KR20160070797A - Metal nanoparticle-protecting polymer and metal colloidal solution, and method for producing same - Google Patents

Abstract

The metal nanoparticle-protecting polymer is obtained by polymerizing 5 to 95 mol% of the primary amine in the polyalkyleneimine or from 5 to 95 mol% of the primary amine in the polyalkyleneimine and from 5 to 50 mol% (A) a polyacetylalkyleneimine N-oxide segment (A) which is acetylated and oxidized with 0.5 to 95 mol% of the total number of nitrogen atoms in the polyalkyleneimine; And a hydrophilic segment (B) in the molecule. A method for producing a metal nanoparticle-protective polymer; A metal colloid solution comprising a medium and a complex dispersed in the medium, wherein each composite contains metal nanoparticles - metal nanoparticles protected with a protective polymer; And a method for producing a metal colloid solution are also provided.

Description

Technical Field [0001] The present invention relates to a metal nanoparticle-protective polymer and a metal colloid solution,

The present invention relates to a polymer colloid solution for use as a protective agent for metal nanoparticles, a polymer containing a polyacetylalkyleneimine N-oxide segment and a hydrophilic segment, or a polymer containing a hydrophobic segment in addition to the two segments mentioned above, And a method for producing a metal colloid solution. The present invention also relates to a process for the preparation of the polymers and polymers mentioned above.

The metal nanoparticles are nanoparticles having a particle diameter of 1 to several hundred nanometers and a significantly large specific surface area. Metal nanoparticles having such characteristics are attracting much attention in various fields and are expected to be used in electronic materials, catalysts, magnetic materials, optical materials, various sensors, coloring materials, and medical examinations.

Printed circuit boards and semiconductor devices are fabricated through photolithography processes that primarily involve a series of complex manufacturing steps. In this situation, printable electronic device manufacturing technology is attracting attention. A printable electronic device manufacturing technique involves forming a pattern by dispersing recently developed metal nanoparticles in a medium to produce an ink composition, printing using an ink composition, and assembling the pattern into a device.

This technique is called printing electronics. Print electronics provides the potential and economic efficiency for mass production of electronic circuit patterns and roll-to-roll semiconductor devices, because the technology can be used for on-demand manufacturing, , And resource conservation. The technology is also expected to provide a way for low cost manufacturing processes such as display devices, light emitting devices, and IC tags (RFID). The conductive material ink used in printing electronics may contain metal nanoparticles such as gold, silver, platinum, copper, and the like. Due to economical reasons and ease of handling, the development of inks containing silver nanoparticles and silver nanoparticles has been achieved first.

Silver in particle form at the nanometer level exhibits significantly higher specific surface area and increased surface energy than bulk silver. Silver nanoparticles tend to fuse together to reduce surface energy. As a result, the particles fuse together at temperatures much lower than the melting point of the bulk silver. This phenomenon is called the quantum size effect (Kubo effect) and on the one hand shows the advantage of using silver nanoparticles as a conductive material. On the other hand, the strong tendency of the metal nanoparticles to fuse with each other compromises the stability of the metal nanoparticles and degrades the storage stability. To stabilize the metal nanoparticles, the metal nanoparticles need to be protected with a protecting agent that prevents fusion.

Typically, nanomaterials (compounds with nanometer-scale dimensions in general) tend to be manufactured and costly through special processes due to their size. This has inhibited the widespread use of nanomaterials. In order to produce metal nanoparticles at low cost, a liquid phase reduction process that does not require special equipment such as a vacuum process chamber is advantageous. The liquid phase reduction process is a process for obtaining metal nanoparticles by causing a metal compound to react with a reducing agent in a solvent. According to the known technique, the reduction is carried out in the presence of a compound called a dispersion stabilizer or a protective agent to control the shape and particle size of the metal nanoparticles to be produced and achieve a stable dispersion state. The protective agent is usually a polymer compound designed to have a functional group capable of coordinating with metal particles (for example, a tertiary amino group, a quaternary ammonium group, a heterocyclic group having a basic nitrogen atom, a hydroxyl group, or a carboxyl group) (See, for example, Patent Document 1).

As discussed above, suitable protective agents are used to control the shape and particle size of the metal nanoparticles and stabilize the dispersion, in order to prepare metal nanoparticles that are expected to undergo the desired low temperature fusion. However, the protective agent functions as a resistance component to the bulk metal and deteriorates conduction performance. Depending on the amount of the protective agent used, the desired low-temperature sintering property (the characteristic that the resistivity of the thin film obtained by baking the thin film of the metal-nanoparticle-containing conductive ink at a temperature in the range of 100 ° C to 150 ° C is on the order of 10 ^-6 ohm · cm) May not appear. From the viewpoint of the design of the conductive material, the protective agent is required to have the ability to produce small particles, the ability to stably disperse these particles, and the capability of not interfering with the fusion between metal nanoparticles by rapid desorption from the particle surface during sintering . In view of the preparation of metal nanoparticles, the protective agent needs to exhibit the ability to facilitate purification and separation of the prepared metal nanoparticles. The protective agent preferably exhibits both of these capabilities. Examples of the protectants disclosed so far include commercially available polymeric pigment dispersants such as Solsperse (trademark, manufactured by Zeneca) and FLOWLEN (trademark, Kyoei Chemical Co., Ltd. (Produced by Kyoeisha Chemical Co., Ltd.), a pigment-compatible group (amine) in the main chain / side chain and a polymer having two or more protective segments, and a copolymer having a polyethyleneimine segment and a polyethylene oxide segment . However, these dispersants hardly achieve all the required capabilities described above, and further improvement is required (see, for example, Patent Documents 2 to 4).

Japanese Patent Application Publication No. 2004-346429 Japanese Patent Application Publication No. 1999-080647 Japanese Patent Application Publication No. 2006-328472 Japanese Patent Application Publication No. 2008-037884

It is an object of the present invention to provide a metal material which exhibits more practical electrical conductivity by intentionally controlling and imparting various properties such as ability to control metal nanoparticles, high dispersion stability, excellent low-temperature sintering property, and ease of purification and separation of metal nanoparticles. Nanoparticle-protecting polymer. Metal colloid solutions, and methods of making metal nanoparticle-protective polymers and metal colloidal solutions are also provided.

The inventors of the present invention have found that when a polyalkyleneimine segment containing a polyethyleneimine is combined with a hydrophilic segment containing a polyoxyalkylene chain, a hydrophobic segment such as an epoxy resin and an epoxy resin, It has already been disclosed that the system polymer is useful for the production of metal nanoparticles (see Patent Document 4). However, according to the technique disclosed in Patent Document 4, the above-described characteristics are not sufficiently achieved. On the basis of further studies, the inventors have found that a novel, novel process for the preparation of a novel polyalkyleneimine segment by acylation of a primary amine moiety or primary and secondary amine moiety in a polyalkyleneimine segment and subsequent conversion of the tertiary amine moiety to N- It has been found effective to use an acetylated N-oxide-based polymer and the present invention has been devised.

In other words, the present invention relates to a polyacetylalkyleneimine N-oxide segment (also referred to as " polyacetylenealkylenimine N-oxide segment ") obtained by acetylating a primary amine moiety or primary and secondary amine moiety in a polyalkyleneimine, A); And a hydrophilic segment (B) in the molecule. The present invention also relates to a method for producing a metal nanoparticle-protective polymer, a metal colloid solution comprising a metal nanoparticle-containing complex dispersed in a medium, said composite being prepared by using a metal nanoparticle-protective polymer as a protective agent, And a process for producing a metal colloid solution.

The metal colloid solution obtained in the present invention exhibits excellent low-temperature sintering properties. Conduction performance at low temperatures is very good because the protective polymer used in the present invention is readily desorbed from the surface of the metal nanoparticles at low temperatures. Moreover, the size of the metal nanoparticles obtained in the presence of this particular protective polymer is sufficiently small, monodisperse, and has a narrow particle size distribution. Therefore, storage stability is also high. This is because not only the acetylated structural units and the N-oxide structural units in the protective polymer protect the metal nanoparticles, but also the hydrophilic or hydrophobic segments in the polymer cause the particles to be dispersed in the medium. Thus, the dispersion stability of the dispersion is not impaired and the dispersion remains stable for a long time in the solvent.

In the present invention, in the preparation of the metal colloid solution, the metal nanoparticles are obtained by reduction, and in the purification and separation step for removing the following impurities, the protective polymer constituted by the metal nanoparticles and the protective polymer is dissolved in a poor solvent is easily precipitated and separated by a simple operation of adding a poor solvent to the dispersion of the composite. This is achieved by the strong cohesive force of the protective polymer. This method is industrially advantageous because it requires little complex steps and fine condition setting.

Furthermore, the metal nanoparticles in the metal colloid solution obtained in the present invention have large specific surface area, high surface energy, and plasmon absorption characteristic of metal nanoparticles. In addition to these features, polymer dispersions are self-assembled types, which can effectively exhibit dispersion stability and storage stability. Thus, the metal colloid solution has a variety of chemical, electrical, and magnetic properties required in conductive pastes and the like and can be used in a wide variety of fields such as catalysts, electronic materials, magnetic materials, optical materials, various sensors, coloring materials, Can be used.

The metal nanoparticle-protecting polymer of the present invention is a polymer compound having a polyacetylalkyleneimine N-oxide segment (A) and a hydrophilic segment (B), or a polymer compound having a polyacetylalkyleneimine N-oxide segment (A) Segment (B), and hydrophobic segment (C). The dispersion of the metal nanoparticles protected with a protective polymer having such a structure (metal colloid solution) has high dispersion stability and excellent conduction characteristics and has various functions of the metal-containing functional dispersion derived from the metal nanoparticles, It shows enemy and electric functions.

The polyacetylalkyleneimine N-oxide segment (A) in the protective polymer of the present invention contains an acetylalkyleneimine unit and an N-oxide unit capable of forming a coordination bond with a metal or a metal ion, The alkyleneimine N-oxide 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 prepared and stored in a hydrophilic solvent, the resulting metal colloid solution is a polyacetylalkyleneimine N-oxide It can exhibit very good dispersion stability and storage stability because it contains segment (A) and hydrophilic segment (B).

