WO2002094953A1 - Colloidal alcohol solution of noble metal or copper, process for producing the same, and coating composition - Google Patents

Abstract

An alcohol solution which contains colloidal particles of a noble metal or copper and a high-molecular pigment dispersant and which has a high concentration and sufficient colorability and is suitable for use in the sol-gel method, characterized in that the alcohol has one to four carbon atoms and the high-molecular pigment dispersant satisfies the following relationship (1) or (2): (1) A ≥ 3 ml and 3 ml ≤ B ≤ 40 ml (2) 0.25 ≤ A/B ≤ 4.5 wherein A and B are the amounts of water and hexane, respectively, necessary for making turbid an acetone solution obtained by dissolving 0.5 g of the high-molecular pigment dispersant in 10 ml of acetone.

Description

 Specification

Alcohol solution of noble metal or copper colloid, method for producing the same, and composition for coating

 The present invention relates to an alcohol solution of a noble metal or copper colloid which can be suitably used for a sol-gel method, a method for producing the same, a solution preparation method, a coating composition using the same, an inorganic coating using the same, The present invention relates to a method for forming an inorganic film. Background art

 Precious metal and copper colloids are very stable chemically and develop a unique color for each colloid. For example, colloidal gold exhibits a color such as blue, bluish violet, or magenta depending on the particle size. Taking advantage of this property, it has been used for coloring Venetian glass and stained glass. Such color development by the noble metal colloid is observed in so-called nanoparticles having a particle size of several nm to several tens nm, and it is advantageous that the colorant is a colloid having a narrow particle size distribution.

 Japanese Patent Application Laid-Open No. 11-080647 discloses a precious metal or copper colloidal particle having high coloring properties, which includes a precious metal or copper colloidal particle and a high molecular weight pigment dispersant. A copper colloid solution is disclosed. Since this material is not intended for use as an optical material, the necessary saturation may not be obtained in some cases.

On the other hand, the sol-gel method for producing glass and ceramics has been known for a long time. In the sol-gel method, usually, an alcohol, water necessary for hydrolysis, an acid or a base as a catalyst are added to a metal alkoxide, and the mixture is subjected to polycondensation to form a sol in which particles of a metal oxide formed are dispersed in a colloidal state. When this is further gelled, it is processed into a coating film or the like, and an oxide solid is obtained by heating. The sol-gel method has the advantage of obtaining a thin film gel or glass from a solution as described above.In addition, the thin film obtained by this method has good adhesion to a glass substrate and uniformity of the obtained thin film. It also has the advantage of improving chemical and physical properties such as heat resistance, corrosion resistance, chemical resistance and mechanical strength of the substrate. In recent years, functional properties such as optical functions such as dimming and coloring and electric functions have been imparted to the obtained coating film. If a large amount of the precious metal or copper colloidal solution is added to the metal alkoxide solution used in this sol-gel method, mixing with a water-insoluble organic solvent as a dispersion medium will not be sufficient, and the desired coating will not be achieved. Agent cannot be obtained. On the other hand, when water is used as the dispersion medium, the water concentration becomes too high, so that hydrolysis of the metal alkoxide is promoted more than necessary, and the stability of the coating agent decreases. Summary of the Invention

 In view of the above, the present invention provides a colloidal alcohol solution of a noble metal or copper which has a high concentration, has sufficient coloring properties, and can be suitably used for a sol-gel method, and a method for producing the same, a method for preparing a solution, and It is an object of the present invention to provide a coating composition comprising the alcohol solution of a noble metal or copper colloid or a colloidal solution of a noble metal or copper, and an inorganic coating and an inorganic coating forming method using the same. It is a thing.

 The present inventors have used an alcohol having 1 to 4 carbon atoms as a dispersion medium of a noble metal or copper colloid, and considered the affinity with the above alcohol as a protective colloid of the noble metal or copper colloid particles. By selecting a specific high molecular weight pigment dispersant, an alcohol solution of a precious metal or copper colloid having a narrow particle size distribution of the colloid particles can be obtained at a high concentration, and it can be suitably used for the sol-gel method. The present invention has been completed.

That is, the present invention is an alcohol solution of a noble metal or copper colloid comprising a noble metal or copper colloid particle and a high molecular weight pigment dispersant, wherein the alcohol has 1 to 4 carbon atoms, and the high molecular weight pigment dispersion agent is an alcohol solution of a colloid of a noble metal or copper, characterized in that those that meet the following formula (1) or (2) _c

(1) A 3 m 1 and 3 m 1≤B≤ 4 O m 1

(2) 0.25≤A / B≤4.5 (Wherein A and B are respectively the values of the above-mentioned acetone solution in which 0.5 g of the high molecular weight pigment dispersant is dissolved in 10 ml of acetone and water or hexane is added until the acetone solution becomes cloudy. The addition amount (ml) of the water and the addition amount (ml) of the hexane until the aceton solution becomes cloudy. ]

 The alcohol is preferably a monoalcohol having 2 to 4 carbon atoms, and the above formula (1) is preferably the following formula (1 ′).

 (1 ') A≥ 10m 1 and 4 m 1 2 Ora 1

 The present invention further provides a noble metal or copper colloid alcohol which is prepared by dissolving a noble metal or copper compound into an alcohol having 1 to 4 carbon atoms, adding a high molecular weight pigment dispersant, and then reducing the compound to a noble metal or copper. A method for producing a solution, wherein the high molecular weight pigment dispersant satisfies the following formula (1) or (2): a method for producing an alcohol solution of a noble metal or copper colloid.

 (1) A≥ 3 m 1 and 3 1 B≤ 40 m 1

 (2) 0.25≤A / B≤4.5

 (In the formula, A and B are respectively the same as above when water or hexane is added to an acetone solution obtained by dissolving 0.5 g of the polymer i pigment dispersant in 10 ml of acetone until the acetone solution becomes cloudy. The amount (ml) of the water added and the amount (ml) of the hexane added until the aceton solution became cloudy. ]

 The present invention is also a colloidal alcohol solution of a noble metal or copper obtained by this method.

