulfone, a polyimide, polyamide, are usually used. Things are used. Of these, polyacrylonitrile and polysulfone are preferable, and polysulfone is more preferable. Further, a ceramics membrane made mainly of Al ₂ O ₃ is also preferable. As the ultrafiltration filtration membrane, it is preferable to use a filtration membrane that can be backwashed from the viewpoint of efficiently washing the filtration membrane that is usually performed after the ultrafiltration.

  By the above purification / concentration method, the ratio of the metal weight in the total solid content contained in the dispersion, that is, the solid content weight ratio of the metal can be concentrated to 40% or more. Further, in order to improve stability and durability in the production of the heat ray shielding material, the solid content weight ratio of the metal is preferably 40% or more, more preferably 60% or more, and most preferably 80% or more.

It is also preferable to add a proteolytic enzyme to the dispersion after the preparation of the metal tabular grains before the purification and concentration. In particular, when gelatin is added when preparing the metal tabular grains, it is preferable from the viewpoint of controlling the molecular weight.
There is no restriction | limiting in particular as said proteolytic enzyme, The following can be used preferably.
For example, pepsin or papain can be preferably used.
The proteolytic enzyme can be obtained and used commercially. For example, actinase E manufactured by Kaken Pharmaceutical Co., Ltd. can be preferably used.

  Moreover, the dispersion of this invention can also perform solvent substitution after metal tabular grain preparation. Solvent replacement can be performed by adding the target solvent to the purified and concentrated dispersion by centrifugation, decantation, suction filtration, or ultrafiltration. For example, when a decantation method is combined, a non-aqueous solvent can be substituted by gradually adding a non-polar solvent from water and sequentially replacing the solvent. When redispersion is performed after solvent replacement, it is preferable to perform mechanical dispersion using ultrasonic waves, a bead mill disperser, or the like. By performing such redispersion, impurities such as the remaining reducing agent can be removed and solvent replacement can be performed.

The solvent used for the solvent substitution is not particularly limited, and among them, those having an SP value of 9.0 or more are preferable. The “SP value” is also called a solubility parameter, and is expressed by the square root of the cohesive energy density. In the present invention, the SP value means that described in page 838 of “Adhesion Handbook” (edited by the Japan Adhesive Society, published by Nikkan Kogyo Shimbun, first published in 1971).
For example, n-hexane / 7.3, toluene / 8.9, ethyl acetate / 9.1, methyl ethyl ketone / 9.3, acetone / 10.0, ethyl alcohol / 12.7, methyl alcohol / 14.5, water /23.4. Here, the unit of the SP value is “(cal / cm ³ ) ^1/2 ”.
When the solvent redispersion has an SP value of 9.0 or more, the dispersibility is particularly good, and methyl ethyl ketone, 2-propanol, 1-propanol, 1-methoxy-2-propyl acetate, cyclohexanone, acetone, N -Methylpyrrolidone or a mixture thereof is preferably raised.

[Heat ray shielding material]
The heat ray shielding material of the present invention includes a metal particle-containing layer obtained by applying the dispersion of the present invention on a substrate.
Such a heat ray shielding material of the present invention is obtained using the dispersion of the present invention that has good dispersion stability over a long period of time, and therefore has excellent heat ray shielding performance even when a dispersion after long-term storage is used. .

(Constitution)
-Metal particle content layer-
In the heat ray shielding material of the present invention, the metal tabular grain has its main plane oriented in a predetermined range with respect to one surface of the metal particle-containing layer (or the substrate surface when the heat ray shielding material has a substrate). Is an embodiment.
The presence state of the metal tabular grains is not particularly limited and may be appropriately selected depending on the intended purpose. However, it is preferable that they are arranged on the substrate as shown in FIG. 2A described later.
As the plane orientation, the main plane of the metal tabular grain and one surface of the metal particle-containing layer (the substrate surface when the heat ray shielding material has a substrate) are substantially parallel within a predetermined range. If it is an aspect, there will be no restriction | limiting in particular, According to the objective, it can select suitably, The angle of a plane orientation is 0 degree-+/- 30 degree, and 0 degree-+/- 20 degree is preferable.
The presence state of the metal tabular grains is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably arranged as shown in FIGS. 3 and 4 described later.