From the viewpoint of industrial production, a simple purification and separation method of a complex prepared by protecting metal nanoparticles prepared by dissolving or dispersing a metal compound in a medium and reducing the metal compound in a medium is an important process . Preferably, such purification and separation methods involve achieving settling by adding a poor solvent, such as acetone, to the solution after the reaction. The acetyl alkyleneimine units and N-oxide units in the protective polymers of the present invention have a high polarity and thus promote rapid association of the metal-nanoparticle-containing complexes. Therefore, sedimentation occurs easily as large aggregates of aggregated particles are formed.

The conductive material obtained by using the metal colloid solution to form a metal colloid solution or a conductive ink, which is a dispersion of the metal nanoparticle-containing complex, is printed or applied to the substrate. In the subsequent sintering step, the acetylalkyleneimine units and the N-oxide units in the protective polymer are easily removed from the surface of the metal nanoparticles even at low temperatures, because the coordination between the units and the metal is weak. As a result, an excellent low-temperature sintering property is exhibited.

In the metal colloid solution of the present invention, the particle size of the dispersion (composite) is determined not only by the molecular weight of the protective polymer used and the degree of polymerization of the polyacetylalkyleneimine N-oxide segment (A) , That is, the structure and composition ratio of the polyacetyl alkyleneimine N-oxide segment (A), the hydrophilic segment (B) described below, and the hydrophobic segment (C) described below.

The polymerization degree of the polyacetyl alkyleneimine N-oxide segment (A) is not particularly limited. If the polymerization degree is too low, the protective polymer may not sufficiently exhibit the ability to protect the metal nanoparticles. If the polymerization degree is too high, the size of the composite particles constituted by the metal nanoparticles and the protective polymer may become excessively large, and the storage stability may be deteriorated. Therefore, the number of alkyleneimine units (degree of polymerization) in the polyacetylalkyleneimine N-oxide segment (A) is usually in the range of 1 to 10,000 in order to improve the metal nanoparticle immobilization ability and prevent the generation of a large dispersed particle , Preferably in the range of 5 to 2,500, and most preferably in the range of 5 to 300.

By acetylating an alkyleneimine moiety in a polyalkyleneimine segment that is a precursor of a polyacetylalkyleneimine N-oxide segment (A) with an acetylating agent, and then contacting the acetylated portion with an oxidizing agent to oxidize the acetylated portion, The acetyl alkyleneimine N-oxide segment (A) can be easily obtained. The segment comprised of the polyalkyleneimine may be any commercially available or synthesizable segment. In view of industrial availability, the segment preferably consists of a branched polyethylene imine or a branched polypropyleneimine, more preferably a branched polyethylene imine.

In the case of preparing a metal colloid solution using a hydrophilic solvent such as water, the hydrophilic segment (B) in the protective polymer of the present invention shows high compatibility with the solvent and maintains the storage stability of the colloidal solution. In the case of using a hydrophobic solvent, the hydrophilic segment (B) having a strong intramolecular or intermolecular cohesive force helps form the core of the dispersed particles. The polymerization degree of the hydrophilic segment (B) is not particularly limited. In the case of using a hydrophilic solvent, if the degree of polymerization is too low, the storage stability is lowered, and if the degree of polymerization is too high, flocculation may occur. In the case of using a hydrophobic solvent, if the degree of polymerization of the hydrophilic segment (B) is too low, the cohesive force between the dispersed particles becomes insufficient, and if the degree of polymerization is too high, compatibility with the solvent is not maintained. From these viewpoints, the degree of polymerization of the hydrophilic segment (B) is usually from 1 to 10,000, preferably from 3 to 3,000, and more preferably from 5 to 1,000 because of ease of production. When the hydrophilic segment is a polyoxyalkylene chain, the polymerization degree is particularly preferably from 5 to 500.

The hydrophilic segment (B) may be any segment made up of commercially available or synthesizable hydrophilic polymer chains. In the case where a hydrophilic solvent is used, the hydrophilic segment (B) is preferably composed of a non-ionic polymer since in this case a very stable colloidal solution is obtained.

Examples of the hydrophilic segment (B) include polyoxyalkylene chains such as polyoxyethylene chain and polyoxypropylene chain, polymer chains of polyvinyl alcohol such as polyvinyl alcohol and partially saponified polyvinyl alcohol, water soluble poly (meth) acrylic acid Ester-based polymer chains such as polyhydroxyethyl acrylate, polyhydroxyethyl methacrylate, dimethylaminoethyl acrylate, and dimethylaminoethyl methacrylate, hydrophilic-substituent-containing polyacylalkyleneimine chains such as poly Polyacrylamide, polyvinylpyrrolidone, and polymer chains composed of polyvinylidene fluoride, polyvinyl pyrrolidone, acetylethyleneimine, polyacetylpropyleneimine, polypropionylethyleneimine, and polypropionylpropyleneimine, and polyacrylamide. do. Of these, polyoxyalkylene chains are preferable because they provide highly stable colloidal solutions and are highly industrially available.

In the present invention, the protective polymer may further contain a hydrophobic segment (C). Particularly, when an organic solvent is used as a medium for a 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 segment of residues of commercially available or synthesizable hydrophobic compounds. Examples of hydrophobic segment (C) are polystyrene, such as polystyrene, polymethylstyrene, polychloromethylstyrene, and polybromomethylstyrene, water-insoluble poly (meth) acrylic acid esters such as polymethyl acrylate , Poly (methyl methacrylate), poly (2-ethylhexyl acrylate), and poly (2-ethylhexyl methacrylate), and hydrophobic-substituent-containing polyacylalkyleneimines such as polybenzoylethyleneimine, (Perfluorooctyl) propionyl} ethylenimine], and poly [N- {3- (3-fluorophenyl) (Perfluorooctyl) propionyl} propyleneimine]; And residues of resins such as epoxy resins, polyurethanes, and polycarbonates. The hydrophobic segment (C) may consist of a residue of a single compound or a residue of a compound obtained by reacting two or more different types of compounds in advance. 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 using it can be easily industrially synthesized This is because the metal colloid solution obtained by using it is well adhered to the substrate during printing or application.

The degree of polymerization of the hydrophobic segment (C) is not particularly limited, but is usually from 1 to 10,000, and preferably from 1 to 10,000 when the hydrophobic segment (C) is a polystyrene, a poly (meth) acrylate, a hydrophobic- Preferably 3 to 3,000, more preferably 10 to 1,000. When the hydrophobic segment (C) is composed of a residue of a resin such as an epoxy resin, a polyurethane, a polycarbonate or the like, the degree of polymerization is usually 1 to 50, preferably 1 to 30, more preferably 1 to 20.

The acetylating agent is reacted with a precursor compound (I) which is a compound having a polyalkyleneimine segment and a hydrophilic segment (B) or a compound having a polyalkyleneimine segment, a hydrophilic segment (B) and a hydrophobic segment (C) By treating the resulting product with an oxidizing agent, the metal nanoparticle-protecting polymer of the present invention can be produced. Alternatively, an acetylating agent can be used during the reaction for preparing the precursor compound (I) from the polyalkyleneimine segment and the hydrophilic segment (B), and then the resulting product can be treated with an oxidizing agent. According to any of these methods, a protective polymer as designed can be readily obtained. The precursor compound (I) can be produced using the process disclosed in Patent Document 4 and Japanese Unexamined Patent Application Publication No. 2006-213887 intact.

After the precursor compound (I) is obtained, the nitrogen atom of the primary amine moiety or the primary and secondary amine moieties in the polyalkyleneimine segment can be acetylated. Alternatively, during the process of preparing the precursor compound (I) using the polyalkyleneimine segment and the hydrophilic segment (B), the nitrogen atom of the primary amine moiety or the primary and secondary amine moieties in the polyalkyleneimine segment Can be acetylated. By the addition of acetyl agent having the structure acetyl (CH ₃ -CO-) performs the acetylation reaction. Subsequently, the nitrogen atom in the acetylated polyalkyleneimine segment is oxidized. Oxidation is carried out by adding a compound having a peroxide structure (-OO- or -NO-) to an aqueous solution of the acetylation precursor compound (I). Examples of compounds having a peroxide structure include hydrogen peroxide, metal peroxides, inorganic peroxides and salts thereof, organic peroxy compounds, and organic peroxides and salts thereof.

Conventional industrial acetylating agents can be used as the acetylating agent. Examples of the acetylating agent include acetic anhydride, acetic acid, dimethylacetamide, ethyl acetate, and chlorinated acetic acid. Among these acetylating agents, acetic anhydride, acetic acid, and dimethylacetamide are particularly preferable in view of availability and ease of handling.

When the polyalkyleneimine segment is derived from a branched polyalkyleneimine compound, primary, secondary, and tertiary amines are uniformly and randomly contained. When such a polyalkyleneimine segment is reacted with any of the acetylating agents described above, one acetyl group is provided for one nitrogen atom of the primary amine and / or secondary amine and the tertiary amine is not acetylated . In other words, the acetylation reaction proceeds on higher primary amines and secondary amines with quantitative reactivity with the acetylating agent used. With respect to the acetylation rates of primary and secondary amines, the acetylation rate for the acetylation reaction is studied. As a result, when 5 to 95 mol% of the primary amine in the polyalkyleneimine segment or 5 to 95 mol% of the primary amine and 5 to 50 mol% of the secondary amine are acetylated, It has been found that a protective polymer is obtained that has dispersion stability and ability to facilitate purification and separation.

The nitrogen atom is then oxidized. When hydrogen peroxide is used as the oxidizing agent, an industrially available 30 to 50 mol% hydrogen peroxide solution is usually used. Examples of metal peroxides include sodium peroxide, potassium peroxide, lithium peroxide, magnesium peroxide, and zinc peroxide. These peroxides are readily available and can be used as oxidizing agents. Examples of inorganic peroxides and salts thereof include persulfates, percarbonates, superacids, perchloric acid, Oxone (a registered trademark of DuPont, an oxidizer mainly composed of potassium hydrogen sulfate), ammonium persulfate, sodium persulfate, potassium persulfate , And sodium percarbonate. Examples of organic peroxy compounds and organic peroxides and salts thereof include peracetic acid, perbenzoic acid, m-chloroperbenzoic acid, benzoyl peroxide, tert-butyl peroxide, 1,2-dimethyl dioxirane, and Davis reagent 2- (phenylsulfonyl) -3-aryloxaziridine). They can also be used as oxidizing agents. Among these oxidizers, 30% hydrogen peroxide solution, ammonium persulfate, oxone, and peracetic acid, which are readily available, easy to handle and less expensive, are preferred.