 The present invention is characterized in that, after concentrating an alcohol solution of a colloid of a noble metal or copper obtained by the above-mentioned production method, a solution different from the above-mentioned alcohol is added to a solution obtained by concentrating the solution to dilute the noble metal or copper. This is a method for preparing a colloid solution. The present invention is also a colloidal solution of a noble metal or copper obtained by this preparation method.

 The present invention is also a coating composition comprising the above alcohol solution of a noble metal or copper colloid and a metal alkoxide.

The present invention comprises the above colloidal solution of a noble metal or copper and a metal alkoxide. It is also a coating composition.

 The present invention is also an inorganic coating obtained using the coating composition. The present invention further provides a method for forming an inorganic film, comprising forming an inorganic film on a substrate using the coating composition. Detailed Disclosure of the Invention

 Hereinafter, the present invention will be described in detail.

 The alcohol solution of the noble metal or copper colloid of the present invention contains noble metal or copper colloid particles and a high molecular weight pigment dispersant, and has a C 1-4 alcohol as a dispersion medium. When the alcohol has 1 to 4 carbon atoms, not only can noble metal or copper color particles be dispersed with high concentration and high stability, but also when used as an optical material, In addition, a high chroma can be realized, and a large amount of the colloidal alcohol solution of the noble metal or copper of the present invention can be used in the sol-gel method.

 When the carbon number is 5 or more, the noble metal or copper colloid solution using the alcohol as a solvent has insufficient compatibility with the metal alkoxide solution used in the sol-gel method, and a coating composition may be obtained. It may not be possible. The alcohol used in the present invention is not particularly limited as long as it has 1 to 4 carbon atoms. For example, monoalcohols such as methanol, ethanol, propanol, and ptananol; ethylene glycol, diethylene glycol, and propylene glycol And alkylene glycol monoalkyl ethers such as ethylene glycol monomethyl enoate ether, ethylene glycol monoethyl enolate ether, and propylene dalycol monomethynoole ether.

When the colloidal alcohol solution of the noble metal or copper of the present invention is used in the sol-gel method, it is preferably one having 2 to 4 carbon atoms in consideration of the evaporability, and it does not progress cross-linking between metal alkoxides. Considering this, monoalcohols are preferred. Since ethyl silicate is preferably used as the metal alkoxide in the sol-gel method, the alcohol is more preferably ethanol. In addition, The above alcohols may be used alone or in combination of two or more.

 Considering the use of a large amount in the sol-gel method, it is preferable to use a dispersion medium of the noble metal or copper colloid composed of only the alcohol. However, if the solubility of the raw material is not sufficient with the alcohol alone, a small amount of the above alcohol may be used as long as the stability is not impaired when added to the metal alkoxide solution used in the sol-gel method. Water may be added.

 In the present invention, the noble metal or copper colloid particles are formed of a noble metal or copper compound.

 The noble metal is not particularly limited, and examples thereof include gold, silver, ruthenium, rhodium, palladium, osmium, iridium, and platinum. Of these, gold, silver, platinum and palladium are preferred.

 The noble metal or copper compound is preferably a compound which dissolves in the above alcohol having 1 to 4 carbon atoms. Examples thereof include tetrachlorobase (III) acid tetrahydrate, silver perchlorate, and hexachlorotoplatinum (IV). Acid hexahydrate, palladium (II) chloride dihydrate, rhodium (III) trichloride trihydrate, copper (II) chloride dihydrate, copper (II) acetate monohydrate and the like be able to. It is also possible to use those which can be dissolved in an alcohol having 1 to 4 carbon atoms to which a small amount of water has been added, such as potassium tetrachloride (III) potassium dihydrate and copper sulfate (II). One or more of these can be used.

 In the present invention, the high molecular weight pigment dispersant is an amphiphilic copolymer in which a functional group having a high affinity for the pigment surface is introduced into the high molecular weight polymer. This is suitable as a dispersant for organic pigments or inorganic pigments because it has sufficient compatibility with resin compositions for coatings, etc., and is usually used as a pigment dispersant in the production of pigment pastes. Is what it is.

 In the present invention, the high-molecular weight pigment dispersant functions as a protective colloid when the noble metal or copper colloid particles are formed, and by using the same, a very high concentration alcohol solution of the noble metal or copper colloid is obtained. Can be

The high molecular weight pigment dispersant satisfies the following formula (1) or (2). (1) A≥ 3 m 1 and 3m 1≤B 4 Om 1

 (2) 0.2 5 ≤ A / B ≤ 4.5

 (Wherein A and B are respectively the same as above until the acetone solution becomes cloudy when water or hexane is added to an acetone solution in which 0.5 g of the high molecular weight pigment dispersant is dissolved in 10 ml of acetone. The addition amount (ml) of the water and the addition amount (ml) of the hexane until the aceton solution becomes cloudy. ]

 In the present invention, even if the formula (1) is not satisfied, the formula (2) can be used as the high molecular weight pigment dispersant if the formula (2) is satisfied. If the above A and B are not included in either of the formulas (1) and (2), the high molecular weight pigment dispersant is an alcohol having 1 to 4 carbon atoms, which is a dispersion medium of an alcohol solution of a noble metal or copper colloid. As a result, no colloidal particles of noble metal or copper can be obtained.

 Here, the above formula (1) is preferably the following formula (1 ′).

 (1 ') A 1 Om 1 and 4m 1≤B≤ 2 Om 1

 By using a high molecular weight pigment dispersant satisfying the above formula (1) or formula (2), it is possible to disperse the noble metal or copper colloid particles stably and at a high concentration. In addition, since the absorption curve of the alcohol solution of colloidal particles of noble metal or copper is sharper than before, it can be used as a material with excellent optical properties. The number average molecular weight of the high molecular weight pigment dispersant used in the present invention is preferably from 1,000 to 100,000. If it is less than 1000, the dispersion stability is not sufficient, and if it exceeds 1,000,000, the viscosity becomes too high to make handling difficult, and the particle size distribution of the colloid particles becomes wide and the chroma decreases. More preferably, it is 2000 to 500,000, and still more preferably 4000 to 500,000.

 The high molecular weight pigment dispersant is a resin having a structure containing a pigment affinity group and a solvation portion, and examples thereof include those exemplified in JP-A-11-80647.

