WO2002094954A1

WO2002094954A1 - Process for producing high-concentration colloidal metal solution

Info

Publication number: WO2002094954A1
Application number: PCT/JP2001/004215
Authority: WO
Inventors: Taizou Nanke; Hideo Ishibashi; Toshikatsu Kobayashi; Makiko Mori; Manabu Fujita
Original assignee: Nippon Paint Co., Ltd.
Priority date: 2001-05-21
Filing date: 2001-05-21
Publication date: 2002-11-28
Also published as: JPWO2002094954A1; TW583288B; CN1443227A

Abstract

A process by which a colloidal metal solution having a high metal concentration can be obtained even when a large amount of a polymeric pigment dispersant is used in order to secure dispersion stability. The process is characterized by partly removing a polymeric pigment dispersant from a solution containing colloidal metal particles and the polymeric pigment dispersant.

Description

Description Method for producing high concentration solution of metal colloid

The present invention relates to a method for producing a high-concentration metal colloid solution, a high-concentration metal colloid solution obtained by the production method, and a film obtained using the high-concentration metal colloid solution. Background art

A so-called metal colloid solution in which several 10 nm metal particles are uniformly dispersed in a solution has been utilized in various fields by utilizing its features. Japanese Patent Application Laid-Open No. H11-080647 discloses that a precious metal colloid particle containing a precious metal colloid particle and a polymer pigment dispersant and a method for producing the same can be used as a colorant in a paint or the like. Have been. Japanese Patent Application Laid-Open No. 2000-239853 discloses that the above-mentioned noble metal colloid particles are used for producing a thin film having metallic luster. Here, from the viewpoint of obtaining a metal-like film having an excellent appearance, it is desirable that the metal content is high.

On the other hand, conductive films are used in various electronic devices, electronic components, electronic circuits, and the like as electrode materials for capacitors and chip resistors, and as conductor circuits on ceramic substrates. Such a conductive film is usually produced by applying a conductive paste containing metal particles. Even in this case, it is desirable that the metal content be high in order to obtain high conductivity.

However, in the production of the precious metal colloid particles containing the polymer pigment dispersant, if the amount of the polymer pigment dispersant used is reduced in order to increase the metal concentration, dispersion stability during reduction may not be ensured. There is. Summary of the Invention An object of the present invention is to provide a production method capable of obtaining a metal colloid high-concentration solution having a high metal concentration even when a large amount of a polymer-containing dispersant is used to ensure dispersion stability. I do.

The present invention is a method for producing a high-concentration metal colloid solution, comprising removing a part of the polymer pigment dispersant from the solution containing the metal colloid particles and the polymer pigment dispersant. The removal of a part of the polymer pigment dispersant is preferably performed by centrifugation, and the centrifugation is more preferably performed at 100 G or more. The removal of a part of the polymer pigment dispersant is preferably performed by ultrafiltration, and the ultrafiltration has a molecular weight cut-off of 300 to 800,000. It is more preferable to use a certain filtration membrane.

The solution containing the metal colloid particles and the polymer pigment dispersant is preferably obtained by reducing a metal compound in the presence of the polymer pigment dispersant. The metal concentration in the solid content of the solution containing the metal colloid particles and the polymer pigment dispersant is

It is preferably 85% by mass or less, and the metal concentration in the solid content of the metal colloid high concentration solution is preferably 90 parts by mass or more.

The difference between the metal concentration in the solid content of the metal colloid high concentration solution and the solution containing the metal colloid particles and the polymer pigment dispersant is preferably 10% by mass or more.

The present invention also provides a metal colloid high concentration solution obtained by the above production method.

The present invention further provides a film obtained by using the above-mentioned metal colloid high concentration solution. Detailed Disclosure of the Invention

Hereinafter, the present invention will be described in detail.

The method for producing a metal colloid high-concentration solution of the present invention is to increase the metal concentration in solids by removing a part of the polymer pigment dispersant from the solution containing the metal colloid particles and the polymer pigment dispersant. It is.

The solution containing the metal colloid particles and the polymer pigment dispersant is a polymer pigment dispersant. It is obtained by reducing a metal compound in the presence.