Here, FIGS. 2A to 2C are schematic cross-sectional views showing the existence state of the metal particle-containing layer containing the metal tabular grains in the heat ray shielding material of the present invention. FIG. 2A shows the most ideal state of the metal tabular grains 3 in the metal particle-containing layer 2. FIG. 2B is a diagram for explaining an angle (± θ) formed by the plane of the substrate 1 and the plane of the metal tabular grain 3. FIG. 2C shows the existence region in the depth direction of the heat ray shielding material of the metal particle-containing layer 2.
In FIG. 2B, the angle (± θ) formed by the surface of the substrate 1 and the main plane of the metal tabular grain 3 or an extension line of the main plane corresponds to a predetermined range in the plane orientation. That is, the plane orientation means a state in which the inclination angle (± θ) shown in FIG. 2B is small when the cross section of the heat ray shielding material is observed. In particular, FIG. Are in contact with each other, that is, θ is 0 °. When the angle of the plane orientation of the main plane of the metal tabular grain 3 with respect to the surface of the substrate 1, that is, θ in FIG. The reflectance of the outside light area is lowered or the haze is increased.

  There is no particular limitation on the evaluation of whether or not the main plane of the metal tabular grain is plane-oriented with respect to one surface of the metal particle-containing layer (the surface of the substrate when the heat ray shielding material has a substrate). Can be appropriately selected depending on the purpose, and for example, the method described in JP-A-2011-118347 can be used.

  The plasmon resonance wavelength λ of the metal constituting the metal tabular grain in the metal particle-containing layer is not particularly limited and can be appropriately selected according to the purpose. However, in terms of imparting heat ray reflection performance, 400 nm to 2, The thickness is preferably 500 nm, and more preferably 700 nm to 2,500 nm from the viewpoint of imparting visible light transmittance.

-Base material-
The substrate is not particularly limited as long as it is an optically transparent substrate, and can be appropriately selected according to the purpose. For example, the substrate has a visible light transmittance of 70% or more, preferably 80% or more. And those having a high transmittance in the near infrared region.
There is no restriction | limiting in particular as a material of the said base material, According to the objective, it can select suitably, For example, glass materials, such as white plate glass and blue plate glass, polyethylene terephthalate (PET), triacetyl cellulose (TAC), etc. Is mentioned.

(Method for manufacturing heat ray shielding material)
The method for producing the heat ray shielding material of the present invention is not particularly limited and can be appropriately selected according to the purpose. For example, a dispersion having metal tabular grains on a substrate is used as a dip coater, a die coater, or a slit. Examples of the surface orientation include coating by a coater, bar coater, gravure coater, and the like, LB film method, self-assembly method, spray coating, and the like.

  Moreover, in order to improve the adsorptivity to the substrate surface and plane orientation of the metal tabular grain, a method of plane orientation using electrostatic interaction may be used. Specifically, when the surface of the tabular metal particle is negatively charged (for example, dispersed in a negatively charged medium such as citric acid), the surface of the substrate is positively charged (for example, an amino group or the like). The surface of the substrate may be modified), and the surface orientation may be electrostatically enhanced to achieve surface orientation. If the surface of the metal tabular grain is hydrophilic, a hydrophilic / hydrophobic sea-island structure is formed on the surface of the substrate by a block copolymer or μ contact stamp method, etc., and plane orientation is made using the hydrophilic / hydrophobic interaction. And the distance between the tabular grains may be controlled.

  In addition, in order to accelerate | stimulate plane orientation, after apply | coating a metal tabular grain, you may accelerate | stimulate by passing through pressure-bonding rollers, such as a calender roller and a laminating roller.

(Usage of heat ray shielding material)
The heat ray shielding material of the present invention is not particularly limited as long as it is an embodiment used for selectively reflecting or absorbing heat rays (near infrared rays), and may be appropriately selected according to the purpose. Examples include films, building material films, and agricultural films. Among these, the film for vehicles and the film for building materials are preferable from the viewpoint of energy saving effect.
In addition, in this invention, a heat ray (near infrared rays) means the near infrared rays (780 nm-1,800 nm) contained about 50% in sunlight.

The features of the present invention will be described more specifically with reference to the following examples.
The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.
Examples 1, 2, 11 and 21 are reference examples.