The oxidizing agent described above can provide one oxygen atom for one nitrogen atom. It is assumed that a one-on-one reaction takes place in the case of tertiary and secondary amines. However, the reaction with primary amines is expected to be somewhat complicated. That is, primary amines do not only react with one oxidant molecule but can also react with the next oxidant molecule. The amount of oxidizing agent added was examined based on these assumptions. As a result, when the oxidizing agent is added in an amount corresponding to 0.5% to 95% of the number of all nitrogen atoms in the polyalkyleneimine segment in the precursor compound (I), excellent conductivity, dispersion stability, and ease of separation ≪ / RTI > is obtained.

In particular, when the polyalkyleneimine segment is based on a branched polyalkyleneimine compound, primary, secondary, and tertiary amines are uniformly and randomly contained. In the case of these amine is reacted with an oxidizing agent, a tertiary amine is an amine-oxide is converted only ^{(CN + (O - C)} -C -) (). The secondary amine reacts further with amine oxides (C-HN ⁺ (O ^- ) ^- C) according to the reaction conditions to form hydroxylamine (CN (OH) -C) and its oxidized form nitrone (C = CN ⁺ (O ^- ) ^- C). Primary amines can be converted to hydroxylamine, (C-NH (OH)), nitroso (C-NO), and nitro (C-NO ₂ ). Because of these possibilities, it is assumed that the resulting protective polymers will contain small amounts of these structures.

The metal nanoparticle-protective polymer of the present invention contains a hydrophilic segment (B) and, optionally, a hydrophobic segment (C) in addition to a polyacetyl alkyleneimine N-oxide segment (A) capable of stabilizing metal nanoparticles . As discussed above, the hydrophilic segment (B) exhibits strong cohesive forces in the hydrophobic solvent and high compatibility with the hydrophilic solvent, and the hydrophobic segment (C) exhibits strong synergism in the hydrophilic solvent and high compatibility with the hydrophobic solvent Indicates the surname. Furthermore, when the hydrophobic segment (C) contains an aromatic ring, the pi electrons of the aromatic ring are believed to interact with the metal and contribute to the stabilization of the metal nanoparticles.

The ratio of the number of moles of the polymer constituting the chain of the polyacetylalkyleneimine N-oxide segment (A) to the number of moles of the polymer constituting the chain of the hydrophilic segment (B), that is, the molar ratio (A) :( B) But is not limited to. The ratio is usually in the range of 1: (1 to 100), preferably 1: (1 to 30) in view of the dispersion stability and storage stability of the obtained metal colloid solution. When the protective polymer also contains the hydrophobic segment (C), the number of moles of the polymer constituting the chain of the hydrophilic segment (B) to the number of moles of the polymer constituting the chain of the polyacetylalkyleneimine N-oxide segment (A) The ratio of the number of moles of the polymer constituting the chain of the hydrophobic segment (C), that is, the molar ratio (A) :( B) :( C) is, from the viewpoint of dispersion stability and storage stability of the obtained metal colloid solution, (1 to 100): (1 to 100), preferably 1: (1 to 30): (1 to 30). The weight-average molecular weight of the metal nanoparticle-protective 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 polymers of the present invention are dispersed in various media and used in the production of metal colloid solutions. The material used as the medium is not particularly limited, and the dispersion may be an oil-in-water (O / W) system or a wastewater (W / O) system. The medium can be selected depending on the process of preparing the metal colloid solution and / or the use of the metal colloid solution. For example, a mixed solvent containing a hydrophilic solvent, a hydrophobic solvent, a hydrophilic solvent and a hydrophobic solvent, or a mixed solvent containing other solvents as described below in addition to the above-mentioned solvents, may be selected and used. When a mixed solvent is used, the amount of the hydrophilic solvent in the O / W system is controlled to be greater than the amount of the hydrophobic solvent, and in the case of the W / O system, the amount of the hydrophobic solvent is controlled to be more than the amount of the hydrophilic solvent. The mixing ratio is not particularly limited, because the ratio depends on the type of solvent used. Generally, in the case of an O / W system, the volume of the hydrophilic solvent is preferably at least 5 times greater than that of the hydrophobic solvent, and in the case of a W / O system the volume of the hydrophobic solvent is preferably less than 5 More than twice as big.

Examples of the hydrophilic solvent include alcohols such as methanol, ethanol, isopropyl alcohol, tetrahydrofuran, acetone, dimethylacetamide, dimethylformamide, ethylene glycol, propylene glycol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol dimethyl ether, Propylene glycol dimethyl ether, dimethyl sulfone oxide, dioxirane, and N-methyl pyrrolidone. These may 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 may be used alone or in combination.

Examples of other solvents that can be used by mixing with a hydrophilic solvent or a hydrophobic solvent include ethyl acetate, propyl acetate, butyl acetate, isobutyl acetate, ethylene glycol monomethyl ether acetate, and propylene glycol monomethyl ether acetate.

The metal nanoparticle-protecting polymer may be dispersed in the medium using any method. Typically, the polymer is allowed to stand at room temperature or stirred to facilitate dispersion of the metal nanoparticle-protective polymer. If necessary, ultrasonic treatment or heat treatment can be performed. When the protective polymer is poorly compatible with the medium due to its crystallinity or the like, the protective polymer may be dispersed or swollen in a small amount of good solvent and then dispersed in the required medium. It is effective to perform ultrasonic treatment or heat treatment during such a process.

A mixture of a hydrophilic solvent and a hydrophobic solvent can be prepared using any mixing method and mixing sequence. Since the compatibility of the protective polymer with various solvents and the dispersibility of the protective polymer depend on the type, composition and other factors of the protective polymer, the solvent mixing ratio, the mixing order of the solvent, the mixing method of the solvent, It can be selected appropriately.

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 may be a salt of metal or an ionic solution. The source of the metal ion may be any water soluble metal compound, for example, an acid anion containing a metal cation and a salt of an acid group anion or a metal. For example, metal ions having metal species such as transition metals are preferably used.

The transition metal ion can be appropriately coordinated to form a complex, regardless of whether it is a transition metal cation (M ^{n +} ) or an anion (ML _x ^n- ) constituted by a halogen bond. In this description, the transition metal refers to the transition metal elements of Groups 4 to 12 and 4 to 6 cycles of the Periodic Table of the Elements.

Examples of the transition metal cation include monovalent, divalent, trivalent or tetravalent cations such as cations (M ^{n +} ) of transition metals, for example, Cr, Co, Ni, Cu, Pd, Ag, Pt and Au. The counter anion of the metal cation may be Cl, NO ₃ , SO ₄ , or an organic anion of a carboxylic acid.

Anions such as metal-containing anions (ML _x ^n- ) in which the metal is coordinated with a halogen, such as AgNO ₃ , AuCl ₄ , PtCl ₄ , or CuF _6, can also be suitably coordinated to form a complex.

Among these metal ions, silver, gold, and platinum ions are preferable because they are spontaneously reduced at room temperature or heated to be converted into nonionic metal nanoparticles. When the obtained metal colloid solution is used as a conductive material, silver ions are preferably used in order to develop electrical conductivity and prevent oxidation of a coating film obtained by printing or coating of a metal colloid solution.

The number of metal species to be contained may be two or more. In such a case, salts or ions of a plurality of metals are added simultaneously or separately, so that metal ions of different chemical species are reduced in the medium to produce metal particles of different species. Thus, a colloidal solution containing a plurality of metal species can be obtained.

In the present invention, metal ions can be reduced using a reducing agent.

The reducing agent may be any of a variety of reducing agents. This can be selected based on the use of the obtained metal colloid solution, the contained metal species, and the like. Examples of reducing agents are hydrogen, boron compounds such as sodium borohydride and ammonium borohydride, alcohols such as methanol, ethanol, propanol, isopropyl alcohol, ethylene glycol and propylene glycol, aldehydes such as formaldehyde, acetaldehyde, and propionaldehyde , An acid such as ascorbic acid, citric acid and sodium citrate, an amine such as propylamine, butylamine, diethylamine, dipropylamine, dimethylethylamine, triethylamine, ethylenediamine, triethylenetetramine, methylaminoethanol, Dimethylaminoethanol and triethanolamine, and hydrazines such as hydrazine and hydrazinecarbonate. Of these, sodium borohydride, ascorbic acid, sodium citrate, methylaminoethanol, and dimethylaminoethanol are preferred because of their high industrial availability and ease of 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 source used is not particularly limited. For example, when it is assumed that the total number of nitrogen atoms constituting the polyacetylalkyleneimine N-oxide segment in the protective polymer is 100 mol, the amount of metal is usually in the range of 1 to 20,000 mol, preferably 1 to 10,000 mol More preferably in the range of 50 to 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 a metal salt or an ionic solution by any method. For example, a metal salt or an ionic solution may 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 may be simultaneously fed into separate containers and mixed have. The mixing method is not particularly limited, and may be stirring.

The reducing agent may be added by any method. For example, the reducing agent may be added as it is, or the reducing agent may be dissolved or dispersed in an aqueous solution or another solvent, and then mixed. 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 the ionic solution. As a further alternative, a solution or dispersion of the protective polymer may be mixed with a metal salt or an ionic solution, and then a reducing agent may be added thereto several days or a few weeks later.

When a metal salt or an ionic solution thereof used in the production method of the present invention is added to a medium in which a protective polymer is dispersed or dissolved, irrespective of whether the system is O / W or W / O, The solution is preferably added as it is or in the form of an aqueous solution. In the case of metal ions such as silver, gold, palladium, platinum, etc., the metal ions are coordinately bonded to an acetylalkyleneimine or N-oxide unit in the polymer, and then spontaneously reduced at room temperature or under heating. Thus, a metal colloid solution is obtained, which is a dispersion of metal nano-particles and a complex of metal nanoparticles protected with a protective polymer, by allowing metal ions to stand or stirring the metal ions at room temperature or in a heated state. However, in order to efficiently reduce the metal ion, a metal colloid solution can be obtained by preferably using a reducing agent as described above and allowing the ion to stand at room temperature or in a heated state or stirring the ions. During this process, the reducing agent is preferably used as it is, or it is prepared in advance as an aqueous solution. The heating temperature depends on, for example, the type of protective polymer and the type of metal, medium, and reducing agent used. Generally speaking, the temperature is 100 DEG C or less, preferably 80 DEG C or less.

