CN105164183A - Metal nanoparticle-protecting polymer and metal colloidal solution, and method for producing same - Google Patents

Abstract

The invention provides a metal nanoparticle-protected polymer, the metal nanoparticle-protected polymer includes a polyacetylalkyleneimine segment (A) and a hydrophilic segment (B) in the molecule, wherein the polyacetyl In the alkyleneimine segment (A), 5 to 100 mol% of the primary amines in the polyalkyleneimine are acetylated and 0 to 50 mol% of the secondary amines in the polyalkyleneimine are acetylated. The present invention also provides a method for producing a metal nanoparticle-protected polymer, a metal colloid solution and a method for preparing the metal colloid solution. The metal colloid solution includes a medium and a composite dispersed in the medium, and each composite contains metal nanoparticles. Protective polymer-protected metal nanoparticles.

Description

Metal nanoparticle protective polymer and metal colloid solutions and methods for their manufacture

technical field

The present invention relates to a metal colloid solution and a method for producing the metal colloid solution, the metal colloid solution uses a polymer as a protective agent for metal nanoparticles, and the polymer is a polyalkyleneimine segment comprising acetylation and a hydrophilic The polymer of the sexual segment, or the polymer that also contains the hydrophobic segment in addition to the above two segments. The present invention also relates to the above-mentioned polymers and methods of making the polymers.

Background technique

Metal nanoparticles are a kind of nanoparticles with a particle size ranging from 1 to hundreds of nanometers and a relatively large specific surface area. Metal nanoparticles having such properties attract attention from various fields, and are highly expected to be used in electronic materials, catalysts, magnetic materials, optical materials, various sensors, coloring materials, and medical inspections.

Printed wiring boards and semiconductors are mainly manufactured by a photolithography process that includes a series of complicated manufacturing steps. In this context, fabrication techniques for printable electronics stand out. Manufacturing techniques of printable electronic devices include preparing an ink composition by dispersing recently developed metal nanoparticles in a medium, forming a pattern by printing using the ink composition, and assembling the pattern in the device.

The technology is called printed electronics (printedelectronics). Printed electronics technology makes it possible to realize roll-to-roll mass production of electronic circuit patterns and semiconductor elements, and brings economic efficiency since the technology is suitable for on-demand manufacturing, process simplification, and resource saving. It is also expected that the technology will be ready for low-cost manufacturing processes for display devices, light emitting devices, IC tags (RFID) and the like. Conductive material inks used in printed electronics may contain metal nanoparticles such as gold, silver, platinum, copper, etc. The development of silver nanoparticles and inks containing silver nanoparticles was pioneered for economical reasons and ease of handling.

Silver in the form of nanoparticles exhibits a considerable specific surface area and increased surface energy compared to bulk silver. Silver nanoparticles have a strong tendency to fuse with each other to lower the surface energy. As a result, the particles fuse to each other at temperatures well below the melting point of bulk silver. On the one hand, this phenomenon, known as the quantum size effect (Kubo effect), exhibits the advantage of using silver nanoparticles as a conductive material. On the other hand, since the metal nanoparticles have a strong tendency to fuse with each other, the stability of the metal nanoparticles is impaired and the storage stability is lowered. In order to stabilize the metal nanoparticles, the metal nanoparticles need to be protected by a protecting agent against fusion.

Typically, nanomaterials (typically compounds with nanoscale dimensions) are manufactured through specialized processes that tend to be expensive due to their size. This inhibits the popularity of nanomaterials. In order to manufacture metal nanoparticles at low cost, there is an advantage in a liquid phase reduction process that does not require special equipment such as a vacuum processing chamber. The liquid phase reduction process is a process for obtaining metal nanoparticles by reacting a metal compound with a reducing agent in a solvent. According to known techniques, the reduction process is carried out in the presence of compounds called dispersion stabilizers or protective agents in order to control the shape and particle size of metal nanoparticles to be produced and to achieve a stable dispersion state. Protective agents are mostly polymer compounds with functional groups capable of coordinating with metal particles (such as tertiary amino groups, quaternary ammonium groups, heterocyclic groups with basic nitrogen atoms, hydroxyl groups, or carboxyl groups) (for example, refer to Patent Document 1).

As described above, in order to manufacture metal nanoparticles that can be expected to undergo desired low-temperature fusion, a suitable protective agent that controls the shape and particle size of the metal nanoparticles and stabilizes dispersion is used. However, the preservative acts as a resistive component to the bulk metal, reducing electrical conductivity. Depending on the amount of protective agent used, it may not be possible to exhibit the desired low-temperature sintering properties (the specific resistance of the film is on the order of 10 ^-6 ohm-cm. Conductive ink films of nanoparticles). From the viewpoint of designing conductive materials, preservatives are required to exhibit the ability to produce small particles, the ability to disperse these particles stably, and the ability to quickly leave from the particle surface during sintering so as not to inhibit fusion between metal nanoparticles. From the viewpoint of producing metal nanoparticles, the protective agent is required to exhibit the ability to facilitate the purification and separation of the produced metal nanoparticles. Preservatives preferably exhibit all of these capabilities. Examples of protective agents disclosed so far include: commercially available polymer pigment dispersants such as Solsperse (trademark, manufactured by Zeneca) and FLOWLEN (trademark, manufactured by Kyoeisha Chemical Co., Ltd.); A polymer with a neutral group (amine) and more than two solvating segments, and a copolymer with a polyethyleneimine segment and a polyethylene oxide segment. However, these dispersants rarely achieve all the desired capabilities described above, requiring further improvement (for example, refer to Patent Documents 2 to 4).

Citation

patent documents

Patent Document 1: Japanese Unexamined Patent Application Publication No. 2004-346429

Patent Document 2: Japanese Unexamined Patent Application Publication No. 11-080647

Patent Document 3: Japanese Unexamined Patent Application Publication No. 2006-328472

Patent Document 4: Japanese Unexamined Patent Application Publication No. 2008-037884

Contents of the invention

technical problem

The object of the present invention is to provide a metal nanoparticle-protected polymer, which is intentionally adjusted and endowed with various properties, such as the ability to control metal nanoparticles, high dispersion stability, good low-temperature sinterability and refining and separating metal nanoparticles ease in order to demonstrate more practical conductivity. Moreover, a metal colloid solution and a method for manufacturing the metal nanoparticle protective polymer and the metal colloid solution are also provided.

solution

The inventors of the present invention have disclosed (see Patent Document 4) that the following binary system polymer and ternary system polymer can be used to produce metal nanoparticles. The binary system polymer contains polyalkyleneimine of polyethyleneimine The segment is connected with the hydrophilic segment containing polyoxyalkylene chain, and the hydrophobic segment (such as epoxy resin) in the ternary system polymer is connected with the aforementioned binary system polymer. However, according to the technique disclosed in Patent Document 4, the above properties are not sufficiently realized. Based on further research, the inventors found that it is effective to use a polymer in which the nitrogen atom in the polyalkyleneimine segment is acetylated, leading to the present invention.

In other words, the present invention provides a metal nanoparticle-protecting polymer, which includes a polyacetylalkyleneimine segment (A) and a hydrophilic segment (B) in the molecule, and the polyacetylalkyleneimine In the segment (A), 5-100 mol% of the primary amines in the polyalkyleneimine are acetylated, and 0-50 mol% of the secondary amines in the polyalkyleneimine are acetylated. The present invention also provides a method for producing a metal nanoparticle-protected polymer, a metal colloid solution comprising a composite containing metal nanoparticles dispersed in a medium (the composite is prepared by using a metal nanoparticle-protected polymer as a protective agent), And the manufacture method of metal colloid solution.

Beneficial Effects of the Invention

The metal colloid solution obtained in the present invention exhibits good low-temperature sinterability. Since the protective polymer used in the present invention is easily detached from the surface of metal nanoparticles at low temperature, the film obtained by firing the metal colloid solution at low temperature exhibits good electrical conductivity. Further, regarding the metal nanoparticles obtained in the presence of this specific protective polymer, the size is sufficiently small and monodisperse, and the particle size distribution is narrow. Therefore, storage stability is also high. This is because the acetylenimine structural unit in the protective polymer can well protect the metal nanoparticles, and the hydrophilic segment or hydrophobic segment in the polymer enables the particles to disperse in the medium. Thereby, the dispersion stability of the dispersion is not impaired and the dispersion maintains a stable dispersion state in the solvent for a long period of time.