[Example 1]
―Synthesis of metal tabular grains―
2.5 mL of 0.5 g / L polystyrene sulfonic acid aqueous solution was added to 50 mL of 2.5 mmol / L (2.5 mM) sodium citrate aqueous solution and heated to 35 ° C. To this solution, 3 mL of 10 mmol / L sodium borohydride aqueous solution was added, and 50 mL of 0.5 mmol / L silver nitrate aqueous solution was added with stirring at 20 mL / min. This solution was stirred for 30 minutes to prepare a seed solution.
In a reaction kettle, 87.1 mL of ion-exchanged water was added to 132.7 mL of a 2.5 mmol / L sodium citrate aqueous solution and heated to 35 ° C. 2 mL of 10 mmol / L ascorbic acid aqueous solution is added to the above solution in the reaction kettle, 42.4 mL of the seed solution is added, and 79.6 mL of 0.5 mmol / L silver nitrate aqueous solution is added with stirring at 10 mL / min. did. After stirring for 30 minutes, 71.1 mL of 0.35 mol / L potassium hydroquinonesulfonate aqueous solution was added to the reaction kettle, and 200 g of 7 mass% gelatin aqueous solution was added to the reaction kettle. To the above solution in the reaction kettle, a white precipitate mixed solution of silver sulfite formed by mixing 107 mL of a 0.25 mol / L aqueous sodium sulfite solution and 107 mL of a 0.47 mol / L aqueous silver nitrate solution was added. Immediately after the white precipitate mixture was added, 72 mL of a 0.17 mol / L aqueous NaOH solution was added to the reaction kettle. At this time, an aqueous NaOH solution was added while adjusting the addition rate so that the pH did not exceed 10. This was stirred for 300 minutes to obtain a silver tabular grain dispersion (primary dispersion).

  In this silver tabular grain dispersion, it was confirmed that silver hexagonal tabular grains (hereinafter referred to as Ag hexagonal tabular grains) having an average equivalent circle diameter of 200 nm were formed. Further, when the thickness of the hexagonal tabular grains was measured with an atomic force microscope (Nanocute II, manufactured by Seiko Instruments Inc.), it was found that tabular grains having an average of 12 nm and an aspect ratio of 16.7 were generated. .

-Preparation of secondary dispersion of the present invention-
800 mL of the silver tabular grain dispersion (primary dispersion) was kept at 40 ° C. and adjusted to pH = 10 using 1N NaOH and / or 1N sulfuric acid. Water-insoluble phenyl mercaptotetrazole (trade name: 5-mercapto-1-phenylmercaptotetrazole, manufactured by Wako Pure Chemical Industries, Ltd.) was further added as a dispersant, and stirring was continued for 10 minutes. The addition amount was 1.0% in terms of a molar ratio with respect to silver. This was centrifuged for 60 minutes at 9000 rpm with a centrifuge (Himac CR-GIII, manufactured by Hitachi Koki Co., Ltd.), and 760 mL of the supernatant was discarded. The precipitated silver tabular grains were transferred to a desktop homogenizer (Mitsui Denki Seiki Co., Ltd., SpinMix08), 160 mL of 0.2 mmol / L NaOH aqueous solution was added, and dispersed at 12000 rpm for 20 minutes. 200 mL of 0.2 mmol / L NaOH aqueous solution was added to the obtained dispersion, and this was used as the secondary dispersion of Example 1.

―Production of heat shielding material―
To 200 mL of the obtained secondary dispersion, 560 mL of ion exchange water and 240 mL of methanol are added. Subsequently, 28.2 mL of polyester latex aqueous dispersion (trade name Finetex ES-650, manufactured by DIC, solid content concentration: 30% by mass), surfactant A (trade name: Rapisol A-90, manufactured by Nippon Oil & Fats Co., Ltd.) , 12.5 mL of solid content (1% by mass), 15.5 mL of surfactant B (trade name: Alonacty CL-95, manufactured by Sanyo Chemical Industries, Ltd., 1% by mass of solid content) was added, stirred, and secondary A coating solution containing the dispersion was prepared.
Using a wire bar on the surface of a PET film (Fujipet, manufactured by Fuji Film Co., Ltd., thickness: 188 μm) using this coating solution as a base material, the average thickness after drying is 0.08 μm. did. Then, it heated at 150 degreeC for 10 minute (s), dried and solidified, and formed the metal particle content layer.
After depositing a carbon thin film on the obtained PET film so as to have a thickness of 20 nm, SEM observation (manufactured by Hitachi, FE-SEM, S-4300, 2 kV, 20,000 times) was performed. It was found that the Ag hexagonal tabular grains were fixed on the PET film without aggregation, and the area ratio of the Ag hexagonal tabular grains measured as described above to the substrate surface was 45%. The heat ray shielding material of Example 1 was produced by the above.