As a result of the reduction of the metal ions described above, as the metal nanoparticles precipitate, the surfaces of these particles are protected with a protective polymer that stabilizes the particles. The solution after reduction contains an impurity such as a reducing agent, a counter ion of a metal ion, and a protective polymer that does not contribute to the protection of the metal nanoparticles, and therefore, the performance as a conductive material can not be sufficiently exhibited. Therefore, a purification step to remove impurities is required. Since the protective polymer of the present invention has high protection performance, a poor solvent can be added to the solution after the reaction to efficiently precipitate the complex composed of the metal nanoparticles protected with the protective polymer. The precipitated complex can be concentrated or isolated by centrifugation or the like. After concentration, a suitable medium is added to control the content (concentration) of the non-volatile material according to the use of the metal colloid solution, and the resulting product is used in various applications.

The content of the metal nanoparticles in the metal colloid solution obtained in the present invention is not particularly limited. However, if the content is too low, the characteristics of the metal nanoparticles in the colloidal solution are not sufficiently exhibited. If the content is too high, the relative weight of the metal nanoparticles in the colloid solution increases, and the stability of the colloidal solution is expected to deteriorate due to the imbalance between the excessively large relative weight of the metal nanoparticles and the dispersing ability of the protective polymer. Furthermore, in view of the reducing ability and the coordinating ability of the acetylalkyleneimine N-oxide unit in the protective polymer, the content of the non-volatile substance in the metal colloid solution is preferably in the range of 10 to 80 mass% By mass to 20% by mass to 70% by mass. The metal nanoparticle content in the nonvolatile material is preferably 93 mass% or more, more preferably 95 mass% or more, so that the colloidal solution used as the conductive material exhibits satisfactory electrical conductivity.

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

Generally speaking, metal nanoparticles with a particle size of tens of nanometers have characteristic optical absorption induced by surface plasmon excitation, depending on the metal species. Therefore, it can be confirmed whether or not the metal exists in the form of nanometer-scale fine particles in the solution by measuring the plasmon absorption of the metal colloid solution obtained in the present invention. Furthermore, the average particle size and distribution width can be determined using a transmission electron microscope (TEM) image of the film obtained by casting the solution.

The metal colloid solution obtained in the present invention maintains a long stable dispersion state in all types of media and therefore its use is not limited. The metal colloid solution is used in a variety of fields including catalysts, electronic materials, magnetic materials, optical materials, various sensors, coloring materials, and medical inspection applications. Since the metal species to be contained and the ratio thereof can also be easily adjusted, the effect required for the application can be efficiently exhibited. Moreover, because the solution remains stable for long periods of time, the solution can withstand long-term use and long-term storage, so the solution is very useful. Moreover, the process for preparing the metal colloid solution according to the present invention does not require complicated steps and precise conditions setting, and is therefore a very advantageous industrial process.

Example

The present invention will now be described in more detail by way of example, but the scope of the invention is not limited by the examples. Unless otherwise indicated, "%" means "mass% ".

The equipment and measurement methods used in the following examples are as follows:

^& Lt; ¹ > H-NMR: AL300, manufactured by JEOL Ltd., 300 MHz

Measurement of particle size: FPAR-1000 manufactured by Otsuka Electronics Co., Ltd.

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

Identification of the structure of the protective polymer by ¹ H-NMR

About 3 ml of the protective polymer solution was concentrated and sufficiently dried at reduced pressure. The residue is dissolved in about 0.8 ml of an NMR measurement solvent such as, for example, 0.03% tetramethylsilane-containing deuterated chloroform, and the resulting solution is placed in a glass NMR measurement sample tube having an outer diameter of 5 mm and subjected to nuclear magnetic resonance absorption ¹ H-NMR spectrum was obtained using a spectrum analyzer, Zeol JNM-LA300. The chemical transfer delta was based on the reference tetramethylsilane.

Measurement of particle size by dynamic light scattering

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

Determination of metal content in nonvolatile materials by thermogravimetric analysis

About 1 ml of the metal colloid solution was placed in a glass sample bottle and concentrated by heating in a boiling water bath under a stream of nitrogen. The residue was further vacuum dried at 50 < 0 > C for 8 hours to give a non-volatile material. 2 to 10 mg of nonvolatile material was accurately weighed and placed in an aluminum pan for thermogravimetric analysis. The aluminum pan was placed in an EXSTAR TG / DTA 6300 thermogravimetric / differential thermal analyzer (manufactured by Seiko Instruments Inc.) and heated from room temperature to 500 ° C at a rate of 10 ° C per minute , And the mass loss induced by heating was measured. The silver content in non-volatile materials was calculated according to the following equation:

Metal content (%) = 100 - Weight loss (%)

Measurement of Resistivity of Metal Thin Film Obtained from Metal Colloid Solution

About 0.5 ml of the metal colloid solution was dropped on top of a clean glass plate of 2.5 x 5 cm and a coating film was formed using a bar coater No. 8. The coated film was air-dried and then heated in a hot-air dryer at 125 캜 and 180 캜 for 30 minutes to form a fired film. The thickness of the plastic film was measured using an Optelics C130 Real Color Confocal microscope (manufactured by Lasertec Corporation) and the surface resistance (ohms per square) (JIS) K7194 "4-point probe array using a Loresta-EP MCP-T360 low resistivity meter (manufactured by Mitsubishi Chemical Corporation) Quot; Testing method for resistivity of conductive plastics with a four-point probe array ". The thickness of the coating represents a substantially constant value of 0.3 micrometers under the conditions described above and the volume resistivity (ohm · cm) was calculated from the thickness and surface resistivity (ohms per square) according to the following formula:

Volume resistivity (ohm · centimeter) = surface resistivity (ohms per square) × thickness (cm)

Synthesis Example 1 Synthesis of Tosylated Polyethylene Glycol Monomethyl Ether

A chloroform solution (30 ml) containing 9.6 g (50.0 mmol) of p-toluenesulfonic acid chloride was added to 20.0 g (10.0 mmol) of methoxypolyethylene glycol [Mn = 2,000], 8.0 g And 20 ml of chloroform was added dropwise for 30 minutes while stirring and ice cooling were carried out in parallel. After the addition is complete, the resulting mixture is stirred at 40 < 0 > C for a further 4 hours. After completion of the reaction, 50 ml of chloroform was added to dilute the reaction solution. Subsequently, the diluted reaction solution was washed sequentially with 100 ml of a 5% aqueous hydrochloric acid solution, 100 ml of a saturated aqueous sodium hydrogencarbonate solution and 100 ml of a saturated aqueous sodium chloride solution, dried over magnesium sulfate, filtered and concentrated under reduced pressure. The resulting solid material was washed several times with hexane, filtered and dried at 80 DEG C under reduced pressure. As a result, 22.0 g of a tosylated product was obtained.

The results of ¹ H-NMR (AL300 produced by zeolite, 300 MHz) of the obtained product are as follows:

¹ H-NMR (CDCl ₃₎ Results:

4.2 (t, 2H, J = 4.2 Hz, in the vicinity of the sulfonic ester), 7.3 (d, 2H, J = 7.8, 3.6-3.5 (m, PEGM methylene), 3.4 (s, 3H, methoxy group at the end of the PEGM chain), 2.4 (s, 3H, tosyl group methyl)

Synthesis Example 2: Synthesis of polyethyleneimine-b-polyethylene glycol copolymer

In a nitrogen atmosphere, 19.3 g (9.0 mmol) of the tosylated polyethylene glycol obtained in Synthesis Example 1 and 18.3 g (9.0 mmol) of a branched polyethyleneimine (Epomin (manufactured by Nippon Shokubai Co., Ltd.) EPOMIN SP200) 30.0 g (3.0 mmol) were dissolved at 60 占 폚 and mixed with stirring. To the resultant solution, 0.18 g of potassium carbonate was added and the resulting mixture was stirred at a reaction temperature of 120 캜 for 6 hours. After the reaction was complete, the product was diluted with THF solvent and the residue was removed and then concentrated at 30 < 0 > C under reduced pressure. The obtained solid product was dissolved again in THF solvent and heptane was added to the resultant solution to settle the residue again. The residue was separated 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, 300 MHz, produced by zeolite) and elemental analysis of the resulting product are as follows.

¹ H-NMR (CDCl ₃₎ Results:

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

^{13 C-NMR (DMSO-d} 6) results:

Delta (ppm) = 39.9 (s), 41.8 (s), 47.6 (m), 49.5 (m), 52.6 (m), 54.7 s), 70.5 (m), 71.8 (s) (up to now PEGM methylene and terminal methoxy groups).

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

37.4 g (20 mmol) of EPICLON AM-040-P (bisphenol A epoxy resin, epoxy equivalent: 933, produced by DIC Corporation) and 2.72 g (16 mmol) of 4-phenylphenol were dissolved in N, N -Dimethylacetamide and 0.52 ml of 65% ethyltriphenylphosphonium acetate ethanol solution was added to the resulting solution. The reaction was carried out in a nitrogen atmosphere at 120 < 0 > C for 6 hours. The resulting product was cooled and added dropwise to a large volume of water. The obtained deposit was washed with a large amount of water. The residue was dried under reduced pressure to obtain a modified bisphenol A type epoxy resin. The yield of the product was 98%. The integral ratio of epoxy groups was studied by ¹ H-NMR measurement. It was found that 0.95 epoxy rings per bisphenol A epoxy resin molecule remained and the product was a monofunctional epoxy resin with a bisphenol A skeleton.

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

¹ H-NMR (CDCl ₃₎ Results:

Delta (ppm): 7.55-6.75 (m), 4.40-3.90 (m), 3.33 (m), 2.89 (m), 2.73

To a solution of 20 g (0.8 mmol) of the polyethyleneimine-b-polyethylene glycol copolymer obtained in Synthesis Example 2 in 150 ml of methanol was added a solution of 3.2 g (1.6 mmol) of the modified epoxy resin in acetone (50 ml) And the mixture was stirred at 50 < 0 > C for 2 hours. After the reaction was complete, 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 was 100%.