As the high molecular weight pigment dispersant, a commercially available pigment dispersant can also be used. Examples of the above commercially available products include Solsperse 27,000 and Solsperse 41 090 (above, manufactured by Abyssia), Dispervik 180, Dispervik 181, Dispervik 190, Dispervik 191, Dispervik 192 (above, manufactured by Big Chem), Polymer 450, Polymer 451, Polymer 452, Polymer 453, E FKA-1 501, EFKA-1 502, EFKA-4540, EFKA-4550 (all manufactured by EFKA Chemical), Floren TG-720 Floren_730W, Floren 740W, Floren 1

745W, (Kyoeisha Chemical Co., Ltd.), Azispar PW911, Azispar PB

821 (above, manufactured by Ajinomoto Co.), Joncryl 678, Joncryl 679, Joncryl 62 (all, manufactured by Johnson Polymer). These may be used alone or in combination of two or more.

 The content of the high molecular weight pigment dispersant is preferably 30 to 1000 parts by weight based on 100 parts by weight of the noble metal or copper. When the amount is less than 30 parts by weight, the dispersibility of the noble metal or copper colloid particles is insufficient. When the amount exceeds 1000 parts by weight, the alcohol solution of the noble metal or copper colloid is used for the sol-gel method. In such a case, the physical properties of the obtained thin film may be poor. More preferably, it is 40 to 650 parts by weight. The alcohol solution of a colloid of a noble metal or copper of the present invention is an organosol using the above-mentioned alcohol having 1 to 4 carbon atoms as a solvent, and the concentration of the noble metal or copper can be 1 Ommo 1/1 or more. If it is less than 1 Ommo 1/1, it is not possible to obtain a high-concentration alcohol solution of colloid. More preferably, it is 50 mmolZl or more.

 In the alcohol solution of the noble metal or copper colloid of the present invention, the average particle size of the colloid particles is preferably 5 to 50 nm. If it is less than 5 nm, the coloring power is weak, and if it exceeds 50 nm, the saturation becomes low.

In the alcoholic solution of the noble metal or copper colloid of the present invention, the solid content of the colloid particles and the polymer dispersant can be arbitrarily set, for example, 1 to 50% by weight. Further, the metal concentration in the solid content is preferably about 10% by weight or more. If it is less than this, the desired effect cannot be obtained because the metal content is too low. The upper limit is not particularly specified, but can be, for example, 98% by weight or less. You.

 The alcohol solution of a noble metal or copper colloid of the present invention is obtained by dissolving the above noble metal or copper compound in an alcohol having 1 to 4 carbon atoms and reducing the compound to noble metal or copper in the presence of a high molecular weight pigment dispersant. Obtainable.

 The method for the reduction is not particularly limited, and examples thereof include a method of chemically reducing the compound by adding a reducing compound, a method of irradiating light with a high-pressure mercury lamp, and the like. The addition of the compound in the chemical reduction method may be performed after the addition of the polymer pigment dispersant. Alternatively, the polymer pigment dispersant and the compound may be mixed first, and the mixture may be used. In the form of addition to a solution of a noble metal or copper compound. The reducing compound is preferably an alcohol-soluble compound, for example, an alkali metal borohydride salt such as sodium borohydride which has been conventionally used as a reducing agent; a hydrazine compound; a hydroxylamine compound; Acid salt; a sulfoxylate derivative; formaldehyde; an organic acid having 1 to 6 carbon atoms such as formic acid or a salt thereof, citric acid or a salt thereof, succinic acid or a salt thereof, tartaric acid or a salt thereof, L-ascorbic acid or a salt thereof, or Its salts and the like can be used. In the present invention, an amine can be used in addition to the conventional reducing agent. One or more of these can be used.

 The above-mentioned amine is not usually used as a reducing agent. However, by adding the amine to the above-mentioned solution of the noble metal or copper compound, stirring and mixing, the noble metal ion or copper ion becomes noble metal at around room temperature. It is reduced to copper. By using the above-mentioned amine, it is not necessary to use a dangerous reducing agent or a highly harmful reducing agent, and without heating or using a special light irradiation device, about 5 to 100 ° C, preferably The noble metal or copper compound can be reduced at a reaction temperature of about 20 to 80 ° C.

The above-mentioned amine is not particularly limited, and for example, those exemplified in JP-A-11-8647 can be used. Propamine, butyramine, hexylamine, getylamine, dipropylamine, getylmethy Noreamine, triethynoleamine, ethylenediamine, N, N, Ν ', N'-aliphatic amines such as tetramethinoleethylenediamine, triethylenetetramine; piperidine, dimethylamine Alicyclic amines such as tilpiperidine, piperazine, pyrrolidine, morpholine and derivatives thereof; aromatic amines such as aniline, 1, luidine, anisidine, phenetidine and derivatives thereof; benzylamine, phenethylamine, xylylenediamine; And aralkylamines such as derivatives thereof. Examples of the above amine include methylaminoethanol, dimethylaminoethanol, methylaminoethanol, triethanolamine, ethanolamine, diethanolamine, methylethanolanolamine, propanolanolamine, 2- (3-aminopropylamino) Alkanolamines such as ethanol, butanolamine, hexanolamine and dimethylaminopropanol can also be mentioned. Of these, alkanolamine is preferred, and 2-dimethylaminoethanol is more preferred.

 The amount of the amine to be added is preferably 1 to 50 mol per 1 mol of the noble metal or copper compound. If it is less than lmo1, the reduction is not performed sufficiently, and if it exceeds 50mo1, the stability of the generated colloidal particles with respect to aggregation decreases. More preferably, it is 2 to 8 mol.