[Example 2]
In preparation of the secondary dispersion of Example 1, water-soluble PMT (manufactured by Wako Pure Chemical Industries, Ltd., trade name 1- (m-sulfophenyl) -5-mercapto-1H-tetrazole instead of water-insoluble PMT as a dispersant was used. A secondary dispersion of Example 2 was obtained in the same manner as Example 1 except that 1.6 g of sodium) was added. A heat ray shielding material of Example 2 was produced in the same manner as in Example 1 except that the obtained dispersion liquid of Example 2 was used (the addition amount was adjusted so that the amount of silver in the coating solution was the same). ).

[Example 3]
In the secondary dispersion preparation of Example 1, 1.6 g of a polymer having a nitrogen-containing aromatic ring having a mercapto group as a partial structure (WP-3 below) was added as a dispersant instead of water-insoluble PMT. The secondary dispersion of Example 3 was obtained in the same manner as Example 1. A heat ray shielding material of Example 3 was produced in the same manner as in Example 1 except that the obtained dispersion liquid of Example 3 was used (the addition amount was adjusted so that the silver amount in the coating solution was the same). ).

[Comparative Example 1]
In preparing the secondary dispersion of Example 1, a secondary dispersion of Comparative Example 1 was obtained in the same manner as in Example 1 except that the water-insoluble PMT was not added as a dispersant. A heat ray shielding material of Comparative Example 1 was produced in the same manner as in Example 1 except that the obtained dispersion liquid of Comparative Example 1 was used (the addition amount was adjusted so that the amount of silver in the coating solution was the same). ).

[Comparative Example 2]
In the preparation of the secondary dispersion of Example 1, high molecular weight gelatin (manufactured by Nitta Gelatin Co., Ltd., number average molecular weight 200,000, molecular length of about 3000 mm) is added as a dispersant instead of water-insoluble PMT. A secondary dispersion of Comparative Example 2 was obtained in the same manner as Example 1 except that. A heat ray shielding material of Comparative Example 2 was produced in the same manner as in Example 1 except that the obtained dispersion liquid of Comparative Example 2 was used (the addition amount was adjusted so that the amount of silver in the coating solution was the same). ).

[Evaluation]
(Dispersion stability)
With respect to the dispersions of the above Examples and Comparative Examples, the dispersibility of the silver particles after being allowed to stand for 3 days in an environment of 20 ° C. was evaluated according to the following four criteria.
"Evaluation criteria"
(Double-circle): The silver particle as a dispersoid maintains the dispersion state in a very highly uniform state.
○: Precipitation of silver particles or the like is not observed, but slight shading considered to be derived from variation in the size of silver particles is observed in the dispersion.
Δ: Slight precipitation of silver particles is observed.
X: Precipitation of silver particles is noticeable.