The results of ¹ H-NMR (AL300 produced by zeolite, 300 MHz) of the obtained product are as follows.

¹ H-NMR (CDCl ₃₎ Results:

(Ppm) = 7.55-6.75 (m), 4.40-3.90 (m), 3.60 (m), 3.25 (s), 2.70-2.40 (m), 1.62

Example 1: Synthesis of protective polymer (1-1)

Acetylation reaction: Synthesis of acetylated compound (1-1A)

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 (Epomin SP200 manufactured by Nippon Shokubai Co., Ltd.) were dissolved in N, N -Dimethylacetamide (270 ml), to which 0.18 g of potassium carbonate was added. The resulting mixture was stirred at a reaction temperature of 120 < 0 > C for 6 hours. After completion of the reaction, the solid material 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 deposit. The precipitate was separated and diluted with THF solvent. The residue was removed and the product was concentrated at 30 < 0 > C under reduced pressure. The obtained solid product was dissolved again in THF solvent, and heptane was added thereto to precipitate the residue again. The residue was separated by filtration and concentrated under reduced pressure. As a result, 47.8 g of pale yellow solid product was obtained (yield: 98%).

The results of ¹ H-NMR and ¹³ C-NMR (AL 300, manufactured by Zeolite, 300 MHz) of the resulting product are as follows.

¹ H-NMR (CDCl ₃₎ Results:

3.25 (s, 3H, the methoxy group at the end of the PEGM chain), 3.16 (m, 2H, methylene group adjacent to acetyl N), 2.65-2.40 (m, Branched PEI ethylene), 1.90 (br s, 3H, acetyl group of first order N).

^{13 C-NMR (DMSO-d} 6) results:

Delta (ppm) = 22.9 (s) (acetyl group of the first class N), 39.9 (s), 41.8 (s), 47.6 (m), 49.5 (m), 52.6 (m), 54.7 59.0 (s), 70.5 (m), 71.8 (s) up to now (PEGM methylene and terminal methoxy groups), 173.4 (m) (acetyl groups).

^{In the 1} H-NMR measurement, it was found that 11 mol% of the primary amine in the branched polyethyleneimine was acetylated by calculating the integral ratio of the 1.90 ppm peak due to the acetylated primary amine in the branched polyethyleneimine.

Oxidation reaction: Synthesis of acetylated N-oxide

37.7 g (N equivalent: 531 mmol) of the acetylated compound (1-1A) obtained by the above-described synthesis example was dissolved in 100 ml of pure water. To the resulting mixture was slowly added 5.16 g (53.1 mmol, 10 mol% as N equivalent) of 35% hydrogen peroxide solution while stirring the mixture in an ice bath and performing the oxidation reaction for 5 hours. A protective polymer (1-1) having a hydrophilic segment and a polyacetylethyleneimine N-oxide chain was quantitatively obtained as a product.

The results of ¹ H-NMR and ¹³ C-NMR (AL 300, manufactured by Zeolite, 300 MHz) of the resulting product are as follows.

^{1 H-NMR (DMSO-d} 6) results:

3.26 (s, 3H, the methoxy group at the end of the PEGM chain), 3.16 (m, 2H, acetyl (meth) acrylate) (Methylene group adjacent to N), 2.9 (m, N-oxide ethylene), 2.7-2.4 (m, branched PEI ethylene), 1.90 (br s, 3H,

^{13 C-NMR (DMSO-d} 6) results:

(Ppm) = 36.0 (m, N-oxide ethylene), 39.0 (m), 41.8 (s), 43.0 (m, N-oxide ethylene), 46.0 ), 53.0 (m), 56.0 (m), 59.0 (s), 63.0-68.0 (m, N-oxide ethylene), 70.0 (m), 71.5 (s), 173.4 (m) (acetyl group).

^{According to 1} H-NMR measurement, the tertiary amine peak at 2.40 to 2.55 ppm, which is on the higher magnetic field side among the branched PEI ethylene at 2.40 to 2.70 ppm, decreased and its integral ratio decreased correspondingly. However, the peak of the secondary amine at 2.55 to 2.60 ppm and the peak of the primary amine at 2.60 to 2.70 ppm were substantially unchanged. ^{From the} results of ¹³ C-NMR measurement, it was also found that the tertiary amine peak at 51.0 to 56.0 ppm was reduced, but the primary and secondary amine peaks at 39.0 to 51.0 ppm were substantially unchanged. Based on the integral ratio of the NMR measurements, it is assumed that about 10% of all nitrogen (N) atoms in the precursor compound are oxidized and converted to N-oxides.

Example 2: Synthesis of protective polymer (1-2)

Oxidation reaction: Synthesis of acetylated N-oxide

37.7 g (N equivalent: 531 mmol) of the acetylated compound (1-1A) obtained in Example 1 was dissolved in 100 ml of pure water. To the resulting mixture was slowly added 25.8 g of a 35% hydrogen peroxide solution (265.5 mmol, 50 mol% as N equivalent), the mixture was stirred in an ice bath and the oxidation reaction was carried out for 5 hours. A protective polymer (1-2) having a hydrophilic segment and a polyacetylethyleneimine N-oxide chain was quantitatively obtained as a product.

The results of ¹ H-NMR and ¹³ C-NMR (AL 300, manufactured by Zeolite, 300 MHz) of the resulting product are as follows.

^{1 H-NMR (DMSO-d} 6) results:

3.26 (s, 3H, the methoxy group at the end of the PEGM chain), 3.16 (m, 2H, acetyl (meth) acrylate) (Methylene group adjacent to N), 2.9 (m, N-oxide ethylene), 2.7-2.5 (m, branched PEI ethylene), 1.90 (br s, 3H,

^{13 C-NMR (DMSO-d} 6) results:

(Ppm) = 36.0 (m, N-oxide ethylene), 39.0 (m), 41.8 (s), 43.0 (m, N-oxide ethylene), 46.0 ), 53.0 (m), 59.0 (s), 63.0-68.0 (m, N-oxide ethylene), 70.0 (m), 71.5 (s), 173.4 (m) (acetyl group).

^{According to 1} H-NMR measurement, the tertiary amine peak at 2.40 to 2.55 ppm, which is on the higher magnetic field side among the branched PEI ethylene at 2.40 to 2.70 ppm, disappeared and the peak of the secondary amine at 2.55 to 2.60 ppm And the peaks of the primary amine at 2.60 to 2.70 ppm decreased and correspondingly the integral ratios decreased. Likewise, in the ¹³ C-NMR measurement, the tertiary amine peak at 51.0 to 56.0 ppm disappeared and the primary and secondary amine peaks at 39.0 to 51.0 ppm decreased. Based on the integral ratio of the NMR measurements, it is assumed that about 50% of all nitrogen (N) atoms in the precursor compound have been oxidized and converted to N-oxides.

Example 3: Synthesis of protective polymer (1-3)

Oxidation reaction: Synthesis of acetylated N-oxide

37.7 g (N equivalent: 531 mmol) of the acetylated compound (1-1A) obtained in Example 1 was dissolved in 100 ml of pure water. To the resulting mixture was slowly added 46.4 g (477.9 mmol, 90 mol% as N equivalent) of 35% hydrogen peroxide solution while stirring the mixture in an ice bath and performing the oxidation reaction for 5 hours. Protective polymer (1-3) having hydrophilic segments and polyacetylethyleneimine N-oxide chain was quantitatively obtained as a product.

The results of ¹ H-NMR and ¹³ C-NMR (AL 300, manufactured by Zeolite, 300 MHz) of the resulting product are as follows.

^{1 H-NMR (DMSO-d} 6) results:

3.26 (s, 3H, the methoxy group at the end of the PEGM chain), 3.16 (m, 2H, acetyl (meth) acrylate) (Methylene group adjacent to N), 2.9 (m, N-oxide ethylene), 2.7-2.6 (m, branched PEI ethylene), 1.90 (br s, 3H,

^{13 C-NMR (DMSO-d} 6) results:

(Ppm) = 36.0 (m, N-oxide ethylene), 39.0 (m), 43.0 (m, N-oxide ethylene), 46.0 (m), 48.0 (m), 53.0 ), 63.0-68.0 (m, N-oxide ethylene), 70.0 (m), 71.5 (s), 173.4 (m) (acetyl group).

^{According to 1} H-NMR measurement, the tertiary amine peak at 2.40 to 2.55 ppm, which is on the higher magnetic field side among the branched PEI ethylene at 2.40 to 2.70 ppm, disappeared and the peak of the secondary amine at 2.55 to 2.60 ppm And the peaks of the primary amine at 2.60 to 2.70 ppm were substantially extinguished. Likewise, in the ¹³ C-NMR measurement, the tertiary amine peak at 51.0 to 56.0 ppm disappeared and the primary and secondary amine peaks at 39.0 to 51.0 ppm disappeared substantially. Based on the integral ratio of the NMR measurements, it is assumed that about 90% of all nitrogen (N) atoms in the precursor compound are oxidized and converted to N-oxides.

Example 4: Synthesis of protective polymer (1-4)

Oxidation reaction: Synthesis of acetylated compound (1-4A)

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 (Epomin SP200 manufactured by Nippon Shokubai Co., Ltd.) were dissolved in N, N -Dimethylacetamide, to which 0.18 g of potassium carbonate was added. The resulting mixture was stirred at a reaction temperature of 140 DEG C for 6 hours. After completion of the reaction, the solid material 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 deposit. The precipitate was separated and diluted with THF solvent. The residue was removed and the product was concentrated at 30 < 0 > C under reduced pressure. The obtained solid product was dissolved again in THF solvent, and heptane was added thereto to precipitate the residue again. The residue was separated 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 (AL 300, manufactured by Zeolite, 300 MHz) of the resulting product are as follows.

¹ H-NMR (CDCl ₃₎ Results:

3.25 (s, 3H, the methoxy group at the end of the PEGM chain), 3.16 (m, 2H, methylene N adjacent to acetyl N), 2.65-2.40 (m, Branched PEI ethylene), 1.90 (br s, 3H, acetyl group of first order N).

^{13 C-NMR (DMSO-d} 6) results:

Delta (ppm) = 22.9 (s) (acetyl group of the first class N), 39.9 (s), 41.8 (s), 47.6 (m), 49.5 (m), 52.6 (m), 54.7 59.0 (s), 70.5 (m), 71.8 (s) up to now (PEGM methylene and terminal methoxy groups), 173.4 (m) (acetyl groups).