The metal compound generates a metal ion when dissolved in a solvent, and the metal ion is reduced to supply metal colloid particles. The metal to be the metal colloid particles is not particularly limited, but is preferably a noble metal or copper from the viewpoint of obtaining an excellent conductive film or metal-like film. The noble metal is not particularly limited, and examples thereof include gold, silver, ruthenium, rhodium, palladium, osmium, iridium, and platinum. Of these, gold, silver, platinum and palladium are preferred. The metal compound is not particularly limited as long as it contains the above-mentioned metal. Examples thereof include tetrachloro base (III) acid tetrahydrate (chloroauric acid), silver nitrate, silver acetate, and silver perchlorate (IV ), Hexaclo mouth platinum (IV) acid hexahydrate (chloroplatinic acid), potassium chloride chloroaurate, copper (II) chloride dihydrate, copper sulfate (II) monohydrate, copper sulfate ( II), palladium chloride (II) dihydrate, rhodium trichloride (III) trihydrate and the like. One or more of these can be used. The above metal compound is preferably used so that the molar concentration of the metal in the solvent is not less than 0.01mo1Z1. If it is less than 0.0 lmo 1/1, the obtained metal colloid solution has too low a molar concentration of metal, which is not efficient. It is preferably at least 0.05 mo 1/1 and more preferably at least 0.1 lmo 1/1.

The solvent is not particularly limited as long as it can dissolve the metal compound, and examples thereof include water and an organic solvent. The organic solvent and the like are not particularly limited, and include, for example, alcohols having 1 to 4 carbon atoms such as ethanol and ethylene glycol; ketones such as acetone and esters such as ethyl acetate. One or more of the above solvents can be used. When the solvent is a mixture of water and an organic solvent, the organic solvent is preferably a water-soluble solvent, and examples thereof include acetone, methanol, ethanol, and ethylene glycol. In the present invention, a mixed solution of water, alcohol, and water and alcohol is preferable from the viewpoint of being suitable for a method of removing a part of the polymer pigment dispersant such as ultrafiltration performed in a subsequent step.

The above-mentioned polymer pigment dispersant has a high affinity for a high molecular weight polymer with respect to the pigment surface. It is an amphiphilic copolymer having a functional group introduced and having a structure containing a solvation moiety, and is usually used as a pigment dispersant during the production of a pigment paste.

It is considered that the polymer pigment dispersant coexists with the metal colloid particles, and functions to stabilize the metal colloid particles from being dispersed in the solvent. The number average molecular weight of the polymeric pigment dispersant is preferably from 1,000 to 1,000,000. If it is less than 1000, dispersion stability 1 to raw material may not be sufficient, and if it exceeds 1,000,000, the viscosity may be too high and handling may be difficult. More preferably, it is 2,000 to 500,000, and further preferably, it is 4,000 to 500,000.

The polymer pigment dispersant is not particularly limited as long as it has the above-mentioned properties, and examples thereof include those exemplified in JP-A-11-80647.

As the polymeric pigment dispersant, various ones can be used, and commercially available ones can also be used. Examples of the commercially available products include Solsperse 20 000, Sonoresperse 24000, Sonoresperse 26000, Solsperse 27 000, Solsperse 28000, Solsperse 41090 (all manufactured by Abyssia), and Disha. One Big 160, Day Spavic 161, Day Spavic 1

62, Disha ° One Big 163, Dis Per Big 166, Day Spa Big 1

70, Disha. One Big 180, Day Spa Big 181, Day Spa Big 1 82, Day Spa ヽ⁰ — Big One 183, Day Spa Big 184, Day Spa Big

1 90, Day Spavik 1 91, Day Spavik 1 92, Day Spavik

— 2000, DISPERVIC-I 2001 (above, manufactured by BIC-Chemie), Polymer 100, Polymer 120, Polymer 150, Polymer 400, Polymer 401, Polymer 402, Polymer 403, Polymer 450, Polymer 451, Polymer 452, Polymer One 453, EFKA—46, EFKA—47, EFKA—48, EFKA—49, EFKA—5011, EFKA—1502, EFKA—4540, EFKA—4550 (all manufactured by EFKA Chemikanore), Floren DOPA

— 1 58, Floren DOPA—22, Floren DOPA—17, Floren G—700, Floren TG—720 W, Floren—730 W, Floren—740 W, Floren—745 W, (Kyoeisha Chemical Co., Ltd.) Azispar PB 711, Azispar PB 811, Azispar PB 821, Azispar PW 911 (or more, manufactured by Ajinomoto Co.), John Krill 678, John Taryl 679, John Krill 6 2 (or more, Johnson Polymer Co., Ltd.). These may be used alone or in combination of two or more.

The amount of the polymer pigment dispersant used was 15 mass based on the total amount of the metal in the metal compound and the polymer pigment dispersant. / ₀ or more is preferable. 15 mass. If it is less than / ₀ , the dispersion stability at the time of reduction may be reduced, and the significance of increasing the metal concentration is reduced. The upper limit is not particularly limited, but may be, for example, 10 times or less the mass of the metal in the metal compound.