When sodium borohydride is used as the reducing agent, the sodium borohydride is expensive and must be handled with care. There is no need to prepare a light irradiation device. The amount of the sodium borohydride to be added is preferably 1 to 5 Omo 1, more preferably 1.5 to L Omol, per 1 mo 1 of the noble metal or copper compound. When citric acid or a salt thereof is used as the reducing agent, noble metal ions, copper ions, and the like can be reduced by heating and refluxing in the presence of an alcohol. The above citric acid or its salt has the advantage that it is very inexpensive and easily available. As the citric acid or a salt thereof, sodium citrate is preferable. In the case of using sodium catenate, the reduction action is improved when iron (II) sulfate is used in combination, so that the reduction reaction can proceed under milder conditions. However, when sodium citrate and iron (II) sulfate are mixed, insoluble iron (II) citrate is formed when the stoichiometry of citrate and iron (II) ions is adjusted, and when sedimentation occurs, Trouble occurs. For this purpose, it is necessary to add iron (II) sulfate so that the amount of sodium citrate becomes excessive. In addition to iron (II) sulfate, the reducing action can be improved by using it together with, for example, a sulfoxylate derivative in addition to citric acid.

 Further, salts of humic acid, tartaric acid and the like with the above-mentioned amines are also preferable because both the acid and the ammine have a reducing property.

 The addition amount of the above citric acid or a salt thereof is preferably 1 to 50 mol per 1 mol of the noble metal or copper compound. If it is less than 1 m o 1, the reduction is not sufficiently performed, and if it exceeds 5 m o 1, the stability against aggregation decreases. More preferably, it is 1.5 to 1 Omo1.

 The method for producing a noble metal or copper colloid alcohol solution of the present invention comprises dissolving the noble metal or copper compound in a solvent containing an alcohol having 1 to 4 carbon atoms to form a solution, and adding a high molecular weight pigment dispersant. When reduced to noble metal or copper, it can be carried out simply and with few steps, and has high color saturation, and a colloidal solution of noble metal or copper with a concentration of 10 times or more higher than that of the conventional colloidal solution of noble metal. Can be manufactured. Particularly, by using alkanolamine, it can be easily produced under mild conditions of about 20 to 80 ° C. The high molecular weight pigment dispersant used in the method for producing a colloidal solution of a noble metal or copper colloid according to the present invention is the same as that described for the alcohol solution of a noble metal or copper colloid described above.

 The solution after the reduction is, in addition to the metal colloid particles and the polymer pigment dispersant, miscellaneous ions such as chloride ions derived from the raw material of the noble metal or copper colloid solution, salts generated by reduction, and in some cases, It contains amines, and these miscellaneous ions and chlorides may adversely affect the stability of the resulting colloidal solution of noble metal or copper, so it is desirable to remove them. For the removal of these components, electrodialysis, centrifugation, and ultrafiltration are used. However, as described later, centrifugation and ultrafiltration are preferably used because concentration is performed.

The method of preparing a colloidal solution of a noble metal or copper colloid according to the present invention involves concentrating an alcohol solution of a colloidal noble metal or copper obtained earlier, and then adding the above-mentioned alcohol to the concentrated solution. It is characterized by adding and diluting a solvent different from coal. As the above-mentioned concentration method, centrifugal separation and ultrafiltration are preferable, since various methods can simultaneously remove foreign ions and saltamine. For dilution after concentration, a solvent different from the above alcohol is used, and by repeating this concentration and dilution, the solvent can be substantially replaced. As the above different solvent, water is preferable from the viewpoint of workability and ease of handling. The aqueous solution of the noble metal or copper colloid obtained in this way has a sharper absorption curve than that produced using water as a solvent.

 The alcohol solution of the precious metal or copper colloid of the present invention and the precious metal or copper colloid solution obtained by the above solution preparation method can be suitably used for the sol-gel method.

 In the sol-gel method, generally, an alcohol, water necessary for hydrolysis, and an acid or base as a catalyst are added to a metal alkoxide, and the mixture is stirred at room temperature to 80 ° C. to undergo hydrolysis and condensation polymerization. It is. By these reactions, a sol in which metal oxide particles are dispersed in a colloidal state is easily obtained. When the sol is transformed into a gel to form a film, the sol solution can be used as a coating composition. Using the above sol solution, a sol film can be formed on a substrate by a dipping method, a spin coating method, or the like. The coated sol film is dried at room temperature and then heated at an appropriate temperature to obtain a gel thin film or a glass thin film which is an inorganic coating.

 The coating composition of the present invention comprises the above alcohol solution of a noble metal or copper colloid and a metal alkoxide. Another coating composition of the present invention comprises the above-mentioned colloidal solution of a noble metal or copper and a metal alkoxide.

As the metal alkoxide, those usually used in the sol-gel method can be used. For example, M (OR) _n (M is a metal atom, R is an alkyl group, and n is an acid number of a metal. ) Can be mentioned.

As the above metal alkoxide, Si (OR) ₄ is generally used. As the genus atoms M, those of Zn, Zr, Ti, Al, Fe, Co, and Ni can be used according to the purpose. Examples of the alkoxy group in the metal alkoxide include an alkoxy group having 1 to 5 carbon atoms such as methoxy, ethoxy, propoxy, butoxy, pentyloxy and the like. Among these, an ethoxy group is more preferable in that it has good reactivity.

 As the above-mentioned metal alkoxide, tetraethoxysilane is particularly preferable in terms of easy handling.

 Examples of the solvent for the metal alkoxide solution include those composed of alcohol and water. The number of moles of alcohol per mole of water can be selected depending on the properties of the target thin film, but is usually preferably 1 to 30. If the number of moles of alcohol per mole of water is less than 1, hydrolysis of the metal alkoxide progresses too much and lacks stability.If it exceeds 25, hydrolysis of the metal alkoxide becomes insufficient and is not practical. Not a target. The mole number of the alcohol per 1 mole of the water is more preferably from 10 to 25.

 The alcohol in the metal alkoxide solution is not particularly limited, and for example, those exemplified as the alcohols contained in the alcohol solution of the noble metal or copper colloid of the present invention and alcohols having 5 carbon atoms can be used.

 The metal alkoxide solution may contain an acid or a base as a catalyst, but preferably contains an acid when forming an inorganic coating. The acid is not particularly limited, and examples thereof include hydrochloric acid and nitric acid.

 The metal alkoxide solution may further contain, if necessary, additives such as a drying inhibitor, a colored transition metal compound other than the noble metal or copper, a silane coupling agent, and an organic dye. The drying inhibitor is not particularly limited, and examples thereof include dimethylformamide and dimethylacetamide.