^{In the 1} H-NMR measurement, it was found that 30 mol% of the primary amine of the branched PEI ethylene was acetylated by calculating the integral ratio of 1.90 ppm peak due to the acetylated primary amine in the branched polyethyleneimine.

Oxidation reaction: Synthesis of acetylated N-oxide

Except that 39.6 g (N equivalent: 531 mmol) of the acetylated compound (1-4A) obtained by the above-mentioned synthesis example was used instead of 37.7 g of the acetylated compound (1-1A) Acetylated N-oxide was synthesized using the same oxidation reaction. As a result, a protective polymer (1-4) having a hydrophilic segment and a polyacetylethyleneimine N-oxide chain was quantitatively obtained as a product.

¹ H-NMR and ¹³ C-NMR (AL300 produced by zeolite, 300 MHz) of the resulting product were measured, and the same results as those of Example 1 were obtained.

Example 5 Synthesis of Protecting Polymer (1-5)

Oxidation reaction: Synthesis of acetylated N-oxide

Except that 39.6 g (N equivalent: 531 mmol) of the acetylated compound (1-4A) obtained by the above-mentioned synthesis example was used instead of 37.7 g of the acetylated compound (1-1A) in Example 2 Acetylated N-oxide was synthesized using the same oxidation reaction. As a result, a protective polymer (1-5) having a hydrophilic segment and a polyacetylethyleneimine N-oxide chain was quantitatively obtained as a product. ¹ H-NMR and ¹³ C-NMR (AL300 produced by zeolite, 300 MHz) of the resulting product were measured, and the same results as those of Example 2 were obtained.

Example 6: Synthesis of protective polymer (1-6)

Oxidation reaction: Synthesis of acetylated N-oxide

Example 3 was repeated except that 39.6 g (N equivalent: 531 mmol) of the acetylated compound (1-4A) obtained according to the above-mentioned synthesis example was used instead of 37.7 g of the acetylated compound (1-1A) Acetylated N-oxide was synthesized using the same oxidation reaction. As a result, a protective polymer (1-6) having a hydrophilic segment and a polyacetylethyleneimine N-oxide chain was quantitatively obtained as a product. ¹ H-NMR and ¹³ C-NMR (AL 300, manufactured by Zeolite, 300 MHz) of the product were measured, and the same results as those of Example 3 were obtained.

Example 7: Synthesis of protective polymer (1-7)

Acetylation reaction: Synthesis of acetylated compound (1-7A)

9.98 g (N equivalent: 145 mmol) of the acetylated compound (1-4A) (polyethyleneimine-b-polyethylene glycol copolymer in which 30 mol% of primary amine was acetylated) obtained in Example 4 was dissolved in 45 g of chloroform . To the resultant solution, 1.48 g of acetic anhydride was slowly added at 30 DEG C while stirring, and the acetylation reaction was carried out for 2 hours. After completion of the reaction, the product was treated with a strong alkali and the residue thus obtained was filtered. The product was concentrated under reduced pressure to give 10.5 g of a pale yellow solid product (yield: 99%).

The results of ¹ H-NMR and ¹³ C-NMR (AL 300, manufactured by Zeolite, 300 MHz) of the resulting product are as follows.

¹ H-NMR (CDCl ₃₎ Results:

3.25 (s, 3H, the methoxy group at the end of the PEGM chain), 3.16 (m, 2H, methylene group adjacent to acetyl N), 2.65-2.40 (m, Branched PEI ethylene), 2.11 (br s, 3H, acetyl group of the class N), 1.90 (br s, 3H, acetyl group of the class N).

^{13 C-NMR (DMSO-d} 6) results:

(Ppm) = 21.4 (s) (acetyl group of the second class N), 22.9 (s) (acetyl group of the first class N), 39.9 (s), 41.8 (s), 47.6 (m) , 52.6 (m), 54.7 (m), 57.8 (m) (branched PEI ethylene up to this point), 59.0 (s), 70.5 (m), 71.8 173.4 (m) (acetyl group).

By calculating the integral ratios of 1.90 ppm peak and 2.11 ppm peak due to the acetylated primary amine and acetylated secondary amine in the branched polyethyleneimine respectively in ¹ H-NMR measurement, it was found that the ratio of the primary amine in the branched polyethyleneimine 58 mol% and 11 mol% of the secondary amine were acetylated.

Oxidation reaction: Synthesis of acetylated N-oxide

Except that 43.4 g (N equivalent: 531 mmol) of the acetylated compound (1-7A) obtained by the above-mentioned synthesis example was used instead of 37.7 g of the acetylated compound (1-1A) in Example 1 Acetylated N-oxide was synthesized using the same oxidation reaction. The reaction was carried out for 24 hours and a protective polymer (1-7) having a hydrophilic segment and a polyacetylethyleneimine N-oxide chain was obtained as the product. ¹ H-NMR and ¹³ C-NMR (AL 300, manufactured by Zeolite, 300 MHz) of the product were measured, and the same results as those of Example 1 were obtained.

Example 8: Synthesis of protective polymer (1-8)

Oxidation reaction: Synthesis of acetylated N-oxide

Except that 43.4 g (N equivalent: 531 mmol) of the acetylated compound (1-7A) obtained by the above-mentioned synthesis example was used instead of 37.7 g of the acetylated compound (1-1A) in Example 2 Acetylated N-oxide was synthesized using the same oxidation reaction. The reaction was carried out for 24 hours and a protective polymer (1-8) having a hydrophilic segment and a polyacetylethyleneimine N-oxide chain was obtained as the product. ¹ H-NMR and ¹³ C-NMR (AL300 produced by zeolite, 300 MHz) of the product were measured, and the same results as those of Example 2 were obtained.

Example 9 Synthesis of Protecting Polymer (1-9)

Oxidation reaction: Synthesis of acetylated N-oxide

Example 3 was repeated except that 43.4 g (N equivalent: 531 mmol) of the acetylated compound (1-7A) obtained according to the above-mentioned synthesis example was used instead of 37.7 g of the acetylated compound (1-1A) Acetylated N-oxide was synthesized using the same oxidation reaction. The reaction proceeded slowly and took 24 hours. As a result, a protective polymer (1-9) having a hydrophilic segment and a polyacetylethyleneimine N-oxide chain was obtained as a product. ¹ H-NMR and ¹³ C-NMR (AL 300, manufactured by Zeolite, 300 MHz) of the product were measured, and the same results as those of Example 3 were obtained.

Example 10 Synthesis of Protecting Polymer (1-10)

Acetylation reaction: Synthesis of acetylated compound (1-10A)

9.98 g (N equivalent: 145 mmol) of the acetylated compound (1-4A) obtained in Example 4 (30 mol% of the primary amine acetylated PEI ethylene) was dissolved in 45 g of chloroform. To the resulting solution, 2.96 g of acetic anhydride was slowly added at 30 DEG C while stirring and the acetylation reaction was carried out for 2 hours. After completion of the reaction, the product was treated with a strong alkali and the residue thus obtained was filtered. The product was concentrated under reduced pressure, and as a result, 11.0 g of a pale yellow solid product was obtained (yield: 98%).

The results of ¹ H-NMR and ¹³ C-NMR (AL 300, manufactured by Zeolite, 300 MHz) of the resulting product are as follows.

¹ H-NMR (CDCl ₃₎ Results:

3.25 (s, 3H, the methoxy group at the end of the PEGM chain), 3.16 (m, 2H, methylene group adjacent to acetyl N), 2.65-2.40 (m, Branched PEI ethylene), 2.11 (br s, 3H, acetyl group of the class N), 1.90 (br s, 3H, acetyl group of the class N).

^{13 C-NMR (DMSO-d} 6) results:

(Ppm) = 21.4 (s) (acetyl group of the second class N), 22.9 (s) (acetyl group of the first class N), 39.9 (s), 41.8 (s), 47.6 (m) , 52.6 (m), 54.7 (m), 57.8 (m) (branched PEI ethylene up to this point), 59.0 (s), 70.5 (m), 71.8 173.4 (m) (acetyl group).

By calculating the integral ratios of 1.90 ppm peak and 2.11 ppm peak due to the acetylated primary amine and acetylated secondary amine in the branched polyethyleneimine respectively in ¹ H-NMR measurement, it was found that the ratio of the primary amine in the branched polyethyleneimine 88 mol% and 22 mol% of the secondary amine were acetylated.

Oxidation reaction: Synthesis of acetylated N-oxide

Example 1 was repeated except that 47.4 g (N equivalent: 531 mmol) of the acetylated compound (1-10A) obtained according to the above-mentioned synthesis example was used instead of 37.7 g of the acetylated compound (1-1A) Acetylated N-oxide was synthesized using the same oxidation reaction. The reaction proceeded slowly and took 72 hours. As a result, a protective polymer (1-10) having a hydrophilic segment and a polyacetylethyleneimine N-oxide chain was obtained as a product. ¹ H-NMR and ¹³ C-NMR (AL 300, manufactured by Zeolite, 300 MHz) of the product were measured, and the same results as those of Example 1 were obtained.

Example 11: Synthesis of protective polymer (1-11)

Oxidation reaction: Synthesis of acetylated N-oxide

Example 2 was repeated except that 47.4 g (N equivalent: 531 mmol) of the acetylated compound (1-10A) obtained according to the above-mentioned synthesis example was used instead of 37.7 g of the acetylated compound (1-1A) Acetylated N-oxide was synthesized using the same oxidation reaction. The reaction was carried out for 72 hours and a protective polymer (1-11) having a hydrophilic segment and a polyacetylethyleneimine N-oxide chain was obtained as the product. ¹ H-NMR and ¹³ C-NMR (AL300 produced by zeolite, 300 MHz) of the product were measured, and the same results as those of Example 2 were obtained.

Example 12: Synthesis of protective polymer (1-12)

Oxidation reaction: Synthesis of acetylated N-oxide

Example 3 was repeated except that 47.4 g (N equivalent: 531 mmol) of the acetylated compound (1-10A) obtained according to the above-mentioned synthesis example was used instead of 37.7 g of the acetylated compound (1-1A) Acetylated N-oxide was synthesized using the same oxidation reaction. The reaction proceeded slowly and took 120 hours. As a result, a protective polymer (1-12) having a hydrophilic segment and a polyacetylethyleneimine N-oxide chain was obtained as a product. ¹ H-NMR and ¹³ C-NMR (AL 300, manufactured by Zeolite, 300 MHz) of the product were measured, and the same results as those of Example 3 were obtained.