The metal compound can be reduced to a metal using a reducing compound in the presence of the polymer pigment dispersant described above. The reducing compound is preferably an amine. By adding the amine to a solution of the metal compound and the polymer pigment dispersant, stirring and mixing, the metal ion is reduced to a metal at around room temperature. By using the above amine, it is not necessary to use a highly hazardous or harmful reducing agent, and without heating or using a special light irradiation device, about 5 to 100 ° C., preferably The metal compound can be reduced at a reaction temperature of about 20 to 80 ° C.

The above-mentioned amine is not particularly limited, and for example, those exemplified in JP-A-11-18747 can be used.Propylamine, ptinoleamine, hexylamine, getylamine, dipropylamine, dimethylethyl , Dimethylamineamine, triethynoleamine, ethylenediamine, N, N, N ', Ν'-tetramethinoleethylenediamine, 1,3-diaminopropane, Ν, Ν, Ν !, Ν' — Aliphatic amines such as tetramethyl-1,3-diaminopropane, triethylenetetramine and tetraethylenepentamine; piperidine, ぺ -methylbiberidine, piperazine, N, N'-dimethinolepiperazine, pyrrolidine, Ν-methyl / Alicyclic amines such as lepirrolidine and morpholine; aniline, Ν-methylaniline, Ν, Ν-dimethylamine Aromatic amines such as phosphorus, toluidine, acidin, and phenetidine Aralkylamines such as penzinoleamine, N-methinole pentinoleamine, N, N-dimethinolebenzinoleamine, phenetinoleamine, xylylenediamine, N, N, Ν ', N'-tetramethylxylylenediamine; be able to. Examples of the above amines include, for example, methylaminoethanol, dimethylaminoethanol, triethanolamine, ethanolamine, diethanolamine, methyljetanolamine, propanolamine, 2- (3-aminopropinoleamino) ethanol And alkanolamines such as butanolamine, hexanolamine and dimethylaminopropanol. Of these, alkanolamine is preferred, and dimethylethanolamine is more preferred.

In addition to the above amines, alkali metal borohydrides such as sodium borohydride, which have been conventionally used as reducing agents; hydrazine compounds; citric acid; tartaric acid; ascorbic acid; formic acid; formaldehyde; Salts, sulfoxylate derivatives and the like can be used. From the viewpoint of easy availability, citric acid; tartaric acid; and ascorbic acid are preferred. These can be used alone or in combination with the above-mentioned amines. Is preferred. In addition, cunic acid or a sulfoxylate derivative can be used in combination with iron (II) ion to improve the reducibility.

The amount of the reducing compound to be added is preferably not less than the amount necessary for reducing the metal in the metal compound. If the amount is less than this, the reduction may be insufficient. The upper limit is not particularly limited, but is preferably 30 times or less, more preferably 10 times or less the amount required for reducing the metal in the metal compound.

In addition to the method of chemically reducing by adding these reducing compounds, it is also possible to use a method of irradiating light with a high-pressure mercury lamp.

The method for adding the reducing compound is not particularly limited. For example, the method can be performed after adding the polymer pigment dispersant. In this case, for example, first, the polymer pigment dispersant is dissolved in a solvent. Further, any of the above reducing compounds or metal compounds By adding the remaining one of the reducing compound or the metal compound to the solution obtained by dissolving the compound, the reduction can proceed. As a method for adding the reducing compound, a mode in which the polymer pigment dispersant and the reducing compound are mixed in advance and the mixture is added to the solution of the metal compound may be employed.

By the above reduction, the average particle size becomes about 5 η π! A solution containing metal colloid particles of up to 100 nm is obtained.

The solution after the reduction contains the metal colloid particles and the polymer pigment dispersant, and becomes a colloid solution. The above-mentioned colloid solution means a solution in which metal fine particles are dispersed in a solvent and can be visually recognized as a solution.

The solution after the reduction contains, in addition to the metal colloid particles and the polymer pigment dispersant, miscellaneous ions such as chloride ions derived from the raw material of the metal colloid solution, salts generated by reduction, and optionally amine. Since these miscellaneous ions and chloride may adversely affect the stability of the obtained metal colloid solution, it is desirable to remove them. To remove these components, electrodialysis, centrifugation, and ultrafiltration are used.However, as described later, when the centrifugation and ultrafiltration are used, the metal concentration is increased at the same time. preferable.

In the method for producing a metal colloid high-concentration solution of the present invention, the metal concentration is increased by removing a part of the polymer pigment dispersant. Here, the metal colloid solution from which a part of the high molecular pigment dispersant is removed has a solid content of the metal colloid particles and the high molecular pigment dispersant of 0.05 to 50% by mass. It is preferable that there is. If it is less than 0.05%, the molar concentration of the metal is too low, which is inefficient. If it exceeds 50%, it may be difficult to remove a part of the polymer pigment dispersant. Further, the metal concentration in the solid content is preferably 85% by mass or less.