In the present invention, when the metal colloid solution is produced, the metal nanoparticles are obtained by reduction, and in the subsequent purification and separation steps for removing impurities, by a simple operation such as adding a poor solvent to the dispersion of the complex, by The complex composed of metal nanoparticles and protective polymer is easily settled and separated. This is achieved due to the strong association of the protective polymer. This method is industrially advantageous since complicated steps and precise condition setting are rarely required.

In addition, the metal nanoparticles in the metal colloid solution obtained in the present invention have large specific surface area, high surface energy and plasmon absorption, which are characteristics of metal nanoparticles. In addition to these characteristics, dispersion stability and storage stability can be effectively exhibited because the polymer dispersion is a self-assembled type. Therefore, the metal colloid solution has various chemical properties, electrical properties, and magnetic properties required for conductive pastes, etc., and can be used in a wide range of fields, such as catalysts, electronic materials, magnetic materials, optical materials, various sensors, coloring, etc. Materials and medical inspection purposes.

Detailed ways

The metal nanoparticle protection polymer of the present invention is a polymer compound having a hydrophilic segment (B) and a polyacetylenimine segment (A), and in the polyacetylenimine segment (A) 5-100mol% of primary amines and 0-50mol% of secondary amines in polyalkyleneimine are acetylated; or, the metal nanoparticle protection polymer of the present invention has polyacetylalkyleneimine segment (A ), a polymer compound of a hydrophilic segment (B) and a hydrophobic segment (C). A dispersion of metal nanoparticles protected by a protective polymer (metal colloid solution) having this structure has high dispersion stability and good conductive properties, and exhibits the properties of a metal-containing functional dispersion derived from metal nanoparticles. Various functions such as coloring, catalysis and electrical functions.

The polyacetylalkyleneimine segments (A) in the protected polymers of the present invention are acetylated to a specific degree. Since the acetylalkyleneimine unit in the segment can form a coordination bond with a metal or a metal ion, the polyacetylalkyleneimine segment (A) is a segment capable of immobilizing metal as nanoparticles. When the metal nanoparticles obtained in the present invention are protected with a protective polymer to form a complex, and the complex is produced and stored in a hydrophilic solvent, due to the presence of polyacetylene that exhibits hydrophilicity in the solvent imine segment (A) and hydrophilic segment (B), so the obtained metal colloid solution can exhibit excellent dispersion stability and storage stability.

From an industrial manufacturing point of view, simple purification and isolation methods of complexes prepared by protecting metal nanoparticles with protective polymers by dissolving or dispersing metal in the medium are key processes Compounds and the reduction of metal compounds in the medium. The purification and separation method preferably includes settling by adding a poor solvent such as acetone to the reacted solution. The acetylalkyleneimine units in the protective polymer of the present invention have high polarity, thereby promoting rapid association of complexes containing metal nanoparticles. Therefore, sedimentation tends to occur simultaneously with the formation of large aggregates of associated particles.

A metal colloid solution, which is a dispersion liquid containing a metal nanoparticle complex, or a conductive material obtained by using the metal colloid solution to form a conductive ink is printed or coated on a substrate. In the subsequent sintering step, the acetylalkyleneimine units in the protective polymers were easily detached from the surface of the metal nanoparticles even at low temperatures due to the weak coordination bonds between the units and the metal. As a result, good low-temperature sinterability was exhibited.

The particle size of the dispersion (composite) in the metal colloid solution of the present invention not only depends on the molecular weight of the protective polymer used and the degree of polymerization of the polyacetylenimine segment (A), but also depends on the protective polymer The structure and composition ratio of the constituent components, that is, the polyacetylalkylene imine segment (A), the following hydrophilic segment (B) and the following hydrophobic segment (C).

The degree of polymerization of the polyacetylalkyleneimine segment (A) is not particularly limited. In the case of too low polymerization, the protective polymer may not exhibit sufficient ability to protect the metal nanoparticles. In the case where the polymerization is too high, the size of the composite particle composed of the metal nanoparticles and the protective polymer may become too large, thereby reducing the storage stability. Therefore, in order to improve the fixing ability of metal nanoparticles and prevent the generation of huge dispersed particles, the number of alkylene imine units (polymerization degree) in the polyacetylalkylene imine segment (A) is usually in the range of 1 to 10,000, Preferably it is the range of 5-2,500, More preferably, it is the range of 5-300.

The polyacetylalkyleneimine segment (A) can be easily obtained by acetylating the alkyleneimine moiety in the precursor structure as the polyalkyleneimine segment. In particular, the polyacetylalkyleneimine segment (A) can be obtained by reacting with an acetylating agent. The segments composed of polyalkyleneimines may be any commercially available or synthesized segments. From the viewpoint of industrial availability, the segment is preferably composed of branched polyethyleneimine or branched polypropyleneimine, more preferably composed of branched polyethyleneimine.

In the case of using a hydrophilic solvent such as water to prepare a metal colloid solution, the hydrophilic segment (B) in the protective polymer of the present invention exhibits high compatibility with the solvent and maintains storage stability of the colloid solution. In the case of using a hydrophobic solvent, the hydrophilic segment (B) having a strong intramolecular or intermolecular association contributes to the formation of the core of the dispersed particles. The degree of polymerization of the hydrophilic segment (B) is not particularly limited. In the case of using a hydrophilic solvent, the storage stability decreases when the polymerization is too low, and aggregation may occur when the polymerization is too high. When using a hydrophobic solvent, when the polymerization of the hydrophilic segment (B) is too low, the association force between dispersed particles becomes insufficient, and when the polymerization is too high, compatibility with the solvent cannot be maintained. From these viewpoints, the degree of polymerization of the hydrophilic segment (B) is usually 1 to 10,000, preferably 3 to 3,000, and more preferably 5 to 1,000 based on easiness of production. When the hydrophilic segment is a polyoxyalkylene chain, the degree of polymerization is particularly preferably 5-500.

The hydrophilic segment (B) may be any commercially available or synthesized segment composed of a hydrophilic polymer chain. When using a hydrophilic solvent, the hydrophilic segment (B) is preferably composed of a nonionic polymer because a highly stable colloidal solution can be obtained.

Examples of the hydrophilic segment (B) include polyoxyalkylene chains (such as polyethylene oxide chains and polypropylene oxide chains), polymer chains composed of polyvinyl alcohols (such as polyvinyl alcohol and partially saponified polyvinyl alcohol) , a polymer chain composed of water-soluble poly(meth)acrylates such as polyhydroxyethylacrylate, polyhydroxyethylmethacrylate, dimethylaminoethylacrylate, and dimethylaminoethylmethacrylate , polyacylalkyleneimine chains containing hydrophilic substituents (such as polyacetylethyleneimine, polyacetylpropyleneimine, polypropionylethyleneimine, and polypropionylpropyleneimine), and polyacrylamides (such as Polymer chains composed of polyacrylamide, polyisopropylacrylamide and polyvinylpyrrolidone). Among them, a polyoxyalkylene chain is preferable because a highly stable colloid solution can be obtained and industrial availability is high.

In the present invention, the protective polymer may further contain a hydrophobic segment (C). In particular, when an organic solvent is used as a medium for the metal colloid solution, it is preferable to use a polymer containing a hydrophobic segment (C) as a protective agent.

The hydrophobic segment (C) may be any commercially available or synthesized segment consisting of residues of hydrophobic compounds. Examples of the hydrophobic segment (C) include segments composed of residues of polymers and residues of resins, such as: polystyrenes such as polystyrene, polymethylstyrene, poly Chloromethylstyrene and polybromomethylstyrene, water-soluble poly(meth)acrylates such as polymethylacrylate, polymethylmethacrylate, poly(2-ethylhexylacrylate) and poly(methacrylate) 2-ethylhexyl acrylate), polyacylalkyleneimides containing hydrophobic substituents, such as polybenzoylvinylimide, polybenzoylacrylimide, poly(meth)acryloylvinylidene Amines, poly(meth)acryloimide, poly(N-(3-(perfluorooctyl)propionyl)ethyleneimine), and poly(N-(3-(perfluorooctyl)propionyl) propyleneimine); residues of resins such as epoxy, polyurethane and polycarbonate. The hydrophobic segment (C) may consist of the residue of a single compound or of a compound obtained by previously reacting two or more different types of compounds. The hydrophobic segment (C) preferably has a structure derived from an epoxy resin, more preferably a structure derived from a bisphenol A type epoxy resin, because the protective polymer can be easily synthesized industrially and the metal colloid thus obtained The solutions exhibit high adhesion to substrates when printed or coated.