The coating composition of the present invention is obtained by adding a noble metal or copper colloidal alcohol solution or a noble metal or copper colloidal solution to the metal alkoxide solution and stirring the mixture. As the ratio of the above-mentioned addition, the above-mentioned noble metal or copper colloidal alcohol solution or the noble metal or copper It is preferable to add the colloidal particles of the noble metal or copper so that the concentration of the colloidal particles of the noble metal or copper in the state where the colloidal solution is added is 0.01 to 70% by weight. In the case where addition to an organic solvent is used as a dispersion medium or when water is used as a dispersion medium and there is a problem in stability, it is preferable to use a colloidal alcohol solution of a noble metal or copper. If the amount is less than 0.01% by weight, the effect of the addition cannot be sufficiently obtained. If the amount exceeds 70% by weight, the stability of the coating composition may be poor. As will be described later, when it is desired to obtain a metallic luster on the inorganic coating obtained using the coating composition of the present invention, the concentration of the noble metal or copper colloid particles is higher than in the case where it is not so. Tend. The substrate on which the coating composition used in the above sol-gel method is applied is not particularly limited, and examples thereof include metals such as aluminum and stainless steel, glass, and plastics. And / or both surfaces may be subjected to surface processing.

 As the coating method, in addition to the above-described methods such as the dip method and the spin coating method, when the substrate is a metal such as aluminum, electrophoresis can be used. By baking the film thus obtained, an inorganic coating can be obtained. The calcination can be preferably performed at 100 to 500 ° C. The calcination can be preferably performed for 5 to 120 minutes.

 The inorganic coating obtained by forming a film by the sol-gel method using the alcoholic solution of the noble metal or copper colloid of the present invention or the coating composition containing the noble metal or copper colloid solution contains metal. Higher concentrations can have a metallic luster. The metallic luster mentioned here includes a state called a half mirror. Those having this metallic luster can be used not only as an electromagnetic wave shield but also as a design material. On the other hand, inorganic coatings with a high color depth and high saturation can be used as optical materials, for example, optical materials such as heat-resistant optical filters and non-linear optical materials, and coloring materials with high heat resistance and high durability. In addition, it can be used for antibacterial materials and catalysts.

The thickness of the inorganic coating can be selected according to the application to be used, but when it is used as an optical material, the dry thickness is preferably 0.05 to 10 / xm. When the film thickness is less than 0.05 / im, coloring power or electromagnetic wave shielding power may be lacked. When the film thickness exceeds Ομππ, peeling or cracking due to heating tends to occur. The thickness is preferably 0.1 to 5 μΐη.

 Since the inorganic coating as an optical material produced by the above method uses the above-mentioned alcohol solution of a noble metal or copper colloid or a solution of a noble metal or copper colloid as a coloring agent, the resulting thin film is vivid. Color is applied and the applied color is chemically stable and does not fade. The optical material is not particularly limited, and examples thereof include an optical filter such as a colored coating on the surface of a CRT of a television.

 The alcohol solution of the noble metal or copper colloid of the present invention or the solution of the noble metal or copper colloid can be added to the metal alkoxide solution used in the sol-gel method, and a stable coating composition can be obtained. Obtainable. In addition, the noble metal or copper colloidal alcohol solution or the noble metal or copper colloidal solution of the present invention has a sharper absorption curve than conventional ones. Higher saturation can be realized.

 In the present invention, the reason why the absorption curve becomes sharper than the conventional one is not clear, but the following may be considered.

 In the conventional aqueous colloidal solution of a noble metal or copper described in Japanese Patent Application Laid-Open No. 11-080647, etc., an interaction acts between the molecules of the high-molecular-weight pigment dispersant. Entangling and coordinating with the individual colloidal particles to be dispersed and the function as a protective colloid is not very high.As a result, the colloidal particles are uniformly and finely dispersed to narrow the particle size distribution. Seems to have limitations.

However, in the alcohol solution of the noble metal or copper colloid or the noble metal or copper colloid solution of the present invention, alcohol is used in the production process, so that the molecular weight of the high molecular weight pigment dispersant The effect is small, the degree of freedom of each dispersant molecule is high, the kinetic rate is low, and it is easy to coordinate with each of the noble metal or copper particles to be dispersed, and the particle size of each colloid particle Acts as a protective colloid in a small state, the particle size distribution becomes narrow, and as a result, the absorption curve It is thought that it becomes a loop. In addition, when the alcohol solution of the noble metal or copper colloid of the present invention is produced, the reaction temperature can be increased as compared with the prior art, but this can also narrow the particle size distribution. It is considered to be one factor. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an absorbance curve showing the particle size distribution of gold colloid particles in an alcohol solution of gold colloid. The solid line is for the toluene solution of gold colloid obtained in Production Example, and the broken line is for the ethanol solution of gold colloid obtained in Example 1. The horizontal axis represents wavelength (nm), and the vertical axis represents absorbance. BEST MODE FOR CARRYING OUT THE INVENTION

 Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to only these Examples.

 Reference example Selection of high molecular weight pigment dispersant

 As high molecular weight pigment dispersants, there are Dispervik 190, Dispervik 191, Dispervik 192 and Dispervik 184 (all manufactured by Big Chemie), EF KA—450 and EF Place 0.5 g of KA-4450 (all manufactured by EF KA Chemikanole), Solsperse 2400 and Solsperse 2800 (all manufactured by Abyssia) in a container, and place in each container. 1 Om1 of acetone was added and stirred to dissolve the polymer pigment dispersant. One to several drops of water were added dropwise to the mixture with a burette while stirring, and the amount of drop A at the time of clouding was recorded. Separately from this, hexane was used in place of the water, and the amount of hexane dropped B at the time of cloudiness was determined. The study was first performed with respect to equation (1), and when the evaluation was X based on the following criteria, equation (2) was examined. Equation (1) was evaluated as follows. ◎: When the expression (1 ′) is satisfied.

 〇: When expression (1 ′) is not satisfied, but expression (1) is satisfied.

 X: when formula (1) is not satisfied.

Equation (2) was evaluated as follows. 〇: When equation (2) is satisfied.

 X: when the formula (2) is not satisfied.