Methods for removing a part of the polymer pigment dispersant include centrifugation and ultrafiltration.

By performing the centrifugation, the metal colloid particles precipitate, but the unnecessary miscellaneous ions, chloride, and the high molecular pigment dispersant are dissolved in the supernatant. Therefore, these components can be removed by removing the supernatant. The metal colloid particles remaining in this manner can be washed by adding a solvent, and the centrifugal separation can be repeated to enhance the removal effect.

The centrifugation is preferably performed at 1000 G or more. If it is less than 1000 G, it may be difficult to remove a part of the polymer pigment dispersant. The conditions for centrifugation differ depending on the particle size of the metal colloid. For example, in order to sediment particles of the order of several nm in particle size, it is necessary to carry out so-called ultracentrifugation conditions. Standard conditions include 3000 G for 5-60 minutes, preferably 15-45 minutes.

In the centrifugation, the metal colloid particles can be fractionated based on the particle size by appropriately changing the conditions of the gravitational acceleration, the time, the Z, and the number of operations. By the above-described fractionation, a high-concentration solution of metal colloid particles having a particle size suitable for various uses can be obtained, and the particle size of the metal colloid particles can be made uniform to some extent.

The high concentration metal colloid solution obtained by the centrifugation is concentrated and usually takes the form of a paste. It is preferable that the concentration is generally 80% or more on a mass basis. The upper limit is not specified, but considering the ease of handling, it is 90% or less.

Ultrafiltration may be used as a method for removing a part of the above-mentioned polymer pigment dispersant. The ultrafiltration (Ultrafiltrattion: UF) has a smaller sieve than a filtration membrane used for microfiltration (Microfiltration: MF). Ultrafiltration is generally used for the purpose of separating high molecular weight substances and colloidal substances. In the present invention, it is used to increase the metal concentration in the solid content of the metal colloid solution.

In the ultrafiltration, the diameter of the substance to be separated is usually 1 nn! ~ 5 / zm. By targeting the above diameter, the polymer pigment dispersant as well as the unnecessary miscellaneous ions, salts and amines can be removed, and the metal concentration in the solid content of the metal colloid solution can be increased. If it is less than l nm, unnecessary components cannot be eliminated without passing through the filtration membrane When the value exceeds, many of the metal colloid particles pass through the filtration membrane, and a desired metal colloid high concentration solution may not be obtained.

The filtration membrane for the ultrafiltration is not particularly limited, but usually, for example, a resin membrane such as polyacrylonitrile, butyl chloride Z acrylo-tolyl copolymer, polysulfone, polyimide, or polyamide is used. Of these, polyatarilonitrile and polysulfone are preferred, and polyacrylonitrile is more preferred. As the filtration membrane for the ultrafiltration, it is preferable to use a filtration membrane capable of backwashing from the viewpoint of efficiently performing the filtration membrane usually performed after the end of the ultrafiltration.

As the filtration membrane for the ultrafiltration, those having a molecular weight cut-off of from 300 to 800,000 are preferable. If it is less than 300, the unnecessary polymer pigment dispersant or the like is difficult to be sufficiently removed, and if it is more than 800, the metal colloid particles easily pass through the filtration membrane. In some cases, a metal colloid solution cannot be obtained. More preferably, it is from 1,000 to 600,000. The molecular weight cut-off generally refers to the molecular weight of the polymer that passes through the pores of the ultrafiltration membrane and is excluded when passing the polymer solution through the ultrafiltration membrane. Used to evaluate. The larger the above-mentioned molecular weight cut-off, the larger the pore size of the filtration membrane.

The form of the filtration module for the ultrafiltration is not particularly limited, and examples thereof include a hollow paper module (also called a capillary module), a spiral module, a tubular module, and a plate module depending on the form of the filtration membrane. All are suitably used in the present invention. Among them, the hollow paper type module having a compact form for the filtration area is preferable from the viewpoint of efficiency because the time required for filtration can be shortened as the membrane area is large. If the amount of the metal colloid solution to be treated is large, it is preferable to use a large number of filtration membranes to be used.

The ultrafiltration method is not particularly limited. For example, a conventionally known method is used. Usually, the solution containing the metal colloid particles and the polymer pigment dispersant obtained by the above-described reaction is subjected to ultrafiltration. This is done by passing through a membrane, whereby the filtrate containing the above-mentioned miscellaneous, salt and amine-polymer pigment dispersants is eliminated. The ultrafiltration is Usually, the process is repeated until the above-mentioned miscellaneous ions in the filtrate are removed to a desired concentration or less. At that time, it is preferable to add the same amount of the solvent as the amount of the removed filtrate in order to keep the concentration of the metal colloid solution to be treated constant. By using a solvent different from the one used during the reduction as the solvent added at this time, it is possible to replace the solvent of the metal colloid solution.