The degree of polymerization of the hydrophobic segment (C) is not particularly limited, if the hydrophobic segment (C) is polystyrene, poly(meth)acrylate, polyacylalkyleneimide containing hydrophobic substituents, etc., then Usually, it is 1-10,000, Preferably it is 3-3,000, More preferably, it is 10-1,000. When the hydrophobic segment (C) is composed of residues of resin (such as epoxy resin, polyurethane, polycarbonate, etc.), the degree of polymerization is usually 1-50, preferably 1-30, more preferably 1-20.

The metal nanoparticle-protected polymer of the present invention can be produced by reacting an acetylating agent with a precursor compound (I) having a polyalkylene imine segment and a hydrophilic segment (B ), or a compound having a polyalkyleneimine segment, a hydrophilic segment (B) and a hydrophobic segment (C). Alternatively, in the reaction for preparing the precursor compound (I) from the polyalkyleneimine segment and the hydrophilic segment (B), an acetylating agent may be used. According to any of these methods, the designed protective polymer can be easily obtained. The process disclosed in Patent Document 4 and Japanese Unexamined Patent Application Publication No. 2006-213887 can be directly used to produce the precursor compound (I).

After the precursor compound (I) is obtained, the nitrogen atoms of the primary and/or secondary amines in the polyalkyleneimine chain segment are acetylated. Alternatively, in the process of producing the precursor compound (I) by using the polyalkyleneimine segment and the hydrophilic segment (B), the primary amine and/or the secondary amine in the polyalkyleneimine segment Acetylation of the nitrogen atom. The acetylation reaction is carried out by adding an acetylating agent having an acetyl structure (CH ₃ -CO-).

A general-purpose industrial acetylating agent can be used as the acetylating agent. Examples of acetylating agents include: acetic anhydride, acetic acid, dimethylacetamide, ethyl acetate and chloroacetic acid. Among these acetylating agents, acetic anhydride, acetic acid, and dimethylacetamide are particularly preferred from the viewpoint of availability and ease of handling.

When the polyalkyleneimine segment is derived from a branched polyalkyleneimine compound, primary, secondary, and tertiary amines are contained uniformly or irregularly. When the polyalkyleneimine segment is reacted with any of the acetylating agents described above, one acetyl oxygen is provided for each nitrogen atom in the primary and/or secondary amine, while the tertiary amine remains unacetylated. In other words, the acetylation reaction occurs with primary and secondary amines that are quantitatively more reactive with the acetylating agent used. The acetylation ratio of the acetylation reaction was studied based on the acetylation ratio of primary and secondary amines. As a result, it was found that when 5 to 100 mol% of the primary amines in the polyalkyleneimine segment and 0 to 50 mol% of the secondary amines in the polyalkyleneimine segment were acetylated, a compound with good electrical conductivity and dispersion stability was obtained. As well as protective polymers with the ability to facilitate purification and separation.

As described above, the acetylenimine unit has a weaker coordination bond with the metal than the alkylenimine unit, so the acetylenimine unit is smoothly detached from the surface of the metal nanoparticles even at low temperatures. , as a result, exhibited good low-temperature sinterability. However, the resulting metal nanoparticle-protected polymer has lower dispersion stability (ability to stabilize metal nanoparticles) than polymers formed using alkylene imine units. Further, dispersion stability is reduced by stronger association force. In other words, dispersion stability and low-temperature sinterability are in a trade-off relationship. The above range of acetylation is limited from the viewpoint of the storage stability of the obtained metal colloid solution and the low-temperature sinterability of the coating film formed from the metal colloid solution.

The metal nanoparticle-protecting polymer of the present invention contains a hydrophilic segment (B) in addition to the polyacetylalkyleneimine segment (A) capable of stabilizing metal nanoparticles, and optionally contains a hydrophobic segment (C). As mentioned above, the hydrophilic segment (B) exhibits strong association in hydrophobic solvents and high compatibility with hydrophilic solvents, while the hydrophobic segment (C) exhibits Strong association, and high compatibility with hydrophobic solvents. Further, it is presumed that when the hydrophobic segment (C) contains an aromatic ring, π electrons in the aromatic ring interact with the metal to contribute to the stabilization of the metal nanoparticles.

The ratio of the number of moles of the polymer that constitutes the chain of polyacetylalkyleneimine segment (A) to the number of moles of the polymer that constitutes the chain of hydrophilic segment (B), that is, the molar ratio (A):(B) , there is no particular restriction. From the viewpoint of dispersion stability and storage stability of the obtained metal colloid solution, the ratio is usually in the range of 1:(1 to 100), preferably in the range of 1:(1 to 30). When the protective polymer also contains a hydrophobic segment (C), from the viewpoint of the dispersion stability and storage stability of the obtained metal colloid solution, the polymerization of the polyacetylenimine segment (A) chain The ratio of the number of moles of the substance, the number of moles of the polymer that constitutes the hydrophilic segment (B) chain, and the number of moles of the polymer that constitutes the chain of the hydrophobic segment (C), that is, the molar ratio (A):(B ):(C) is usually within the range of 1:(1-100):(1-100), preferably within the range of 1:(1-30):(1-30). The weight average molecular weight of the metal nanoparticle-protecting polymer of the present invention is preferably in the range of 1,000 to 500,000, more preferably in the range of 1,000 to 100,000.

The protective polymer of the present invention is dispersed or dispersed in various media for the manufacture of metal colloid solutions. The material used as the medium is not particularly limited, and the dispersion may be an oil/water (O/W) system or a water/oil (W/O) system. The medium can be selected according to the manufacturing process of the metal colloid solution and/or the use of the metal colloid solution. For example, a hydrophilic solvent, a hydrophobic solvent, a mixed solvent containing hydrophilic and hydrophobic solvents, or a mixed solvent containing other solvents in addition to the aforementioned solvents as described below can be selected. When using a mixed solvent, the amount of the hydrophilic solvent is adjusted to be greater than that of the hydrophobic solvent for the O/W system, and the amount of the hydrophobic solvent is adjusted to be greater than the hydrophilic solvent for the W/O system. The mixing ratio depends on the type of solvent used, so the mixing ratio is not particularly limited. Generally, for an O/W system, it is preferable that the volume of the hydrophilic solvent is more than 5 times larger than that of the hydrophobic solvent, and for a W/O system, it is preferable that the volume of the hydrophobic solvent is more than 5 times larger than that of the hydrophilic solvent.

Examples of hydrophilic solvents include methanol, ethanol, isopropanol, tetrahydrofuran, acetone, dimethylacetamide, dimethylformamide, ethylene glycol, propylene glycol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethyl Glyme, Propylene Glycol Dimethyl Ether, Dimethyl Sulfoxide, Dioxirane, and N-Methylpyrrolidone. These can be used alone or in combination.

Examples of hydrophobic solvents include hexane, cyclohexane, ethyl acetate, butanol, methylene chloride, chloroform, chlorobenzene, nitrobenzene, methoxybenzene, toluene, and xylene. These can be used alone or in combination.

Examples of other solvents that can be used in admixture with hydrophilic or hydrophobic solvents include ethyl acetate, propyl acetate, butyl acetate, isobutyl acetate, ethylene glycol monomethyl ether acetate, and propylene glycol monomethyl ether ethyl acetate. esters.

The metal nanoparticle protecting polymer can be dispersed in the medium by any method. Usually, the metal nanoparticle protecting polymer can be easily dispersed by keeping the polymer standing still or stirring at room temperature. Sonication or heat treatment may be performed if desired. When the protective polymer is not easily compatible with the medium due to its crystallinity, etc., the protective polymer can be dissolved or swollen in a small amount of good solvent, and then dispersed in the dispersion medium. In this process, ultrasonic treatment or heat treatment is effective.

A mixture of a hydrophilic solvent and a hydrophobic solvent can be prepared by any mixing method, mixing order and the like. Since the compatibility of the protective polymer with various solvents and the dispersibility of the protective polymer differ depending on the type, composition and other factors of the protective polymer, the solvent mixing ratio, solvent mixing order, solvent Mixing method, mixing conditions, etc.

According to the method for producing a metal colloid solution of the present invention, metal ions are reduced in a solution or dispersion of a protective polymer to form metal nanoparticles. The source of metal ions can be a metal salt or a solution of metal ions. The source of metal ions can be any water-soluble metal compound, for example, a salt of a metal cation with an acid-based anion or a metal-containing acid-based anion. For example, metal ions having metal species such as transition metals are preferably used.