(Heat ray shielding performance)
When the same dispersion is used, the relationship between the visible light transmittance and the shielding coefficient of each heat ray shielding material changes with a certain slope depending on the coating amount. Therefore, a large number of heat ray shielding materials were produced for each Example and Comparative Example by changing the coating amount of the dispersion of each Example and Comparative Example. For the heat ray shielding performance, the visible light transmittance and shielding coefficient are measured by the following method, the visible light transmittance and shielding coefficient are set with the x axis as the visible light transmittance (unit%) and the y axis as the shielding coefficient (no unit). The graph which plotted the relation of was made. The obtained plot is approximated to a linear curve (straight line), and the obtained linear curve is extrapolated to obtain an x-intercept value specific to each dispersion (visible light transmittance value when the shielding coefficient is 0 (unit%)). )
(1) Measuring method of visible light transmittance About each produced heat ray shielding material, the value which correct | amended the transmittance | permeability of each wavelength measured from 380 nm to 780 nm with the spectral visibility of each wavelength was made visible light transmittance.
(2) Measuring method of shielding coefficient About each produced heat ray shielding material, the shielding coefficient was calculated | required based on the method of JIS5759 from the transmittance | permeability of each wavelength measured to 350 nm-2,100 nm.
"Evaluation criteria"
(Double-circle): x intercept is + 1% or more on the basis of the x intercept of the primary curve in the graph created using the dispersion of Example 1 immediately after preparation.
(Circle): x intercept is -1% or more and less than + 1% on the basis of x intercept of the primary curve in the graph created using the dispersion of Example 1 immediately after preparation.
(Triangle | delta): x intercept is -4% or more and less than -1% on the basis of x intercept of the primary curve in the graph created using the dispersion of Example 1 immediately after preparation.
X: The x intercept is less than −4% based on the x intercept of the primary curve in the graph prepared using the dispersion of Example 1 immediately after preparation.
The results are shown in Table 1 below.

上記表中、ＰＭＴはフェニルメルカプトテトラゾールの略称を意味する。

In the above table, PMT means an abbreviation for phenylmercaptotetrazole.

From Table 1 above, it was found that the dispersions of Examples 1 to 3 using phenylmercaptotetrazole as the dispersant were excellent in long-term stability. Moreover, also when manufacturing a heat ray shielding material using the dispersion of Examples 1-3 preserve | saved for a long term, it turned out that heat ray shielding performance becomes favorable.
In addition, the dispersions of Examples 2 and 3 were evaluated as “△” and “◯”, respectively, when the dispersion stability test was conducted after long-term storage for 1 month. The evaluation was also “△” and “◯”, respectively.
On the other hand, from Comparative Example 1, it was found that when no dispersant was used, the dispersion stability was poor after one week. From Comparative Example 2, it was found that when high molecular weight gelatin was added as a dispersant, the heat ray shielding performance deteriorated.

[Example 11]
400 mL of the silver tabular grain dispersion liquid (primary dispersion liquid) in Example 1 was kept at 40 ° C. and adjusted to pH = 10 using 1N NaOH and / or 1N sulfuric acid. As a dispersant, 1- (m-sulfophenyl) -5-mercapto-1H-tetrazole sodium (manufactured by Wako Pure Chemical Industries, Ltd.), which is a water-soluble PMT, was added with stirring, and stirring was continued for 10 minutes. The addition amount was 1.0% in terms of a molar ratio with respect to silver. Subsequently, 1.6 g of Actinase E manufactured by Kaken Pharmaceutical Co., Ltd. was added as a proteolytic enzyme, and stirring was continued for 60 minutes while maintaining 40 ° C. Thereafter, ultrafiltration was performed without centrifugation. For ultrafiltration, Microsa MF pencil type module PSP-003 manufactured by Asahi Kasei was used. First, 200 mL was subjected to concentration filtration, and then washed and filtered by adding 1000 mL of ion-exchanged water while maintaining the volume of 200 mL (diafiltration). Filtration was performed at 40 ° C., and the outlet valve was adjusted so that the inlet pressure of the module was 80 kPa at maximum. The pump flow rate was set so that the linear velocity in the module was 25 cm / sec. The filtration was terminated when the ion-exchanged water was used up. The secondary dispersion was heated to 80 ° C. and maintained for 2 hours, and then returned to room temperature. A secondary dispersion was thus obtained. A heat ray shielding material of Example 11 was produced in the same manner as in Example 1 except that the obtained secondary dispersion of Example 11 was used (the amount added was set so that the amount of silver in the coating solution was the same). Adjusted).

[Example 12]
In the secondary dispersion preparation of Example 11, except that 1.6 g of a polymer (WP-3) having a nitrogen-containing aromatic ring having a mercapto group as a partial structure instead of water-soluble PMT was added as a dispersant. In the same manner as in Example 11, a secondary dispersion of Example 12 was obtained. A heat ray shielding material of Example 12 was produced in the same manner as in Example 1 except that the obtained dispersion liquid of Example 12 was used (the addition amount was adjusted so that the amount of silver in the coating solution was the same). ).