In addition, the amount of dripping in the case of no cloudiness was calculated at 5 Om1. The results are shown in Table _1c

From the results in Table 1, it can be said that Dispervik 190, Dispervik 191, Disparvik 192, EFKA-4550, EFKA-4540 are suitable. Of these, the Desperbic 190 and the Despervik 191 were preferred.

 Example 1 Preparation of colloidal gold solution in ethanol

Taken tetrachloroethene mouthpiece (III) acid tetrahydrate _{(HAu C 14 ■ 4H 2 0} ) 1 2 g to a reaction vessel containing ethanol 230 g, and dissolved by stirring. Further, 9 g of Dispervic 191, manufactured by Vic Chem Inc., was added as a polymer pigment dispersant, and the mixture was stirred. After the polymer pigment dispersant was dissolved, the mixture was heated using a water bath until the liquid temperature reached 50 ° C. With stirring, 13 g of 2-dimethylaminoethanol was added instantaneously. After the addition, the mixture was stirred for 2 hours while maintaining the liquid temperature at 50 ° C, to obtain a vivid and thick red colloidal ethanol solution of gold colloid. The ethanol solution of the obtained colloidal gold is removed by filtration using an ultrafiltration pencil-type module AHP-0113 manufactured by Asahi Kasei Corporation, and ethanol is added to the obtained filtrate, followed by further filtration. By repeating the above steps, 37 g of a colloidal gold ethanol solution having a solid content of 20% by weight / o and comprising gold colloid particles and a polymer pigment dispersant, from which residual ion components were removed, were obtained. As a result of TG-DTA (manufactured by Seiko Instrument), the content of gold particles in the solid content was 70% by weight. /. Met. Example 2 Preparation of gold colloid in ethanol

As a polymeric pigment dispersant, 20 g of EF KA-450 550, 14 g of dimethylaminoethanol and 200 g of ethanol manufactured by EF KA Chemical Co., Ltd. were placed in a reaction vessel, and stirred. The polymer pigment dispersant was completely dissolved. On the other hand, tetrachloroethene mouthpiece (III) acid tetrahydrate (HA u C 1 4 ■ 4 H 2 0) was dissolved 1 2 g of ethanol 1 0 0 ml. While stirring the ethanol solution of the polymer pigment dispersant, an ethanol solution of tetraclo mouth (III) acid tetrahydrate was added thereto instantaneously. Stirring was continued for 1 hour at room temperature to obtain a vivid, thick red ethanol solution of colloidal gold. The ethanol solution of the obtained colloidal gold was removed by filtration using an ultrafiltration pencil type module AHP-001, manufactured by Asahi Kasei Corporation, and ethanol was added to the obtained filtrate, followed by further filtration. This step was repeated to obtain 37 g of a 22% by weight solid solution of a gold colloidal ethanol solution containing colloidal gold particles and a polymeric pigment dispersant, from which residual ion components had been removed.

 From the results of the measurement, it was confirmed that the gold content in the solid content was 65% by weight.

 Example 3 Ethanol solution of gold colloid

 According to Example 2, except that 20 g of EF KA-450 manufactured by EF KA Chemical was used instead of EF KA-450 manufactured by EF KA Chemical as a polymer pigment dispersant, the gold colloid was used. 37 g of a solution of gold colloid in ethanol having a solid content of 22% by weight and consisting of particles and a polymer pigment dispersant and exhibiting a bright and dense red color was obtained. As a result of T G—D T A measurement, the content of gold particles in the solid content was 65% by weight. /. Met.

 Example 4 Methanol solution of silver colloid

Take 11 g of silver perchlorate into a reaction vessel, take 192.10 g of Dispervic (manufactured by Big Chemical Co., Ltd.) and 300 g of methanol as polymer pigment dispersants, and dissolve the resin component until it dissolves. Stirred. The aqueous solution in which the resin component was dissolved was added to the above-mentioned aqueous solution of silver perchlorate, and heated using a water bath so that the temperature of the solution became 50 ° C. Here, 24 g of 2-dimethylaminoethanol was added instantaneously with stirring. After addition of 2-dimethylaminoethanol, the mixture was further stirred at 50 ° C for 6 hours, and then It was left still at ° C. Next, using an ultrafiltration pencil-type module AHP-001 made by Asahi Kasei Corporation, a process of removing residual ions by filtration, adding methanol to the obtained filtrate, and performing further filtration, was repeated. 20 g of a viscous and thick yellow colloidal methanol solution having a solid content of 40% by weight and comprising silver colloid particles and a polymer pigment dispersant, from which residual ion components had been removed, were obtained. As a result of TG-DTA measurement, the content of silver particles in the solid was 53% by weight.

 Example 5 Ethanol solution of silver colloid

 Take 11 g of silver perchlorate into a reaction vessel, take 20 g of Dispervic 190 manufactured by BYK-Chemie as a polymeric pigment dispersant and 300 g of ethanol, and dissolve the resin component And stirred. The aqueous solution in which the resin component was dissolved was added to the above-mentioned aqueous solution of silver perchlorate, and heated using a water path so that the temperature of the solution became 50 ° C. Here, 24 g of 2-dimethylaminoethanol was added instantaneously while stirring. After the addition of 2-dimethylaminoethanol, the mixture was further stirred at 50 ° C for 6 hours, and then left at 50 ° C for a while. Next, a process of removing residual ions by filtration using Asahi Kasei's ultrafiltration vencil type module AHP-0113, and adding ethanol to the obtained filtrate to carry out further filtration. This process was repeated to obtain 20 g of a vivid, thick yellow ethanol solution of silver colloid having a solid content of 40% by weight and comprising silver colloid particles and a polymer pigment dispersant, from which residual ion components had been removed. As a result of TG-DTA measurement, the content of silver particles in the solid was 55% by weight.