Regardless of whether the transition metal ion is a transition metal cation (M ⁿ⁺ ) or an anion (ML _x ⁿ⁻ ) composed of halogen bonds, the transition metal ion can coordinate smoothly to form a complex. In the present specification, a transition metal refers to a transition metal element of Group 4 to Group 12 and a period of 4 to 6 in the periodic table.

Examples of transition metal cations include transition metal cations (M ⁿ⁺ ), such as monovalent, divalent, trivalent or tetravalent cations of Cr, Co, Ni, Cu, Pd, Ag, Pt, Au, and the like. The counteranion of the metal cation may be Cl, _NO3 , _SO4 or an organic anion of a carboxylic acid.

Anions formed by coordination of metals and halogens, such as AgNO ₃ , AuCl ₄ , PtCl ₄ , or CuF ₆ , which contain metal anions (ML _x ⁿ⁻ ), can also coordinate smoothly to form complexes.

Among these metal ions, silver, gold, and platinum ions are preferable because they spontaneously reduce to nonionic metal nanoparticles at room temperature or under heating. In the case of using the obtained metal colloid solution as a conductive material, silver ions are preferably used in order to develop conductivity and prevent oxidation of a coating film obtained by printing or coating the metal colloid solution.

The number of metal types contained may be two or more. In this case, multiple metal salts or ions are added simultaneously or separately, so that different types of metal ions undergo reduction reactions in the medium to generate different types of metal particles. Thus, a colloidal solution containing multiple metals can be obtained.

In the present invention, a reducing agent can be used to reduce metal ions.

The reducing agent can be any kind of reducing agent. It can be selected based on the use of the obtained metal colloid solution, the type of metal contained, and the like. Examples of reducing agents include hydrogen, boron compounds such as sodium borohydride and ammonium borohydride, alcohols such as methanol, ethanol, propanol, isopropanol, ethylene glycol and propylene glycol, aldehydes such as formaldehyde, acetaldehyde and propionaldehyde, acids Such as ascorbic acid, citric acid and sodium citrate, amines such as propylamine, butylamine, diethylamine, dipropylamine, dimethylethylamine, triethylamine, ethylenediamine, triethylenetetramine, methylaminoethanol, Amino ethanol and triethanolamine, and hydrazines such as hydrazine and hydrazine carbonate. Among them, sodium borohydride, ascorbic acid, sodium citrate, methylaminoethanol and dimethylaminoethanol are preferred because of high industrial availability and easy handling.

In the method for producing the metal colloid solution of the present invention, the ratio of the metal ion source to the protective polymer is not particularly limited. For example, when the total number of nitrogen atoms constituting the polyacetylalkyleneimine segment in the protective polymer is set to 100 mol, the amount of the metal is usually in the range of 1 to 20,000 mol, preferably in the range of 1 to 10,000 mol, More preferably, it exists in the range of 50-7,000 mol.

In the method for producing the metal colloid solution of the present invention, the medium in which the protective polymer is dispersed or dissolved may be mixed with the metal salt or the ion solution by any method. For example, the metal salt or ionic solution can be added to the medium in which the protective polymer is dispersed or dissolved, or vice versa, or the protective polymer and the metal salt or ionic solution can be simultaneously supplied to different containers and mixed . The mixing method is not particularly limited and may be stirring.

The reducing agent can be added by any method. For example, the reducing agent may be directly added, or may be mixed after dissolving or dispersing the reducing agent in an aqueous solution or another solvent. The order of adding the reducing agent is not particularly limited. The reducing agent may be added to the dispersion or solution of the protective polymer in advance, or the reducing agent may be added to the protective polymer together with the metal salt or ion solution. Alternatively, the solution or dispersion of the protective polymer may be mixed with the metal salt or ion solution, and then a reducing agent may be added thereto after several days or weeks.

When adding the metal salt or its ion solution used in the production method of the present invention to the medium in which the protective polymer is dispersed or dissolved, it is preferable to add the metal directly or in the form of an aqueous solution regardless of whether the system is O/W or W/O. salt or its ionic solution. When the metal ion is silver, gold, palladium, platinum, etc., the metal ion coordinates with the acetylenimine unit in the polymer, and then spontaneously reduces at room temperature or under heating. Therefore, by keeping the metal ions still or stirring the metal ions at room temperature or under heating, metal nanoparticles and a metal colloid solution that is a dispersion of a complex of metal nanoparticles protected by a protective polymer can be obtained. However, in order to efficiently reduce metal ions, it is preferable to use a reducing agent as described above, and the metal colloid solution can be obtained by keeping ions still or stirring ions at room temperature or under heating. In this process, it is preferable to use the reducing agent directly or prepare it into an aqueous solution in advance. The temperature at which the heating is performed varies depending, for example, on the type of protective polymer and the type of metal, medium, reducing agent used. Generally, the temperature is 100°C or lower, preferably 80°C or lower.

As a result of the reduction of metal ions as described above, metal nanoparticles are precipitated, while the surface of these particles is protected by a protective polymer which stabilizes the particles. The reduced solution contains impurities (such as reducing agents, counter ions of metal ions, and protective polymers that do not participate in the protection of metal nanoparticles), and thus, cannot function sufficiently as a conductive material. Therefore, a refining step for removing impurities is required. Since the protective polymer of the present invention has high protective performance, a poor solvent can be added to the solution after the reaction to effectively settle the complex composed of metal nanoparticles protected by the protective polymer. The settled complex can be concentrated or separated by centrifugation or the like. After concentration, an appropriate medium is added to control the non-volatile components (concentration) to suit the use of the metal colloid solution, and the resulting product is used for various uses.

The content of metal nanoparticles in the metal colloid solution obtained in the present invention is not particularly limited. However, if the content is too low, the properties of the metal nanoparticles in the colloidal solution cannot be fully exhibited. If the content is high or high, the relative weight of the metal nanoparticles in the colloidal solution increases, and because the balance between the excessive relative weight of the metal nanoparticles and the dispersion ability of the protective polymer can be lost, the colloidal solution can be expected Stability deteriorates. Further, from the viewpoint of protecting the reducing ability and coordination ability of the acetylenimine unit in the polymer, the non-volatile component content of the metal colloid solution is preferably in the range of 10 to 80% by mass, more preferably in the range of 20 to 80% by mass. 70% by mass. In order to exhibit sufficient conductivity using the colloidal solution as the conductive material, the metal nanoparticle content in the nonvolatile matter is preferably 93% by mass or more, more preferably 95% by mass or more.

The diameter of the metal nanoparticles contained in the nonvolatile matter in the metal colloid solution obtained in the present invention is not particularly limited. In order for the metal colloid solution to exhibit high dispersion stability, the metal nanoparticles are preferably fine particles with a particle diameter of 1-70 nm, more preferably 5-50 nm in particle diameter.

In general, metal nanoparticles having a size of several tens of nanometers have unique optical absorption caused by surface plasmon excitation that differs depending on the type of metal. Therefore, whether or not the metal exists in the form of nanoscale particles in the solution can be confirmed by measuring the plasmon absorption of the metal colloid solution obtained in the present invention. Further, by using a transmission electron microscope (TEM) image of a film obtained by casting the solution, the average particle diameter and distribution width can be determined.

The metal colloid solution obtained in the present invention maintains stable dispersion for a long period of time in all types of media, and thus its use is not particularly limited. Metal colloid solutions find use in various fields including catalysts, electronic materials, magnetic materials, optical materials, various sensors, coloring materials, and medical inspection uses. Since the kinds of metals and their desired content ratios can also be easily adjusted, desired effects for their use can be effectively exhibited. Further, since the solution maintains stable dispersion for a long period of time, the solution can withstand long-term use and long-term storage, making the solution very useful. Further, with regard to the production method of the metal colloid solution according to the present invention, complicated steps and precise condition setting are not required, and thus have great advantages in industrial methods.

Example

Now, the present invention will be described in further detail by examples, but these examples do not limit the scope of the present invention. "%" means "% by mass" unless otherwise specified.

The instruments and measuring methods adopted in the following examples are as follows:

¹ H-NMR: AL300 manufactured by JEOL Ltd., 300 Hz

Particle size measurement: FPAR-1000 manufactured by Otsuka Electronics Co., Ltd.

Plasmon absorption spectrum: UV-3500 manufactured by Hitachi, Ltd.