COMPARATIVE EXAMPLE 1 Synthesis of Protecting Polymer (1 ')

Acetylation reaction: Synthesis of acetylated compound (1'-A)

9.98 g (N equivalent: 145 mmol) of the acetylated compound (1-4A) (polyethyleneimine-b-polyethylene glycol copolymer in which 30 mol% of primary amine was acetylated) obtained in Example 4 was dissolved in 45 g of chloroform . To the resulting solution, 7.40 g of acetic anhydride was slowly added at 30 DEG C while stirring, and the acetylation reaction was carried out for 2 hours. After completion of the reaction, the product was treated with a strong alkali and the residue thus obtained was filtered. The product was concentrated under reduced pressure to give 12.0 g of a pale yellow solid product (yield: 92%).

The results of ¹ H-NMR and ¹³ C-NMR (AL 300, manufactured by Zeolite, 300 MHz) of the resulting product are as follows.

¹ H-NMR (CDCl ₃₎ Results:

3.25 (s, 3H, the methoxy group at the end of the PEGM chain), 3.16 (m, 2H, methylene group adjacent to acetyl N), 2.65-2.40 (m, Branched PEI ethylene), 2.11 (br s, 3H, acetyl group of the class N), 1.90 (br s, 3H, acetyl group of the class N).

^{13 C-NMR (DMSO-d} 6) results:

(Ppm) = 21.4 (s) (acetyl group of the second class N), 22.9 (s) (acetyl group of the first class N), 39.9 (s), 41.8 (s), 47.6 (m) , 52.6 (m), 54.7 (m), 57.8 (m) (branched PEI ethylene up to this point), 59.0 (s), 70.5 (m), 71.8 173.4 (m) (acetyl group).

By calculating the integral ratios of 1.90 ppm peak and 2.11 ppm peak due to the acetylated primary amine and acetylated secondary amine in the branched polyethyleneimine respectively in ¹ H-NMR measurement, it was found that the ratio of the primary amine in the branched polyethyleneimine 96 mol% and 98 mol% of the secondary amine were acetylated.

Oxidation reaction: Synthesis of acetylated N-oxide

Except that 55.7 g (N equivalent: 531 mmol) of the acetylated compound (1'-A) obtained by the above-mentioned synthesis example was used instead of 37.7 g of the acetylated compound (1-1A) Acetylated N-oxides were synthesized using the same oxidation reaction as in Example 1. < tb >< TABLE > The reaction proceeded slowly and took 120 hours. The resulting product was applied to ¹ H-NMR and ¹³ C-NMR measurements (AL 300, 300 MHz, produced by Zeolite) and the results showed that a small amount of the target acetylate N-oxide was obtained.

Example 13: Synthesis of protective polymer (2-1)

Synthesis of acetylated compound (2-1A)

To a methanol (150 ml) solution of 18.2 g (1.25 mmol) of the acetylated compound (1-4A) obtained in Example 4 (30 mol% of the primary amine acetylated with PEI ethylene) (50 ml) of 3.2 g (1.6 mmol) of a modified epoxy resin having a bisphenol A skeleton synthesized in Example 1 was added dropwise in a nitrogen atmosphere, and stirring was carried out at 50 DEG C for 2 hours. After completion of the reaction, the solvent was distilled off under reduced pressure and the residue was vacuum-dried. As a result, a polyacetylethyleneimine-b-polyethylene glycol-b-bisphenol A type epoxy resin was obtained. The yield was 100%.

The results of ¹ H-NMR (AL300 produced by zeolite, 300 MHz) of the resulting product are as follows.

¹ H-NMR (CDCl ₃₎ Results:

(Ppm) = 7.55-6.75 m, 4.40-3.90 m, 3.57 (br s, PEGM methylene), 3.33 (m), 3.25 (s, 3H, the methoxy group at the end of the PEGM chain), 3.16 (m, 2H, methylene group adjacent to acetyl N), 2.89 (m), 2.73 (m), 2.65-2.40 (m, branched PEI ethylene), 1.90 (br s, 3H, 1.62 (s).

^{In the 1} H-NMR measurement, it was found that 30 mol% of the primary amine of the branched polyethyleneimine was acetylated by calculating the integral ratio of the 1.90 ppm peak of the acetylated primary amine in the branched polyethyleneimine.

Oxidation reaction: Synthesis of acetylated N-oxide

Except that 43.9 g (N equivalent: 531 mmol) of the acetylated compound (2-1A) obtained according to the above-mentioned synthesis example was used instead of 37.7 g of the acetylated compound (1-1A) in Example 2 Acetylated N-oxide was synthesized using the same oxidation reaction. As a result, a protective polymer (2-1) having a hydrophilic segment, a hydrophobic segment, and a polyacetylethyleneimine N-oxide chain was quantitatively obtained as a product.

The results of ¹ H-NMR of the resulting product are as follows.

^{1 H-NMR (DMSO-d} 6) results:

(Ppm) = 7.55-6.75 (m), 4.40-3.90 (m), 3.6 (m, PEGM methylene), 3.30-3.20 (m, N-oxide ethylene), 3.25 (Methylene group adjacent to acetyl N), 2.9 (m, N-oxide ethylene), 2.73 (m), 2.65-2.40 (m, branched PEI ethylene), 1.90 , 3H, acetyl group of primary N), 1.62 (s).

^{According to 1} H-NMR measurement, the tertiary amine peak at 2.40 to 2.55 ppm, which is at the higher magnetic field side among the branched PEI ethylene at 2.40 to 2.65 ppm, disappeared and the peak of the secondary amine at 2.55 to 2.60 ppm And the peaks of the primary amine at 2.60 to 2.70 ppm decreased and correspondingly the integral ratios decreased. Based on the integral ratio of the NMR measurements, it is assumed that about 50% of all nitrogen (N) atoms in the precursor compound have been oxidized and converted to N-oxides.

Example 14: Synthesis of silver colloid solution using protective polymer (1-1) of Example 1

180 g of pure water, 13.5 g of the aqueous solution of the protective polymer (1-1) obtained in Example 1, and 113 g (1.27 mol) of N, N-dimethylaminoethanol were added in succession to a 1 L reactor and stirred , A mixed solution of a protective polymer and a reducing agent was prepared. In a separate vessel, 72.0 g (0.424 mol) of silver nitrate was dissolved in 120 g of pure water. The resulting nitric acid silver solution was added dropwise to the reactor at room temperature for about 30 minutes and the mixture was stirred at 40 < 0 > C for 4 hours. After completion of the reaction and cooling, 1.4 L of acetone as a poor solvent (about 3 times the volume of the reaction mixture) was added thereto, and the resulting mixture was stirred for 5 minutes and allowed to stand for about 1 hour. As a result, the silver nanoparticles and the complex constituted by the protective polymer were separated by sedimentation. After removing the supernatant, the resulting supernatant was separated by centrifugation. The separated paste-like deposits were washed with 80 g of pure water and thoroughly dispersed. The remaining acetone was distilled off. The product was concentrated at reduced pressure until the nonvolatile content was about 60%. As a result, aqueous solution obtained 77.0 g of a colloidal solution (46.2 g as a nonvolatile material, yield: 96%). From the results of thermal analysis (Tg / DTA), it was found that the silver content in the nonvolatile material was 96.3%.

Example 15: Synthesis of silver colloid solution using protective polymer (1-2) of Example 2

In this example, except that 13.7 g of the aqueous solution of the protective polymer (1-1) obtained in Example 1 was used instead of 14.7 g of the aqueous solution of the protective polymer (1-2) obtained in Example 2, As in 14, 76.0 g of an aqueous silver colloidal solution having a nonvolatile content of about 60% (45.5 g as a nonvolatile material, yield: 95%) was obtained. From the results of thermal analysis (Tg / DTA), it was found that the silver content in the nonvolatile material was 96.2%.

Example 16: Synthesis of silver colloid solution using protective polymer (1-3) of Example 3

In this example, except that 15.9 g of the aqueous solution of the protective polymer (1-3) obtained in Example 3 was used instead of 13.5 g of the aqueous solution of the protective polymer (1-1) obtained in Example 1, As in 14, 76.7 g of an aqueous silver silver colloid solution having a nonvolatile content of about 60% (46.0 g as a nonvolatile material, yield: 95.8%) was obtained. From the results of the thermal analysis (Tg / DTA), it was found that the silver content in the nonvolatile material was 95.8%.

Example 17: Synthesis of silver colloid solution using protective polymer (1-4) of Example 4

In this example, except that 14.2 g of the aqueous solution of the protective polymer (1-4) obtained in Example 4 was used instead of 13.5 g of the aqueous solution of the protective polymer (1-1) obtained in Example 1, As in 14, 76.8 g of an aqueous silver silver colloid solution having a nonvolatile content of about 60% (46.1 g as a nonvolatile material, yield: 96%) was obtained. From the results of thermal analysis (Tg / DTA), it was found that the silver content in the nonvolatile material was 96.2%.

Example 18: Synthesis of silver colloid solution using protective polymer (1-5) of Example 5

In this example, except for using 15.3 g of the aqueous solution of the protective polymer (1-5) obtained in Example 5 instead of 13.5 g of the aqueous solution of the protective polymer (1-1) obtained in Example 1, As in 14, 76.0 g of an aqueous silver silver colloid solution having a nonvolatile content of about 60% (45.6 g as a nonvolatile material, yield: 95%) was obtained. From the results of thermal analysis (Tg / DTA), it was found that the silver content in the nonvolatile material was 96.4%.

Example 19: Synthesis of silver colloid solution using protective polymer (1-6) of Example 6

In this example, except that 16.5 g of the aqueous solution of the protective polymer (1-6) obtained in Example 6 was used instead of 13.5 g of the aqueous solution of the protective polymer (1-1) obtained in Example 1, As in 14, 76.0 g of an aqueous silver silver colloid solution having a nonvolatile content of about 60% (45.6 g as a nonvolatile material, yield: 95%) was obtained. From the results of the thermal analysis (Tg / DTA), it was found that the silver content in the nonvolatile material was 95.9%.