 Example 6 Preparation of Ethanol Solution of Palladium Colloid

14.5 g of palladium (II) chloride dihydrate was placed in a container together with 300 g of ethanol, and stirred to dissolve. Further, 22 g of Dispervic 190 manufactured by BYK Chemie was added as a polymer pigment dispersant, and the mixture was stirred until the polymer pigment dispersant was dissolved. 36 g of citric acid, 23 g of 2-dimethylaminoethanol and 100 g of ethanol were placed in another container, and stirred until the citric acid was dissolved. This ethanol solution was instantaneously added to the palladium chloride solution with stirring, and the mixture was stirred at room temperature for 2 hours to obtain a palladium colloid aqueous solution. The ethanol solution of the palladium colloid thus obtained was used with an ultrafiltration pencil type module AHP-0113 manufactured by Asahi Kasei Corporation. Then, a process of removing residual ions by filtration, adding ethanol to the obtained filtrate, and further filtering the mixture was repeated, and the palladium colloid particles and the polymer pigment dispersant from which the residual ion components were removed were removed. 30 g of a thick brown palladium colloid ethanol solution having a solid content of 40% by weight was obtained. As a result of TG-DTA measurement, the content of palladium particles in the solid content was 58 wt. /. Met.

 Comparative Example 1 Ethanol solution of colloidal gold

However _c was tried the preparation of ethanol solution of gold colloid according to Example 1 in addition to using Bikkukemi one company made of Disperbyk 1 8 4 1 8 g as a high-molecular weight pigment dispersant, gold particles and disperser big 1 8 4 A massive precipitate consisting of the following was formed, and an ethanol solution of gold colloid was not obtained.

 Comparative Example 2 Ethanol solution of silver colloid

 Preparation of a silver colloid ethanol solution was attempted according to Example 5 except that 240 g of Solsperse manufactured by Avicia was used as a high molecular weight pigment dispersant. A massive precipitate consisting of silver particles and Solsperse 2400 was formed, and a silver colloid ethanol solution was not obtained.

 Comparative Example 3 Ethanol solution of silver colloid

 An ethanol solution of silver colloid was prepared in accordance with Example 5 except that 280.10 g of Solsperse manufactured by Avicia was used as a high molecular weight pigment dispersant. However, a massive precipitate composed of silver particles and Solsperse 2800 was formed, and a silver colloid ethanol solution was not obtained.

 Production example Preparation of toluene solution of colloidal gold

Tetrachloroethene mouthpiece (III) acid tetrahydrate (HA u C 1 4 ■ 4 H 2 0) 1 2 g, together with the water 4 0 g taken in a reaction vessel and stirred to dissolve. On the other hand, 4 g of Solsperse 280.000 and Aceton (60 g) manufactured by Avicia Co., Ltd. were placed in another container as a polymer pigment dispersant, and the polymer pigment dispersant was dissolved by stirring. This polymer pigment dispersant solution was added to a reaction vessel containing an aqueous solution of tetrachlorobase (III) acid, and 13.0 g of 2-dimethylaminoethanol was added instantaneously with stirring. Then, after further stirring at room temperature for 1 hour, acetone was dried and removed. With the decrease in the amount of acetone, Gold colloid protected by the polymeric pigment dispersant precipitated and precipitated. The supernatant aqueous layer was removed by decantation, and the gold mouth was further washed with distilled water and completely dried to obtain 8 g of a gold non-polar solvent-soluble solid sol. As a result of TG-DTA measurement, the content of gold particles in the solid content was 70% by weight.

 8 g of the obtained solid sol of gold was placed in a container, and 12 g of toluene was added thereto, followed by stirring to dissolve the solid sol of gold. As a result, a thick red colloidal toluene solution of gold colloid was obtained.

 Example 7 Measurement of absorbance

 The ethanol solution of gold colloid obtained in Example 1 was further greatly diluted with ethanol and transferred to a glass cell having a bottom surface of 1 cm X lcm, and a spectrophotometer MCPD—300 manufactured by Otsuka Electronics Co., Ltd. was used. When the absorbance was measured in the range of 380 nm to 780 nm according to 0, the absorption derived from the plasmon of the colloidal gold having a maximum at the wavelength of 530 nm could be observed. FIG. 1 shows an absorption curve in which the concentration of colloidal gold was adjusted so that the absorbance at the maximum of the absorption peak was 1.5.

 Comparative Example 4 Measurement of Absorbance

 The toluene solution of colloidal gold obtained in Production Example was further greatly diluted with toluene, and the absorbance was measured in the same manner as in Example 7.The absorption derived from the plasmon of the gold colloid having a maximum around 535 nm was found. I could observe it. FIG. 1 shows an absorption curve in which the concentration of the gold colloid was adjusted so that the absorbance at the maximum of the absorption peak was 1.5.

 Example 8 Preparation of composition for coating used in sol-gel method

Tetraethoxysilane 7.0 wt% nitric acid 1.3 wt% water 1.5 wt%, I isopropanol 8 9. 7 mixture by weight _^0/0, to obtain a tetraethoxysilane solution was stirred. 0.5% by weight of the ethanol solution of gold colloid obtained in Example 1 was added to the above tetraethoxysilane solution, followed by stirring to prepare a coating composition. This coating composition was stable for 24 hours at room temperature.

Examples 9 to 12 Preparation of Coating Composition Used for Sol-Gel Method In Example 8, the alcohol solution of Examples 2 to 5 was used instead of the ethanol solution of colloidal gold obtained in Example 1 respectively. Except for the same procedure, Each of the compositions for inging was prepared. All of these coating compositions were stable at room temperature for 24 hours.

 Comparative Example 5 Preparation of coating composition used for sol-gel method

 In Example 8, a coating composition was prepared in the same procedure except that the toluene solution of colloidal gold obtained in Production Example was used instead of the ethanol solution of colloidal gold obtained in Example 1. However, they did not mix well, and a coating composition could not be obtained.

 Example 13 Preparation of Colored Glass Gel Film by Sol-Gel Method

 The coating composition obtained in Example 8 was applied to a glass plate by spin coating, and then baked at 150 ° C. for 20 minutes to obtain a colored glass gel film having a thickness of 0.2 μιη. Was formed on a glass substrate.

 The colored glass gel film was transparent and colored red. A rubbing test with a detergent was performed to evaluate the water resistance of the colored glass gel film, but no decolorization was observed. When the pencil hardness of the colored glass gel film was measured in accordance with JISK 540, it was 8 mm, and a sufficient hardness was obtained.