Confirmation of the structure of the protected polymer by ¹ H-NMR

About 3 mL of the protected polymer solution was concentrated and dried thoroughly under reduced pressure. The residue is dissolved in about 0.8mL of NMR measurement solvent (such as deuterated chloroform containing 0.03% tetramethylsilane), the resulting solution is placed in an NMR measurement sample glass tube with an outer diameter of 5mm, and a nuclear magnetic resonance absorption spectrometer is used. ¹ H-NMR spectrum was obtained by JEOLJNM-LA300. Chemical shift δ is based on tetramethylsilane as a standard substance.

Particle Size Measurement by Dynamic Light Scattering

Part of the metal colloid solution was diluted with purified water, and the particle size distribution and average particle size were determined with a FPAR-1000 Concentrated System Particle Analyzer manufactured by Otsuka Electronics Co., Ltd.

Metal content measurement in non-volatiles by thermogravimetric analysis

About 1 mL of the metal colloid solution was placed in a glass vial, and concentrated by heating on a boiling water bath under nitrogen flow. The residue was further vacuum-dried at 50° C. for 8 hours to obtain non-volatile matter. To an aluminum pan for thermogravimetric analysis, add accurately weighed 2-10 mg of non-volatile matter. The aluminum plate was mounted on an EXSTARTG/DTA6300 thermogravimetric analysis/differential thermal analyzer (manufactured by Seiko Instruments Co., Ltd.), and was heated from room temperature to 500°C at a rate of 10°C per minute under the condition of air flow, to measure the temperature due to heating. resulting in weight loss. The silver content in the non-volatile matter is calculated by the following equation:

Metal content (%) = 100 – weight loss (%)

Measurement of resistivity of metal thin films obtained from metal colloid solutions

About 0.5 mL of the metal colloid solution was dropped on the top of a clean 2.5×5 cm glass plate, and a No. 8 coating rod was used to form a coating film. After the coating film was air-dried, it was heated at 125° C. and 180° C. for 30 minutes in a hot air dryer to form a baked coating film. The thickness of the fired coating film was measured with an Optelics C130 true-color confocal microscope (manufactured by Lasertec Co., Ltd.), in accordance with Japanese Industrial Standards (JIS) K7194 "Test method for resistivity of conductive plastics using a four-point probe arrangement method", using Loresta-EPMCP - T360 low resistivity tester (manufactured by Mitsubishi Chemical Corporation) to measure surface resistivity (ohm per square). Under the above conditions, the thickness of the coating film is generally kept constant at 0.3 microns, and the volume resistivity (ohm-cm) is calculated based on the thickness and surface resistivity (ohm per square) by the following equation: volume resistivity (ohm-cm) = surface resistivity (ohm per square) x thickness (cm)

[Synthesis Example 1: Synthesis of Tosylated Polyethylene Glycol Monomethyl Ether (PEGM)]

Under a nitrogen atmosphere, a chloroform solution (30 mL) containing 9.6 g (50.0 mmol) of p-toluenesulfonyl chloride was added dropwise to a solution containing 20.0 g (10.0 mmol) of methoxypolyethylene dichloride under stirring and ice cooling for 30 minutes. Alcohol (Mn=2,000), 8.0g (100.0mmol) pyridine and 20mL chloroform mixed solution. After completion of the dropwise addition, the resulting mixture was further stirred at 40° C. for 4 hours. After the reaction was completed, 50 mL of chloroform was added to dilute the reaction solution. Then, the diluted reaction solution was successively washed with 100 mL of 5% aqueous hydrochloric acid, 100 mL of saturated aqueous sodium bicarbonate and 100 mL of saturated brine, dried over magnesium sulfate, filtered, and concentrated under reduced pressure. The obtained solid was washed several times with hexane, filtered, and dried at 80° C. under reduced pressure. As a result, 22.0 g of a tosylated product was obtained.

The measurement results of ¹ H-NMR (AL300, 300 MHz manufactured by JEOL Ltd.) of the obtained product are as follows:

¹ H-NMR (CDCl ₃ ) results:

δ (ppm) = 7.8 (d, 2H, J = 7.8Hz, tosyl), 7.3 (d, 2H, J = 7.8, tosyl), 4.2 (t, 2H, J = 4.2Hz, sulfonate ortho position of PEGM), 3.6-3.5 (m, methylene of PEGM), 3.4 (s, 3H, methoxy at the end of the PEGM chain), 2.4 (s, 3H, methyl of tosyl)

[Synthesis Example 2: Synthesis of Polyethyleneimine-b-Polyethylene Glycol Copolymer]

Under a nitrogen atmosphere, 19.3 g (9.0 mmol) of tosylated polyethylene glycol obtained in Synthesis Example 1 and 30.0 g (3.0 mmol) of branched polyethyleneimine (manufactured by Nippon Catalyst Co., Ltd.) were mixed at 60° C. EPOMIN SP200) was dissolved and mixed by stirring. To the resulting solution was added 0.18 g of potassium carbonate, and the mixture was stirred for 6 hours at a reaction temperature of 120°C. After completion of the reaction, the product was diluted with THF solvent, the residue was removed, and then concentrated under reduced pressure at 30°C. The obtained solid product was redissolved in THF solvent, and heptane was added to the obtained solution, and the residue was again allowed to settle. The residue was isolated by filtration and concentrated under reduced pressure. As a result, 48.1 g of a pale yellow solid product was obtained (yield: 99%).

The results of ¹ H-NMR and ¹³ C-NMR (AL300 manufactured by JEOL Ltd., 300 Hz) and the results of elemental analysis of the obtained product are as follows.

¹ H-NMR (CDC1 ₃ ) results:

δ (ppm) = 3.57 (brs, methylene of PEGM), 3.25 (s, 3H, methoxy at the end of the PEGM chain), 2.65-2.40 (m, ethylene of branched PEI).

¹³ C-NMR (DMSO-d ₆ ) results:

δ(ppm)=39.9(s), 41.8(s), 47.6(m), 49.5(m), 52.6(m), 54.7(m), 57.8(m) (the above are ethylene groups of branched PEI) , 59.0(s), 70.5(m), 71.8(s) (the above are the methylene and terminal methoxy groups of PEGM).

Results of elemental analysis: C (53.1%), H (10.4%), N (19.1%)

[Synthesis Example 3: Synthesis of polyethyleneimine-b-polyethylene glycol-b-bisphenol A epoxy resin]

In 100 mL of NN-dimethylacetamide, dissolve 37.4 g (20 mmol) of EPICLONAM-040-P (manufactured by DIC Corporation, bisphenol A-type epoxy resin, epoxy equivalent: 933) and 2.72 g (16 mmol) 4-phenylphenol, and to the resulting solution was added 0.52 mL of 65% ethyltriphenylphosphine acetate in ethanol. Under nitrogen atmosphere, the reaction was carried out at 120°C for 6 hours. The resulting product was allowed to cool and added dropwise to a large volume of water. The resulting precipitate was washed with copious amounts of water. The residue was dried under reduced pressure, as a result of which a modified bisphenol A-type epoxy resin was obtained. The product yield was 98%. The integral ratio of epoxy groups was investigated by ¹ H-NMR measurement. It was found that 0.95 epoxy rings remained in each bisphenol A-type epoxy resin molecule, and the product was a monofunctional epoxy resin having a bisphenol A skeleton.

The ¹ H-NMR (AL300 manufactured by JEOL Ltd., 300 MHz) measurement results of the obtained monofunctional epoxy resin are as follows:

¹ H-NMR (CDCl ₃ ) results:

δ(ppm): 7.55～6.75(m), 4.40～3.90(m), 3.33(m), 2.89(m), 2.73(m), 1.62(s)

In the methanol (150mL) solution of 20g (0.8mmol) polyethylenimine-b-polyethylene glycol copolymer obtained in synthesis example 2, add dropwise 3.2g (1.6mmol) modified epoxy resin under nitrogen atmosphere acetone (50 mL), and the mixture was stirred at 50° C. for 2 hours. After the reaction was completed, the solvent was distilled off under reduced pressure, and the product was further dried under reduced pressure. As a result, a polyethyleneimine-b-polyethylene glycol-b-bisphenol A-type epoxy resin was obtained. The yield is 100%.

The ¹ H-NMR (AL300, 300 MHz manufactured by JEOL Ltd.) measurement results of the obtained product are as follows:

¹ H-NMR (CDCl ₃ ) results:

δ(ppm)＝7.55～6.75(m), 4.40～3.90(m), 3.57(brs), 3.33(m), 3.25(s), 2.89(m), 2.73(m), 2.65-2.40(m) , 1.62(s).