The ultrafiltration can be performed by a usual operation, for example, a so-called batch method. In this batch method, the metal colloid solution to be treated is added as much as the ultrafiltration has progressed. The ultrafiltration can be further performed after the miscellaneous ions have been removed to a desired concentration or less to increase the solid content concentration. The specific value of the metal colloid high concentration solution obtained by centrifugation and ultrafiltration differs depending on the value of the metal concentration in the solid content in the solution containing the metal colloid particles and the polymer pigment dispersant before the treatment. However, the metal concentration in the solid content is higher than before the treatment. Preferably, the metal concentration in the solid content of the solution containing the metal colloid particles and the polymer pigment dispersant before the treatment is 85% by mass or less, and the metal concentration in the solid content of the treated high-concentration metal colloid solution is obtained. Is 90 mass. /. That is all. Preferably, the difference between the metal concentrations before and after the treatment is 10% by mass or more.

The solid content of the metal colloid high-concentration solution obtained by the centrifugation is higher than that obtained by the ultrafiltration, but finally, the solid content becomes 1 to 5 by adding a solvent. It is preferably adjusted to 0% by mass. Also in this case, it is possible to replace the solvent of the metal colloid solution by using a different type of solvent as the solvent to be added during the reduction.

Since the metal colloid high-concentration solution obtained in this way has a high metal concentration in the solid content, it can sufficiently exhibit properties of the metal such as high conductivity, metallic luster, coloring, and thermal conductivity. . The above-mentioned metal colloid solution is suitable for forming a metallic film by applying it on a substrate since the above-mentioned polymer pigment dispersant is removed to a low concentration. The method of applying the composition to the substrate is not particularly limited. For example, a conventionally known method can be used.

Examples of the metallic film include those having conductivity and those having metallic luster. Can be

The metal colloid solution may be used as a coloring material in resin moldings such as optical materials, coating compositions, and the like, and may be used in antibacterial materials, catalysts, cosmetics, electromagnetic wave shields, and the like. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to only these Examples. “° / ₀ ” is% by mass.

Example 1

In 21 Kolben, 6.2 g of Dispervic 191 (manufactured by BIC CHEMICAL) and 280.2 g of ethanol were added. The Kolben was placed in a water bath and stirred at 50 ° C. until Dispersic 191 was dissolved. To this, 30.0 g of chloroauric acid dissolved in 280.2 g of ethanol was added with stirring, and the mixture was stirred at 50 ° C for 10 minutes. Next, when 32.4 g of dimethylaminoethanol was added, the solution instantaneously turned black and the solution temperature rose to 63 ° C. When the solution was allowed to stand and the temperature of the solution dropped to 50, stirring was continued for 2 hours while maintaining the temperature to obtain an ethanol solution of colloidal gold exhibiting a dark purple color.

Next, the ultrafiltration module AH P100 (made by Asahi Kasei Corporation; molecular weight cut-off: 50,000; number of membranes used: 400); a magnet pump; The stainless steel cup was connected with a silicon tube to form an ultrafiltration device. The ethanol solution of gold colloid was placed in a stainless steel cup, and 21 ethanol was added. Then, the pump was operated to perform ultrafiltration. When the filtrate from the module became 21 after about 40 minutes, 21 ethanol was added to the stainless steel cup. Thereafter, the filtrate was confirmed to have a conductivity of 30 S / cm or less, and concentrated until the amount of the mother liquor became 50 Om1.

Subsequently, a 50 Om1 stainless steel cup, an ultrafiltration module AH P001 (manufactured by Asahi Kasei Corporation; molecular weight cut-off: 500, number of membranes used: 100), a tube pump, and an aspirator An ultrafiltration device consisting of This stainless steel cup The mother liquor obtained above was added and concentrated to increase the solid concentration. When the mother liquor reached about 10 Om 1, the pump was stopped, and the concentration was terminated to obtain an ethanol solution of colloidal gold with a solid content of 30%. The average particle size of the colloidal gold particles in this solution obtained by observation with an electron microscope was 22 nm. Using TG-DTA (manufactured by Seiko Instrument), the content of gold in the solid content consisting of the colloidal gold particles and the polymer pigment dispersant was measured. , 90% by mass.