 Example 14 Preparation of Colored Glass Gel Film by Sol-Gel Method

 The coating composition obtained in Example 11 was applied to a glass plate by a spin coating method, and then baked at 150 ° C. for 20 minutes to form a coating having a thickness of 0.2 μm. A colored glass gel film was formed on a glass substrate.

 This colored glass gel film was transparent and colored yellow. A rubbing test with a detergent was performed to evaluate the water resistance of the colored glass gel film, but no decolorization was observed. When the pencil hardness of the colored glass gel film was measured in accordance with JISK 540, it was 8 mm, and a sufficient hardness was obtained.

 Example 15 Preparation of aqueous solution of 5 colloidal gold

The ethanol solution of the gold colloid obtained before the ultrafiltration obtained in Example 1 was subjected to the residual ion separation using an ultrafiltration pencil type module manufactured by Asahi Kasei Corporation. Was removed by filtration, and a step of adding water to the obtained filtrate and further performing filtration was repeated. By repeating this operation, the residual ion component is removed. In both cases, the solvent was replaced with water from ethanol to obtain 37 g of an aqueous solution of colloidal gold composed of colloidal gold particles and a polymer pigment dispersant with a solid content of 25% by weight. As a result of TG-DTA measurement, the content of gold particles in the solid content was 56% by weight.

 When the absorbance was measured by a spectrophotometer in the same manner as in Example 7, an absorption curve having a sharpness equivalent to that of the ethanol solution of colloidal gold obtained in Example 1 was obtained.

 When a predetermined high molecular weight pigment dispersant was used in Examples 1 to 6, an alcoholic solution of metal colloid was obtained. From the results of Examples 8 to 12, these alcohol solutions of metal colloids could be mixed without any problem even when added to the coating composition used in the sol-gel method, and showed a stable state. Further, from the results of Examples 13 and 14, it was possible to obtain a coating gel film having excellent coloring properties and excellent water resistance and coating film hardness.

 On the other hand, in Comparative Examples 1 to 3, when a high-molecular-weight pigment dispersant other than the above-described predetermined high-molecular-weight pigment dispersant was used, an alcohol solution of a metal colloid was not obtained. From the results of Comparative Example 5, the toluene solution of gold colloid prepared in the Production Example was not suitable for use in the coating composition used in the sol-gel method. From the results of FIG. 1 in Example 7 and Comparative Example 4, the absorption curve derived from the ethanol solution of the colloidal gold of Example 1 was sharper than the absorption curve derived from the toluene solution of the colloidal gold of Production Example, In particular, sharp particles were obtained on the long wavelength side, indicating that the particle size distribution of the colloidal gold particles was narrow.

 In addition, it was confirmed that the characteristics of the particle size distribution were maintained even when the solvent was replaced with water in Example 15 in Example 15. Industrial applicability

The colloidal alcohol solution of a noble metal or copper of the present invention, and the colloidal solution of a noble metal or copper obtained by the solution preparation method of the present invention have the above-described configuration, and contain a high concentration of noble metal or copper colloid particles. And the absorption curve becomes sharper than before, so that it also has excellent coloring properties. it can. Furthermore, since it can be suitably used for the sol-gel method, the inorganic coating obtained by the sol-gel method can be used for optical materials such as optical filters and non-linear optical materials having excellent heat resistance, coloring materials, antibacterial materials, catalysts, and electromagnetic wave shielding. It can be suitably used for example.

Claims

The scope of the claims

1. An alcoholic solution of a noble metal or copper colloid comprising a noble metal or copper colloid particle and a high molecular weight pigment dispersant, wherein the alcohol has 1 to 4 carbon atoms, and the high molecular weight pigment dispersant is An alcohol solution of a noble metal or copper colloid, which satisfies the following formula (1) or (2).

 (1) A≥3m1 and 3m1≤B≤4 Om1

 (2) 0.25≤A / B≤4.5

 [Wherein A and B each represent a solution of 0.5 g of the high molecular weight pigment dispersant in an acetone solution containing 10 g of acetone dissolved in water or hexane, until the acetone solution becomes cloudy. Of the water (ml) and the amount of the hexane added (ml) until the acetate solution becomes cloudy. ]

2. The alcohol solution of a noble metal or copper colloid according to claim 1, wherein the alcohol is a monoalcohol having 2 to 4 carbon atoms.

3. The alcohol solution of a colloid of a noble metal or copper according to claim 1 or 2, wherein the formula (1) is the following formula (1 ').

 (1 ') A≥ 1 Om 1 and 4 m 1≤B≤ 2 Om 1

4. A method for producing an alcohol solution of a colloid of a noble metal or copper, in which a compound of a noble metal or copper is dissolved in an alcohol having 1 to 4 carbon atoms and reduced to a noble metal or copper in the presence of a high molecular weight pigment dispersant. A method for producing a colloidal alcohol solution of a noble metal or copper, wherein the high molecular weight pigment dispersant satisfies the following formula (1) or (2).

 (1) A 3m 1 and 3m 1≤B≤4 Om 1

 (2) 0.25≤A / B≤4.5

 Wherein A and B are the high-molecular weight pigment dispersants 0.

5 g Acetone 10 the amount of water added (ml) until the acetone solution becomes turbid when water or hexane is added to the acetone solution dissolved in m1, and the hexane until the acetone solution becomes turbid. (Ml). 5. An alcohol solution of a noble metal or copper colloid obtained by the production method according to claim 4.

6. After concentrating an alcohol solution of a noble metal or copper colloid obtained by the production method according to claim 4, diluting the concentrated solution by adding a solvent different from the alcohol. A method for preparing a colloidal solution of a noble metal or copper, which is characterized by the following.

7. The method for preparing a solution of a colloid of a noble metal or copper according to claim 6, wherein the different solvent is water.

8. A solution of a noble metal or copper colloid obtained by the solution preparation method according to claim 6 or 7.

9. A coating composition comprising a noble metal or copper colloid alcohol solution according to claim 1, 2, 3, or 5, and a metal alkoxide.

10. A coating composition comprising the colloidal solution of a noble metal or copper according to claim 8 and a metal alkoxide.

11. An inorganic coating obtained by using the coating composition according to claim 9 or 10.

12. A method for forming an inorganic film, comprising forming an inorganic film on a substrate using the coating composition according to claim 9 or 10.