[Example 1: Synthesis of Protected Polymer (1-1)]

In 270 mL of N,N-dimethylacetamide, 19.3 g (9.0 mmol) of tosylated polyethylene glycol obtained in Synthesis Example 1 and 30.0 g (3.0 mmol) of branched-chain Polyacetimide (EPOMIN SP200 manufactured by Nippon Catalyst Co., Ltd.) was dissolved, and 0.18 g of potassium carbonate was added thereto. The resulting mixture was stirred at a reaction temperature of 120° C. for 6 hours. After completion of the reaction, solid matter was removed, the product was concentrated at 70°C under reduced pressure, and a mixture of 200 mL of ethyl acetate and 600 mL of hexane was added to the residue to obtain a precipitate. The precipitate was separated and diluted with THF solvent. The residue was removed and the product was concentrated under reduced pressure at 30°C. The obtained solid product was redissolved in THF solvent, and heptane was added thereto, and the residue was again allowed to settle. The residue was isolated by filtration and concentrated under reduced pressure. As a result, 47.8 g of a pale yellow solid product was obtained (yield: 98%).

The results of ¹ H-NMR and ¹³ C-NMR (AL300, 300 Hz manufactured by JEOL Ltd.) of the obtained product are as follows.

¹ H-NMR (CDCl ₃ ) results:

δ (ppm) = 3.57 (brs, the methylene group of PEGM), 3.25 (s, 3H, the methoxyl group at the end of the PEGM chain), 3.16 (m, 2H, the methylene group adjacent to the acetyl nitrogen), 2.65～ 2.40 (m, ethylene group of branched PEI), 1.90 (brs, 3H, acetyl group of primary nitrogen).

¹³ C-NMR (DMSO-d ₆ ) results:

δ(ppm)=22.9(s) (acetyl group of primary nitrogen), 39.9(s), 41.8(s), 47.6(m), 49.5(m), 52.6(m), 54.7(m), 57.8(m ) (the above is the ethylene group of branched PEI), 59.0 (s), 70.5 (m), 71.8 (s) (the above are the methylene and terminal methoxy groups of PEGM), 173.4 (m) (acetyl) .

By calculating the integral ratio of the 1.90 ppm peak due to the acetylated primary amines in the branched polyethyleneimine in the ¹ H-NMR measurement, it can be known that 11 mol% of the primary amines in the branched polyethyleneimine are acetylated.

[Example 2: Synthesis of Protected Polymer (1-2)]

In 270 mL of N,N-dimethylacetamide, 19.3 g (9.0 mmol) of the tosylated polyethylene glycol obtained in Synthesis Example 1 and 30.0 g (3.0 mmol) of branched polyethylene glycol were mixed under a nitrogen atmosphere. Ethyleneimine (EPOMIN SP200 manufactured by Nippon Catalyst Co., Ltd.) was dissolved, and 0.18 g of potassium carbonate was added thereto. The resulting mixture was stirred at a reaction temperature of 140° C. for 6 hours. After completion of the reaction, solid matter was removed, the product was concentrated at 70° C. under reduced pressure, and a mixture of 200 mL of ethyl acetate and 600 mL of hexane was added to the residue to obtain a precipitate. The precipitate was separated and diluted with THF solvent. The residue was removed and the product was concentrated under reduced pressure at 30°C. The obtained solid product was redissolved in THF solvent, and heptane was added thereto, and the residue was again precipitated. The residue was isolated by filtration and concentrated under reduced pressure. As a result, 48.0 g of a pale yellow solid product was obtained (yield: 98%).

The results of ¹ H-NMR and ¹³ C-NMR (AL300, 300 Hz manufactured by JEOL Ltd.) of the obtained product are as follows.

¹ H-NMR (CDCl ₃ ) results:

δ (ppm) = 3.57 (brs, the methylene group of PEGM), 3.25 (s, 3H, the methoxyl group at the end of the PEGM chain), 3.16 (m, 2H, the methylene group adjacent to the acetyl nitrogen), 2.65～ 2.40 (m, ethylene group of branched PEI), 1.90 (brs, 3H, acetyl group of primary nitrogen).

¹³ C-NMR (DMSO-d ₆ ) results:

δ(ppm)=22.9(s) (acetyl group of primary nitrogen), 39.9(s), 41.8(s), 47.6(m), 49.5(m), 52.6(m), 54.7(m), 57.8(m ) (the above is the ethylene group of branched PEI), 59.0 (s), 70.5 (m), 71.8 (s) (the above are the methylene and terminal methoxy groups of PEGM), 173.4 (m) (acetyl) .

By calculating the integral ratio of the 1.90 ppm peak due to the acetylated primary amines in the branched polyethyleneimine in the ¹ H-NMR measurement, it can be seen that 30 mol% of the primary amines in the branched polyethyleneimine are acetylated.

[Example 3: Synthesis of Protected Polymer (1-3)]

In 45 g of chloroform, 9.98 g (N equivalent: 145 mol) of the protected polymer (1-2) obtained in Example 2 (30 mol% of the primary amine being acetylated polyethyleneimine-b-polyethylene glycol copolymer) dissolved. To the obtained solution, 1.48 g of acetic anhydride was gradually added with stirring at 30°C to perform an acetylation reaction for 2 hours. After the reaction, the product was treated with a strong base, and the resulting residue was filtered. The product was concentrated under reduced pressure, as a result of which 10.5 g of a pale yellow solid product was obtained (yield: 99%).

The results of ¹ H-NMR and ¹³ C-NMR (AL300, 300 Hz manufactured by JEOL Ltd.) of the obtained product are as follows.

¹ H-NMR (CDCl ₃ ) results:

δ (ppm) = 3.57 (brs, the methylene group of PEGM), 3.25 (s, 3H, the methoxyl group at the end of the PEGM chain), 3.16 (m, 2H, the methylene group adjacent to the acetyl nitrogen), 2.65～ 2.40 (m, ethylene group of branched PEI), 2.11 (brs, 3H, acetyl group of secondary nitrogen), 1.90 (brs, 3H, acetyl group of primary nitrogen).

¹³ C-NMR (DMSO-d ₆ ) results:

δ(ppm)=21.4(s) (acetyl group of secondary nitrogen), 22.9(s) (acetyl group of primary nitrogen), 39.9(s), 41.8(s), 47.6(m), 49.5(m), 52.6 (m), 54.7(m), 57.8(m) (the above is the ethylene group of branched PEI), 59.0(s), 70.5(m), 71.8(s) (the above are the methylene group and terminal formazan of PEGM oxy), 173.4(m) (acetyl).

Calculate the integral ratio of the 1.90ppm peak and the 2.11ppm peak due to the acetylated primary amine and the acetylated secondary amine in the branched-chain polyethyleneimine in the ¹ H-NMR measurement, and it can be seen that 58mol% of the branched-chain polyethyleneimine of primary amines and 11 mol% of secondary amines were acetylated.

[Example 4: Synthesis of Protected Polymer (1-4)]

In 45 g of chloroform, 9.98 g (N equivalent: 145 mmol) of the protected polymer (1-2) obtained in Example 2 (polyethyleneimine-b-polyethylenediamine in which 30 mol% of the primary amine was acetylated Alcohol copolymer) dissolved. To the obtained solution, 2.96 g of acetic anhydride was gradually added with stirring at 30° C. to perform an acetylation reaction for 2 hours. After the reaction, the product was treated with a strong base, and the resulting residue was filtered. The product was concentrated under reduced pressure, as a result of which 11.0 g of a pale yellow solid product was obtained (yield: 98%).

The results of ¹ H-NMR and ¹³ C-NMR (AL300, 300 Hz manufactured by JEOL Ltd.) of the obtained product are as follows:

¹ H-NMR (CDCl ₃ ) results:

δ (ppm) = 3.57 (brs, methylene of PEGM), 3.25 (s, 3H, methoxy at the end of the PEGM chain), 3.16 (m, 2H, methylene N adjacent to acetyl nitrogen), 2.65 -2.40(m,

ethylene of branched PEI), 2.11 (brs, 3H, acetyl of secondary nitrogen), 1.90 (brs, 3H, acetyl of primary nitrogen).

¹³ C-NMR (DMSO-d ₆ ) results:

δ(ppm)=21.4(s) (acetyl group of secondary nitrogen), 22.9(s) (acetyl group of primary nitrogen), 39.9(s), 41.8(s), 47.6(m), 49.5(m), 52.6 (m), 54.7(m), 57.8(m) (the above is the ethylene group of branched PEI), 59.0(s), 70.5(m), 71.8(s) (the above are the methylene group and terminal formazan of PEGM oxy), 173.4(m) (acetyl).