Drop 3 g of this colloidal gold ethanol / ray solution onto the center of a 10 cm square glass plate, and spin-coat with a spin coater at 400 rpm for the first step for 5 seconds and 600 rpm for the second step for 30 seconds. Then, a dark golden film was obtained. Subsequently, the plate was placed in an oven, dried at 150 ° C. for 10 minutes to remove the solvent, and then baked at 250 ° C. for 50 minutes to obtain a metal having a metallic luster of 0.7 / zm in film thickness. A functional film was obtained. The surface resistivity of this metallic film was measured using Loresta FP (manufactured by Mitsubishi Chemical Corporation) and found to be 0.08 Ω / port.

Example 2

The first ultrafiltration module was changed from AHP1010 to ACP1010 (Asahi Kasei Corporation; molecular weight cut off: 13000, 400 membranes used), and the same procedure was applied instead of ethanol added in the first ultrafiltration. Except that the amount of ion-exchanged water was used, the same treatment as in Example 1 was performed to obtain an aqueous solution of gold colloid having a solid content of 30%. The average particle size of the colloidal gold particles in this solution was 21 nm. Further, the content of gold in the solid content was measured using TG_DTA (manufactured by Seiko Instrument), and was found to be 90% by mass with respect to 70% by mass of the preparation.

Example 3

4.9 g of E FKA4550 (manufactured by EFKA Chemical Co., Ltd.), 12.1 g of ethanol, and 13.0 g of dimethylaminoethanol were placed in a 50 Om1 colben. The Kolben was placed in a water path and stirred at 50 ° C for about 10 minutes until EFKA4550 was dissolved. While stirring was continued, when 12.2 g of chloroauric acid dissolved in 12.1 g of ethanol was added, the solution turned black instantaneously and the temperature of the solution decreased to 58%. ° C. When the solution temperature was lowered to 50 ° C by leaving it as it was, stirring was continued for 2 hours while maintaining this temperature, and an ethanol solution of colloidal gold having a dark purple color was obtained.

Subsequently, an ultrafiltration apparatus including a 50 Om 1 stainless steel cup, an ultrafiltration module AHP0013 (Asahi Kasei Corporation; molecular weight cutoff 50,000, number of membranes used: 100), a tube pump, and an aspirator was assembled. The ethanol solution of the previously obtained colloidal gold was put into this stainless steel cup, and ultrafiltration was performed. After about 30 minutes, when the filtrate from the module reached 300 ml, 300 ml of ethanol was added to the stainless steel cup. After confirming that the conductivity of the filtrate was 30 μSZ cm or less, the mother liquor was concentrated to 5 Om 1 to obtain an ethanol solution of gold colloid having a solid content of 25%. The average particle size of the colloidal gold particles in this solution was 24 nm. Using TG-DTA (manufactured by Seiko Instruments), the content of gold in the solid content consisting of the colloidal gold particles and the polymeric pigment dispersant was measured. % By mass.

Example 4

In a 500 ml Kolben, add 4.6 g of Dispervic 184 (manufactured by BIC CHEMI), 11.2 g of ion-exchanged water, and 13.0 g of dimethylaminoethanol and stir at room temperature for about 10 minutes. did. While stirring, 12.0 g of chloroauric acid in which ion-exchanged water was dissolved in 12.1 g was added, and the solution turned black instantaneously, and the temperature of the solution changed from 20 ° C to 28 ° C. ° C. The stirring was continued for 2 hours to obtain an aqueous gold colloid solution having a dark bluish purple color.

Subsequently, an ultrafiltration apparatus comprising a 50 Om 1 stainless steel cup, an ultrafiltration module AHP0013 (Asahi Kasei Corporation; molecular weight cutoff 50,000, number of membranes used: 100), a tube pump, and an aspirator was assembled. The aqueous solution of the previously obtained colloidal gold was put into the stainless steel cup, and ultrafiltration was performed. About 30 minutes later, when the filtrate from the module reached 300 ml, 30 Om 1 of ion-exchanged water was added to the stainless steel cup. After confirming that the conductivity of the filtrate was 300 μS / cm or less, the mother liquor was concentrated to 5 Oml, and a gold colloid with a solid content of 25% was obtained. An ethanol solution was obtained. The average particle diameter of the colloidal gold particles in this solution was 25 nm. In addition, when the content of gold in the solid content composed of colloidal gold particles and a polymeric pigment dispersant was measured using TG-DTA (manufactured by Seiko Corporation), 70 mass of the charged material was measured. % Was 90% by mass.