[Comparative Example 11]
In the preparation of the secondary dispersion of Example 11, a secondary dispersion of Comparative Example 11 was obtained in the same manner as in Example 11 except that the water-soluble PMT as a dispersant was not added and no proteolytic enzyme was added. . A heat ray shielding material of Comparative Example 11 was produced in the same manner as in Example 1 except that the obtained dispersion liquid of Comparative Example 11 was used (the addition amount was adjusted so that the silver amount in the coating solution was the same). ).

[Comparative Example 12]
In the secondary dispersion preparation of Example 11, a secondary dispersion of Comparative Example 11 was obtained in the same manner as in Example 11 except that the water-soluble PMT as a dispersant was not added. A heat ray shielding material of Comparative Example 11 was produced in the same manner as in Example 1 except that the obtained dispersion liquid of Comparative Example 11 was used (the addition amount was adjusted so that the silver amount in the coating solution was the same). ).

上記表中、ＰＭＴはフェニルメルカプトテトラゾールの略称を意味する。

In the above table, PMT means an abbreviation for phenylmercaptotetrazole.

From the results of Table 2 above, it was found that the dispersions of Examples 11 and 12 using phenylmercaptotetrazole as a dispersant were excellent in long-term stability.
In addition, the dispersions of Examples 11 and 12 were evaluated as “Δ” and “◯”, respectively, when the dispersion stability test was conducted after long-term storage for 1 month. Furthermore, the dispersion of Example 12 was evaluated as “◯” when the heat ray shielding test was conducted after long-term storage for 1 month.

[Examples 21 and 22]
In Examples 11 and 12, as an ultrafilter, instead of Asahi Kasei Microza and pencil-type module PSP-003, Cefilt Test LAB (NGK Sepilt (MF, 0.1 μm) was used as a filter membrane). A dispersion and a heat ray shielding material of each example were produced in the same manner except that.
When the dispersions and heat ray shielding materials obtained in the respective examples were also evaluated in the same manner as in Examples 11 and 12, results similar to those in Examples 11 and 12 were obtained.

  The heat ray shielding material of the present invention has high visible light transmittance and high solar reflectance, and is excellent in heat shielding performance. For example, films for automobiles, buses, etc., laminated structures, films for building materials, laminated structures, etc. As such, it can be suitably used as various members that are required to prevent the transmission of heat rays.

DESCRIPTION OF SYMBOLS 1 Base material 2 Metal particle content layer 3 Metal tabular grain

Claims (8)

Metal tabular grains;
Including at least one compound having a nitrogen-containing aromatic ring structure having a mercapto group,
The metal tabular grains are dispersed in a dispersion medium containing at least a compound having a nitrogen-containing aromatic ring structure having the mercapto group ,
The dispersion having a nitrogen-containing aromatic ring structure having the mercapto group is a polymer represented by the following general formula (2) .

(In the formula, X represents a homopolymer or copolymer group of a monomer having an ethylenically unsaturated bond. Y ¹ and Y ² are end groups of X, and at least one of them is HS-ZL. ¹ - only one of the .Y ¹ and Y ² represent a is HS-Z-L ¹ - for representing, other good .L ¹ be any group that is introduced in the polymer synthesis process of the divalent linking of Represents a group or a single bond, and Z represents a nitrogen-containing aromatic ring.)   The dispersion according to claim 1, wherein the metal tabular grains are substantially hexagonal to disk-shaped tabular grains.   3. The dispersion according to claim 2, wherein an average particle diameter of the substantially hexagonal to substantially disk-shaped metal tabular grains is 70 nm to 500 nm.   4. The dispersion according to claim 2, wherein an aspect ratio (average particle diameter / average particle thickness) of the substantially hexagonal to substantially disk-shaped metal tabular grains is 8 to 40. 5.   The dispersion according to any one of claims 1 to 4, wherein the compound having a nitrogen-containing aromatic ring structure having a mercapto group is water-soluble. The dispersion according to any one of claims 1 to 5 , wherein the nitrogen-containing aromatic ring structure having a mercapto group is a mercaptotetrazole group or a mercaptotriazole group. The said metal tabular grain contains silver at least, The dispersion as described in any one of Claims 1-6 characterized by the above-mentioned. A heat ray shielding material comprising a metal particle-containing layer obtained by applying the dispersion according to any one of claims 1 to 7 on a substrate.

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