Calculate the integral ratio of the 1.90ppm peak and the 2.11ppm peak due to the acetylated primary amine and the acetylated secondary amine in the branched-chain polyethyleneimine in the ¹ H-NMR measurement, and it can be seen that 88mol% of the branched-chain polyethyleneimine of primary amines and 22 mol% of secondary amines were acetylated.

[Example 5: Synthesis of Protected Polymer (1-5)]

In 45 g of chloroform, 9.98 g (N equivalent: 145 mmol) of the protected polymer (1-2) obtained in Example 2 (30 mol% of the primary amine being acetylated polyethyleneimine-b-polyethylene glycol copolymer) dissolved. To the obtained solution, 4.44 g of acetic anhydride was gradually added with stirring at 30° C. to perform an acetylation reaction for 2 hours. After the reaction, the product was treated with a strong base, and the resulting residue was filtered. The product was concentrated under reduced pressure, as a result of which 13.7 g of a pale yellow solid product was obtained (yield: 95%).

The results of ¹ H-NMR and ¹³ C-NMR (AL300 manufactured by JEOL Ltd., 300 Hz) of the obtained product are as follows:

¹ H-NMR (CDCl ₃ ) results:

δ (ppm) = 3.57 (brs, the methylene group of PEGM), 3.25 (s, 3H, the methoxy group at the end of the PEGM chain), 3.16 (m, 2H, the methylene group adjacent to the acetyl nitrogen), 2.65- 2.40 (m, ethylene group of branched PEI), 2.11 (brs, 3H, acetyl group of secondary nitrogen), 1.90 (brs, 3H, acetyl group of primary nitrogen).

¹³ C-NMR (DMSO-d ₆ ) results:

δ(ppm)=21.4(s) (acetyl group of secondary nitrogen), 22.9(s) (acetyl group of primary nitrogen), 39.9(s), 41.8(s), 47.6(m), 49.5(m), 52.6 (m), 54.7(m), 57.8(m) (the above is the ethylene group of branched PEI), 59.0(s), 70.5(m), 71.8(s) (the above are the methylene group and terminal formazan of PEGM oxy), 173.4(m) (acetyl).

Calculate the integral ratio of the 1.90ppm peak and the 2.11ppm peak due to the acetylated primary amine and the acetylated secondary amine in the branched-chain polyethyleneimine in the ¹ H-NMR measurement, and it can be seen that 96mol% of the branched-chain polyethyleneimine of primary amines and 54 mol% of secondary amines were acetylated.

[Comparative Example 1: Synthesis of Protected Polymer (1')]

In 45 g of chloroform, 9.98 g (N equivalent: 145 mmol) of the protected polymer (1-2) obtained in Example 2 (polyethyleneimine-b-polyethylenediamine in which 30 mol% of the primary amine was acetylated Alcohol copolymer) dissolved. To the obtained solution, 7.40 g of acetic anhydride was gradually added with stirring at 30°C to perform an acetylation reaction for 2 hours. After the reaction, the product was treated with a strong base, and the resulting residue was filtered. The product was concentrated under reduced pressure, as a result of which 12.0 g of a pale yellow solid product was obtained (yield: 92%).

The results of ¹ H-NMR and ¹³ C-NMR (AL300 manufactured by JEOL Ltd., 300 Hz) of the obtained product are as follows:

¹ H-NMR (CDCl ₃ ) results:

δ (ppm) = 3.57 (brs, the methylene group of PEGM), 3.25 (s, 3H, the methoxy group at the end of the PEGM chain), 3.16 (m, 2H, the methylene group adjacent to the acetyl nitrogen), 2.65- 2.40 (m, branched PEI ethylene), 2.11 (brs, 3H, acetyl of secondary nitrogen), 1.90 (brs, 3H, acetyl of primary nitrogen).

¹³ C-NMR (DMSO-d ₆ ) results:

δ(ppm)=21.4(s) (acetyl group of secondary nitrogen), 22.9(s) (acetyl group of primary nitrogen), 39.9(s), 41.8(s), 47.6(m), 49.5(m), 52.6 (m), 54.7(m), 57.8(m) (the above is the ethylene group of branched PEI), 59.0(s), 70.5(m), 71.8(s) (the above are the methylene group and terminal formazan of PEGM oxy), 173.4(m) (acetyl).

Calculate the integral ratio of the 1.90ppm peak and the 2.11ppm peak due to the acetylated primary amine and the acetylated secondary amine in the branched-chain polyethyleneimine in the ¹ H-NMR measurement, and it can be seen that 96mol% of the branched-chain polyethyleneimine of primary amines and 98 mol% of secondary amines were acetylated.

[Example 6: Synthesis of Protected Polymer (2-1)]

The acetone (50mL) solution of 3.2g (1.6mmol) modified epoxy resin (that is, the monofunctional epoxy resin with bisphenol A skeleton synthesized in Synthesis Example 3) was added dropwise to 20g (1.25mmol) in a nitrogen atmosphere. ) A methanol (150 mL) solution of an acetylated product of polyethyleneimine-b-polyethylene glycol copolymer (ie, the protected polymer (1-3) obtained in Example 3). The resulting mixture was stirred at 50°C for 2 hours. After the reaction, the solvent was distilled off under reduced pressure, and the product was dried under reduced pressure to obtain polyacetylethyleneimine-b-polyethylene glycol-b-bisphenol A type epoxy resin. The yield is 100%.

The results of ¹ H-NMR (AL300, 300 Hz manufactured by JEOL Ltd.) of the obtained product are as follows:

¹ H-NMR (CDCl ₃ ) results:

δ (ppm) = 7.55 ~ 6.75 (m), 4.40 ~ 3.90 (m), 3.57 (brs, methylene of PEGM), 3.33 (m), 3.25 (s, 3H, methoxy at the end of the PEGM chain), 3.16(m, 2H, methylene group adjacent to acetyl nitrogen), 2.89(m), 2.73(m), 2.65~2.40(m, ethylene group of branched PEI), 2.11(brs, 3H, secondary acetyl on nitrogen), 1.90 (brs, 3H, acetyl on primary nitrogen), 1.62 (s).

Calculate the integral ratio of the 1.90ppm peak and the 2.11ppm peak due to the acetylated primary amine and the acetylated secondary amine in the branched-chain polyethyleneimine in the ¹ H-NMR measurement, and it can be seen that 56mol% of the branched-chain polyethyleneimine of primary amines and 12 mol% of secondary amines were acetylated.

[Example 7: Synthesis of Silver Colloid Solution Using the Protected Polymer (1-1) of Example 1]

To a 1 L reactor, 180 g of pure water, 13.5 g of an aqueous solution of the protected polymer (1-1) obtained in Example 1, and 113 g (1.27 mol) of N,N-dimethylaminoethanol were sequentially added, and stirred to Prepare a mixed solution of protective polymer and reducing agent. In a separate container, 72.0 g (0.424 mol) of silver nitrate was dissolved in 120 g of pure water. The obtained silver nitrate aqueous solution was added dropwise to the reactor at 40° C. over about 30 minutes, and the mixture was stirred at 50° C. for 5 hours. After the reaction was completed and cooled, 1.9 L (about 4 times the volume of the reaction mixture) of acetone, a poor solvent, was added thereto, and the resulting mixture was stirred for 5 minutes, and then kept standing for about 1 hour. As a result, a complex composed of silver nanoparticles and a protective polymer was isolated by settling. After removing the supernatant, the resulting precipitate was separated by centrifugation. After the separated paste-like precipitate was washed with pure water, it was centrifuged again. The obtained paste-like precipitate was dispersed in 80 g of pure water, and residual acetone was distilled off. The product was concentrated under reduced pressure to a non-volatile content of about 60%. As a result, 77.0 g of an aqueous silver colloid solution was obtained (46.5 g as non-volatile matter, yield: 97%). The results of thermal analysis (Tg/DTA) showed that the silver content in the non-volatile matter was 95.8%.

[Example 8: Synthesis of Silver Colloid Solution Using the Protected Polymer (1-2) of Example 2]

In this example, except that 14.2 g of the aqueous solution of the protected polymer (1-2) obtained in Example 2 was used instead of 13.5 g of the aqueous solution of the protected polymer (1-1) obtained in Example 1, the In the same manner as in Example 7, 73.0 g of an aqueous silver colloid solution having a non-volatile matter content of about 60% was obtained (45.1 g as a non-volatile matter, yield: 94%). The results of thermal analysis (Tg/DTA) showed that the silver content in non-volatile matter was 96.0%.