Example 5

21 1 Kolben was charged with 14.0 g of Dispervic 190 (manufactured by BIC CHEMICAL), 294.3 g of 1 mo 1/1 nitric acid, and 294.3 g of ion-exchanged water. The Kolben was placed in a water bath and stirred at 50 ° C. until the Dispervic 190 was dissolved. To this, 50.0 g of silver nitrate obtained by dissolving 83.0 g of ion-exchanged water was added with stirring, and the mixture was stirred at 70 ° C. for 10 minutes. Next, when 131.0 g of dimethylaminoethanol was added, the liquid instantly turned black and the liquid temperature rose to 76 ° C. When the solution temperature was lowered to 70 ° C. by leaving it as it was, stirring was continued for 2 hours while maintaining this temperature, and an aqueous solution of silver colloid having a dark yellow color was obtained. This reaction solution was transferred to a poly bottle of 11 and allowed to stand in a constant temperature room at 60 ° C. for 18 hours. Next, an ultrafiltration module AHP100 (made by Asahi Kasei Corporation; molecular weight cut-off: 500,000 membranes: 400), a magnet pump, and a 31 stainless steel cup with a tube connection port at the bottom An ultrafiltration device was connected by a silicon tube. The reaction solution was allowed to stand for 18 hours in a constant temperature chamber at 60 ° C., placed in a stainless steel cup, and after adding 21 ion-exchanged water, the pump was operated to perform ultrafiltration. When the filtrate from the module became 21 after about 40 minutes, 21 ion-exchanged water was added to the stainless steel cup. After that, it was confirmed that the conductivity of the filtrate was less than 300 μSZ cm, and the concentration was performed until the amount of the mother liquor became 500 ml.

Subsequently, 50 Oml stainless steel cup containing mother liquor, ultrafiltration module AHP001 (Asahi Kasei Co., Ltd .; molecular weight cut-off 50,000, number of membranes used: 100), tube pump, and aspirator Was assembled in an ultrafiltration apparatus. The mother liquor obtained above was placed in this stainless steel cup, and concentrated to increase the solid content. When the mother liquor reached about 100 ml, the pump was stopped, and the concentration was terminated, whereby an aqueous solution of silver colloid having a solid content of 30% was obtained. Gold colloid particles in this solution The average particle size of the particles was 27 nm. Further, the content of silver in the solid content was measured using TG-DTA (manufactured by Seiko Instrument), and was found to be 90% by mass with respect to 85% by mass of the preparation.

Example 6

The first ultrafiltration module was changed from AHP1010 to ACP1010 (Asahi Kasei Corporation; molecular weight cut off: 13,000, membrane number: 400), and added in the first ultrafiltration The procedure was the same as in Example 5, except that the same amount of ethanol was used instead of the ion-exchanged water to obtain an aqueous solution of silver colloid having a solid content of 30%. The particle size was 27 nm, and the content of silver in the solid was measured using TG_DTA (manufactured by Seiko Instrument). Met.

When 3 g of this aqueous solution of silver colloid was dropped in the center of a 10 cm square glass plate and spin-coated with a spin coater under the conditions of 1st step 400 rpm for 5 seconds and 2nd step 600 r for 30 seconds, it became bluish. A silver film was obtained. Subsequently, the plate was placed in an oven, dried at 150 ° C for 10 minutes to remove the solvent, and then baked at 250 ° C for 50 minutes to obtain a metal with a metal luster of 0.5 μιη. A dermal membrane was obtained. The surface resistivity of this metallic film was measured using a Loresta FP (manufactured by Mitsubishi Chemical Corporation) and found to be 0.05 Ω.

Example 7

1.6 g, 1 mo 1/1 nitric acid (82.4 g), and ion-exchanged water (82.4 g) are added in this order to 50 Om1 kolben. The Kolben was placed in a water bath and stirred at 50 ° C. until Dispervik 192 was dissolved. 14.0 g of silver nitrate obtained by dissolving 247.25 g of ion-exchanged water was added thereto with stirring, followed by stirring at 70 ° C. for 10 minutes. Next, 36.7 g of dimethylaminoethanol was added. At this time, the liquid instantly turned black and the liquid temperature rose to 74 ° C. When the solution temperature was lowered to 70 ° C by leaving it as it was, stirring was continued for 2 hours while maintaining the temperature, and an aqueous solution of silver colloid having a blackish yellow color was obtained. The container containing the reaction solution was allowed to stand in a constant temperature chamber at 60 ° C. for 18 hours, and then the ultrafiltration module AHP 0013 (Asahi Kasei Co., Ltd .; molecular weight cut-off 50,000, membrane number used: 100), tube pump Ultrafiltration was performed by setting up an ultrafiltration device together with the aspirator and the aspirator. About 30 minutes later, when the filtrate from the module reached 300 ml, 300 ml of ion-exchanged water was added to the Kolben. After confirming that the conductivity of the filtrate became 300 μS / cm or less, the mother liquor was concentrated to 5 Oml to obtain an aqueous solution of silver colloid having a solid content of 25%. The average particle size of the silver colloid particles in this solution was 30 nm. Further, the content of silver in the solid content was measured using TG-DTA (manufactured by Seiko Instrument), and was found to be 90% by mass with respect to 85% by mass of the preparation.