Example 20: Synthesis of silver colloid solution using protective polymer (1-7) of Example 7

In this example, except for using 15.5 g of the aqueous solution of the protective polymer (1-7) obtained in Example 7 instead of 13.5 g of the aqueous solution of the protective polymer (1-1) obtained in Example 1, As in 14, 76.0 g of an aqueous silver silver colloid solution having a nonvolatile content of about 60% (45.6 g as a nonvolatile material, yield: 95%) was obtained. From the results of thermal analysis (Tg / DTA), it was found that the silver content in the nonvolatile material was 96.1%.

Example 21: Synthesis of silver colloid solution using protective polymer (1-8) of Example 8

In this example, except that 16.7 g of the aqueous solution of the protective polymer (1-8) obtained in Example 8 was used instead of 13.5 g of the aqueous solution of the protective polymer (1-1) obtained in Example 1, As in 14, 76.0 g of an aqueous silver silver colloid solution having a nonvolatile content of about 60% (45.6 g as a nonvolatile material, yield: 95%) was obtained. From the results of thermal analysis (Tg / DTA), it was found that the silver content in the nonvolatile material was 96.4%.

Example 22: Synthesis of silver colloid solution using protective polymer (1-9) of Example 9

In this example, except that 17.8 g of the aqueous solution of the protective polymer (1-9) obtained in Example 9 was used instead of 13.5 g of the aqueous solution of the protective polymer (1-1) obtained in Example 1, As in 14, 76.0 g of an aqueous silver silver colloid solution having a nonvolatile content of about 60% (45.6 g as a nonvolatile material, yield: 95%) was obtained. From the results of the thermal analysis (Tg / DTA), it was found that the silver content in the nonvolatile material was 95.9%.

Example 23: Synthesis of silver colloid solution using protective polymer (1-10) of Example 10

In this example, except that 16.9 g of the aqueous solution of the protective polymer (1-10) obtained in Example 10 was used instead of 13.5 g of the aqueous solution of the protective polymer (1-1) obtained in Example 1, As in 14, 75.1 g of an aqueous silver colloidal solution with a nonvolatile content of about 60% (45.1 g as a nonvolatile material, yield: 94%) was obtained. From the results of thermal analysis (Tg / DTA), it was found that the silver content in the nonvolatile material was 96.1%.

Example 24: Synthesis of silver colloid solution using protective polymer (1-11) of Example 11

In this example, except that 18.1 g of the aqueous solution of the protective polymer (1-11) obtained in Example 11 was used instead of 13.5 g of the aqueous solution of the protective polymer (1-1) obtained in Example 1, As in 14, 74.3 g of an aqueous silver silver colloid solution having a nonvolatile content of about 60% (44.6 g as a nonvolatile material, yield: 93%) was obtained. From the results of the thermal analysis (Tg / DTA), it was found that the silver content in the nonvolatile material was 95.9%.

Example 25: Synthesis of silver colloid solution using protective polymer (1-12) of Example 12

In this example, except that 19.3 g of the aqueous solution of the protective polymer (1-12) obtained in Example 12 was used instead of 13.5 g of the aqueous solution of the protective polymer (1-1) obtained in Example 1, As in 14, 76.0 g of an aqueous silver silver colloid solution having a nonvolatile content of about 60% (45.6 g as a nonvolatile material, yield: 95%) was obtained. From the results of thermal analysis (Tg / DTA), it was found that the silver content in the nonvolatile material was 96.1%.

Example 26: Synthesis of silver colloid solution using protective polymer (2-1) of Example 13

In this example, except that 15.7 g of the aqueous solution of the protective polymer (2-1) obtained in Example 13 was used instead of 13.5 g of the aqueous solution of the protective polymer (1-1) obtained in Example 1, As in 14, 75.2 g of an aqueous silver colloidal solution with a nonvolatile content of about 60% (45.1 g as a nonvolatile material, yield: 94%) was obtained. From the results of thermal analysis (Tg / DTA), it was found that the silver content in the nonvolatile material was 95.6%.

Comparative Example 2: Synthesis of a silver colloid solution using the protective polymer (1 ') of Comparative Example 1

In this example, except for using 21.0 g of the aqueous solution of the protective polymer (1 ') obtained in Comparative Example 1 instead of 13.5 g of the aqueous solution of the protective polymer (1-1) obtained in Example 1, As in 14, 77.6 g of an aqueous silver colloidal solution with a nonvolatile content of about 60% (46.6 g as a nonvolatile material, yield: 97%) was obtained. From the results of thermal analysis (Tg / DTA), it was found that the silver content in the nonvolatile material was 95.5%.

Comparative Example 3: Synthesis of silver colloid solution using the compound of Synthesis Example 2

In this example, 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 protective polymer (1-1) obtained in Example 1 76.0 g of an aqueous silver colloidal solution having a nonvolatile content of about 60% (45.6 g as a nonvolatile material, yield: 95%) was obtained, as in Example 14, From the results of thermal analysis (Tg / DTA), it was found that the silver content in the nonvolatile material was 96.2%.

Comparative Example 4: Synthesis of silver colloid solution using the compound of Synthesis Example 3

In this example, an aqueous solution prepared by dissolving 4.1 g of the precursor compound obtained in Synthesis Example 3 in 9.5 g of pure water was used in place of 13.5 g of the aqueous solution of the protective polymer (1-1) obtained in Example 1 , 76.8 g of an aqueous silver colloidal solution having a nonvolatile content of about 60% (46.1 g as a nonvolatile material, yield: 96%) was obtained as in Example 14. From the results of the thermal analysis (Tg / DTA), it was found that the silver content in the nonvolatile material was 95.8%.

The acetylation rates of the primary and secondary amines obtained by applying the protective polymers of Examples 1 to 13 and Comparative Example 1 to NMR measurements are shown in Table 1 and the N-oxidation rates resulting from the oxidation reactions. The silver colloid solutions obtained in Examples 14 to 26 and Comparative Examples 2 to 4 were used to measure the resistance and average particle size of the metal foil as described above. The amount of acetone used in the sedimentation process during synthesis and the time spent in the treatment are shown in Table 3. [ The obtained silver colloidal solution was allowed to stand at room temperature (25 to 35 DEG C) for one week and its stability was evaluated through the appearance of the solution. The results are shown in Tables 2 and 3. In Table 2, O.L. means the measurement range is exceeded.

From the results, it can be seen that the protection with a primary amine in the polyalkyleneimine segment of 5 to 95 mol% and / or an acetylation rate of secondary amine of 5 to 50 mol% and an N-oxidation rate of 0.5 to 95% In the case of using a polymer, it can be seen that excellent electrical conductivity, dispersion stability, and easiness of purification and separation appear.

<Table 1>

In the case of the protective polymer of Comparative Example 1 (primary acetylation rate: 96%, secondary acetylation rate: 98%), the oxidation reaction was carried out for a long time, i.e. 120 hours, . As a result of NMR measurement, it was found that the N-oxidation rate was 5% or less and N-oxydation did not proceed in the polymer having a high acetal conversion ratio as in Comparative Example 1. [

<Table 2>

<Table 3>

Claims (13)

5 to 95 mol% of the primary amine in the polyalkyleneimine is acetylated or 5 to 95 mol% of the primary amine in the polyalkyleneimine and 5 to 50 mol% of the secondary amine are acetylated, (A) a polyacetyl alkyleneimine N-oxide segment wherein 0.5 to 95 mol% of the total number of nitrogen atoms in the Reneimin is oxidized; And the hydrophilic segment (B)
In the molecule. The metal nanoparticle-protective polymer of claim 1, further comprising a hydrophobic segment (C) in the molecule. 3. The metal nanoparticle-protective polymer according to claim 1 or 2, wherein the hydrophilic segment (B) comprises a polyoxyalkylene chain. The metal nanoparticle-protective polymer according to claim 2 or 3, wherein the hydrophobic segment (C) comprises a structure derived from an epoxy resin. 5. The metal nanoparticle-protective polymer according to any one of claims 1 to 4, wherein the number of alkyleneimine units in the polyacetylalkyleneimine N-oxide segment (A) is in the range of 5 to 2,500. 6. The metal nanoparticle-protective polymer according to any one of claims 1 to 5, having a weight-average molecular weight in the range of 1,000 to 100,000. Polymerizing a compound having a polyalkyleneimine segment and a compound having a hydrophilic segment (B) and acetylating the alkyleneimine unit with an acetylating agent to obtain a polymer;
Oxidizing agents to oxidize polymers
Wherein the metal nanoparticle-protecting polymer is a metal nanoparticle. Preparing a compound having a polyalkyleneimine segment and a hydrophilic segment (B) in the molecule as a precursor;
Acetylating the alkylene imine unit by acetylating the precursor using an acetylating agent;
Oxidizing the resulting acetylated product with an oxidizing agent
Wherein the metal nanoparticle-protecting polymer is a metal nanoparticle. medium; And
The complexes dispersed in the medium
Wherein each composite is comprised of metal nanoparticles and a metal nanoparticle-protective polymer that protects the metal nanoparticles,
The metal nanoparticle-protective polymer may be prepared by acetylating 5 to 95 mol% of the primary amine in the polyalkyleneimine or by reacting 5 to 95 mol% of the primary amine in the polyalkyleneimine and 5 to 50 mol% % Acetylated and 0.5 to 95 mol% of the total number of nitrogen atoms in the polyalkyleneimine is oxidized, and a hydrophilic segment (B).
Metal colloid solution. The metal colloid solution according to claim 9, wherein the metal nanoparticles are silver nanoparticles. 11. The metal colloid solution according to claim 9 or 10, wherein the metal nanoparticles have a particle size in the range of 5 to 50 nm. 5 to 95 mol% of the primary amine in the polyalkyleneimine is acetylated or 5 to 95 mol% of the primary amine in the polyalkyleneimine and 5 to 50 mol% of the secondary amine are acetylated, (A) in which 0.5 to 95 mol% of the total number of nitrogen atoms in the R-imine is oxidized, and the presence of a metal nanoparticle-protective polymer containing the hydrophilic segment (B) in the molecule , Reducing metal ions to metal nanoparticles in the medium
&Lt; / RTI &gt; 13. The method for producing a metal colloid solution according to claim 12, wherein the metal nanoparticles are silver nanoparticles.