[Example 9: Synthesis of Silver Colloid Solution Using the Protected Polymer (1-3) of Example 3]

In this example, except that 15.5 g of the aqueous solution of the protected polymer (1-3) obtained in Example 3 was used instead of 13.5 g of the aqueous solution of the protected polymer (1-1) obtained in Example 1, the same as in the embodiment In the same manner as in Example 7, 74.0 g of an aqueous silver colloid solution having a non-volatile matter content of about 60% was obtained (46.2 g as a non-volatile matter, yield: 96%). The results of thermal analysis (Tg/DTA) showed that the silver content in non-volatile matter was 96.0%.

[Example 10: Synthesis of Silver Colloid Solution Using the Protected Polymer (1-4) of Example 4]

In this example, except that 17 g of the aqueous solution of the protected polymer (1-4) obtained in Example 4 was used instead of 13.5 g of the aqueous solution of the protected polymer (1-1) obtained in Example 1, the same as in Example 1 In the same manner as in 7, 75.0 g of an aqueous silver colloid solution having a non-volatile matter content of about 60% was obtained (45.6 g as a non-volatile matter, yield: 96%). The results of thermal analysis (Tg/DTA) showed that the silver content in the non-volatile matter was 96.1%.

[Example 11: Synthesis of Silver Colloid Solution Using the Protected Polymer (1-5) of Example 5]

In this example, except that 17.5 g of the aqueous solution of the protected polymer (1-5) obtained in Example 5 was used instead of 13.5 g of the aqueous solution of the protected polymer (1-1) obtained in Example 1, the same as in the embodiment In the same manner as in Example 7, 70.0 g of an aqueous silver colloid solution having a non-volatile matter content of about 60% was obtained (45.0 g as a non-volatile matter, yield: 94%). The results of thermal analysis (Tg/DTA) showed that the silver content in the non-volatile matter was 96.4%.

[Comparative Example 2: Synthesis of Silver Colloid Solution Using Protected Polymer (1′) of Comparative Example 1]

In this example, except that 19.9 g of the aqueous solution of the protected polymer (1') obtained in Comparative Example 1 was used instead of 13.5 g of the aqueous solution of the protected polymer (1-1) obtained in Example 1, the same as in Example 1 In the same manner as in 7, 70.0 g of an aqueous silver colloid solution having a non-volatile matter content of about 60% was obtained (43.6 g as a non-volatile matter, yield: 91%). The result of thermal analysis (Tg/DTA) showed that the silver content in the non-volatile matter was 95.5%.

[Example 12: Synthesis of silver colloidal solution using the protective polymer (2-1) of Example 6]

In this example, except that 16.9 g of the aqueous solution of the protected polymer (2-1) obtained in Example 6 was used instead of 13.5 g of the aqueous solution of the protected polymer (1-1) obtained in Example 1, the In the same manner as in Example 7, 76.0 g of an aqueous silver colloid solution having a non-volatile matter content of about 60% was obtained (45.8 g as a non-volatile matter, yield: 95%). The results of thermal analysis (Tg/DTA) showed that the silver content in the non-volatile matter was 95.6%.

[Comparative Example 3: Synthesis of Silver Colloidal Solution Using the Compound of Synthesis Example 2]

In this example, except that an aqueous solution prepared by dissolving 3.5 g of the compound obtained in Synthesis Example 2 in 9.5 g of pure water was used instead of 13.5 g of the aqueous solution of the protected polymer (1-1) obtained in Example 1 , and in the same manner as in Example 7, 74.0 g of a silver colloid aqueous solution having a non-volatile matter content of about 60% was obtained (45.7 g as a non-volatile matter, yield: 95%). The results of thermal analysis (Tg/DTA) showed that the silver content in non-volatile matter was 96.0%.

[Comparative Example 4: Synthesis of Silver Colloid Solution Using the Compound of Synthesis Example 3]

In this example, except that an aqueous solution prepared by dissolving 4.1 g of the compound obtained in Synthesis Example 3 in 9.5 g of pure water was used instead of 13.5 g of the aqueous solution of the protected polymer (1-1) obtained in Example 1 , and in the same manner as in Example 7, 77.0 g (45.5 g as a non-volatile matter, yield: 95%) of a silver colloid aqueous solution having a non-volatile matter content of about 60% was obtained. The results of thermal analysis (Tg/DTA) showed that the silver content in the non-volatile matter was 95.5%.

For the metal thin films prepared by using the silver colloid solutions obtained in Examples 7 to 12 and Comparative Examples 2 to 4, the resistivity and the average particle diameter were measured as described above. The amount of acetone used for the sedimentation treatment and the time taken for the treatment during the synthesis are shown in Table 2. The obtained silver colloid solution was left to stand at room temperature (25 to 35° C.) for 1 week, and the stability of the solution was evaluated from the appearance. The results are shown in Tables 1 and 2. In Table 1, O.L. means overload.

The results show that when the protective polymer used has a primary amine acetylation ratio of 5 to 100 mol% and a secondary amine acetylation ratio of 0 to 50 mol% in the polyalkyleneimine segment, good electrical conductivity is exhibited , dispersion stability and ease of purification and separation.

Table 1

Table 2

Claims (13)

1. a metal nanoparticle protection polymkeric substance, comprises in molecule:

Poly-ethanoyl alkylene imine segment (A), wherein, in poly (alkylenimines), the primary amine of 5 ~ 100mol% is acetylation and in poly (alkylenimines), the secondary amine of 0 ~ 50mol% is acetylation; And

Hydrophilic segment (B).

2. metal nanoparticle protection polymkeric substance according to claim 1, comprises hydrophobic chain segment (C) further in molecule.

3. metal nanoparticle protection polymkeric substance according to claim 1 and 2, wherein, described hydrophilic segment (B) comprises polyoxyalkylene chain.

4. the metal nanoparticle protection polymkeric substance according to Claims 2 or 3, wherein, described hydrophobic chain segment (C) comprises the structure deriving from epoxy resin.

5. according to any one of Claims 1 to 4 metal nanoparticle protection polymkeric substance, wherein, the unit number of the alkylene imine in described poly-ethanoyl alkylene imine segment (A) 5 ~ 2, in the scope of 500.

6. the metal nanoparticle protection polymkeric substance according to any one of Claims 1 to 5, wherein, described metal nanoparticle protection polymkeric substance has 1,000 ~ 100, the weight-average molecular weight of 000 scope.

7. a manufacture method for metal nanoparticle protection polymkeric substance, comprising:

Make to have the compound of poly (alkylenimines) segment and there is the compound polymerization of hydrophilic segment (B), making the acetylize of alkylene imine unit with acetylizing agent simultaneously.

8. a manufacture method for metal nanoparticle protection polymkeric substance, comprising:

The compound in molecule with poly (alkylenimines) segment and hydrophilic segment (B) is reacted as presoma and acetylizing agent, thus makes the acetylize of alkylene imine unit.

9. a colloidal metal solution, comprising:

Medium; And

Be scattered in the complex body in described medium; each complex body protects polymkeric substance to form by the metal nanoparticle of metal nanoparticle and the described metal nanoparticle of protection; described metal nanoparticle protection polymkeric substance comprises poly-ethanoyl alkylene imine segment (A) and hydrophilic segment (B); in described poly-ethanoyl alkylene imine segment (A), in poly (alkylenimines), the primary amine of 5 ~ 100mol% is acetylation and in poly (alkylenimines), the secondary amine of 0 ~ 50mol% is acetylation.

10. colloidal metal solution according to claim 9, wherein, described metal nanoparticle is Nano silver grain.

11. colloidal metal solutions according to claim 9 or 10, wherein, described metal nanoparticle has the particle diameter of 5 ~ 50nm scope.

The manufacture method of 12. 1 kinds of colloidal metal solutions, comprising:

When there is metal nanoparticle protection polymkeric substance; in media as well reducing metal ions is become metal nanoparticle; described metal nanoparticle protection polymkeric substance comprises poly-ethanoyl alkylene imine segment (A) and hydrophilic segment (B) in molecule; in described poly-ethanoyl alkylene imine segment (A), in poly (alkylenimines), the primary amine of 5 ~ 100mol% is acetylation and in poly (alkylenimines), the secondary amine of 0 ~ 50mol% is acetylation.

The manufacture method of 13. colloidal metal solutions according to claim 12, wherein, described metal nanoparticle is Nano silver grain.