Example 8

100 ml of an aqueous 0.1 ml silver nitrate solution acidified with nitric acid was placed in a beaker, and 5 g of Dispervic 190 (manufactured by BYK-Chemie) was added and dissolved. To this was added 5 ml of triethanolamine to obtain an aqueous solution of silver colloid which was rich and bright yellow. This solution was centrifuged at 3000 G for 30 minutes using a centrifuge to precipitate silver colloid particles. After removing the supernatant, an appropriate amount of water was added, and washing was performed by repeating the centrifugation under the same conditions three times as before to obtain a silver paste with a solid content of 85%.

This paste was diluted with isopropanol, and the solution diluted to 20% solid content was measured for the silver content in the solid content using TG-DTA (manufactured by Seiko Instruments). % Was 98% by mass. In Examples 1 to 8 using ultrafiltration or centrifugation, a metal colloid solution containing a higher concentration of metal colloid particles as compared with the charged amount was obtained. Also, in Example 1 and

In 6, the obtained metal colloid high-concentration solution could be suitably used for forming a film having high conductivity.

Example 9

In the same manner as in Example 1, except that 6.2 g of Dispervik 191 (manufactured by Big Chemical Co., Ltd.) was weighed to 21.5 g, a gold colloid ethanol having a solid content of 30% was produced in the same manner. A nore solution was obtained. Using TG-DTA (manufactured by Seiko Instruments), the content of gold in the solid content consisting of colloidal gold particles and a polymeric pigment dispersant was measured. Met.

Example 10

The first ultrafiltration module was changed from AHP 1010 to ACP 1010 (Asahi Kasei Corporation; molecular weight cut off 13,000, membrane number 400 used), and instead of ethanol added in the first ultrafiltration. Except that the same amount of ion-exchanged water was used, the treatment was performed in the same manner as in Example 1 to obtain an aqueous solution of gold colloid having a solid content of 30%. The average particle size of the colloidal gold particles in this solution was 21 nm. In addition, the content of gold in the solid content was measured using TG-DTA (manufactured by Seiko Instruments), and was found to be 55% by mass with respect to 40% by mass of the charged material. possibility

According to the production method of the present invention, a metal colloid high concentration solution having a high metal concentration can be obtained even when a large amount of a polymer pigment dispersant is used to ensure dispersion stability. The resulting metal colloid high-concentration solution is suitably used for a metallic coating having conductivity or metallic luster.

Claims

The scope of the claims

1. A method for producing a high-concentration metal colloid solution, comprising removing a part of the polymer pigment dispersant from the solution containing the metal colloid particles and the polymer pigment dispersant.

2. The method for producing a metal colloid high concentration solution according to claim 1, wherein the removal of a part of the polymer pigment dispersant is performed by centrifugation.

3. The method according to claim 2, wherein the centrifugation is performed at 100 G or more.

4. The method for producing a high-concentration metal colloid solution according to claim 1, wherein the removal of a part of the polymer pigment dispersant is performed by ultrafiltration.

5. The method for producing a high-concentration metal colloid solution according to claim 4, wherein the ultrafiltration uses a filtration membrane having a molecular weight cut-off of from 300 to 800.

6. The solution containing the metal colloid particles and the polymer pigment dispersant, wherein the solution is obtained by reducing a metal compound in the presence of the polymer pigment dispersant. The method for producing a metal colloid high concentration solution according to the above.

7. The metal concentration in the solid content of the solution containing the metal colloid particles and the polymer pigment dispersant is 85% by mass or less, and the metal concentration in the solid content of the metal colloid high concentration solution is 90 mass parts or more. 7. The method for producing a high-concentration metal colloid solution according to claim 1, 2, 3, 4, 5, or 6.

8. The method according to claim 1, wherein the difference in metal concentration in the solid content between the metal colloid high concentration solution and the solution containing the metal colloid particles and the polymer pigment dispersant is 10% by mass or more. 8. The method for producing a metal colloid high concentration solution according to 4, 5, 6, or 7.

9. A high-concentration metal colloid solution obtained by the method for producing a high-concentration metal colloid solution according to claim 1, 2, 3, 4, 5, 6, 7, or 8.

10. A film obtained by using the metal colloid high-concentration solution according to claim 9.