JP5116218B2 - Dispersion and method for producing dispersion - Google Patents

Description

  The present invention relates to a technique for manufacturing a reflector used in an LDC or the like.

  As a reflective film used for a reflector for a reflective LCD (Liquid Crystal Display), a high reflectance is required. Therefore, conventionally, a pure Al film, an Al alloy-based film containing Al as a main component, or pure Ag is used. A film, an Ag alloy film mainly composed of Ag, or the like is used.

  Of these, the Al film is prone to corrosion due to salt, moisture, etc. and has a problem that the reflectance decreases with time. Therefore, the use of an Ag film having better reflection characteristics than the Al film has been proposed ( For example, see Patent Document 1.)

  In this case, as a method for forming the Ag film, vacuum deposition or sputtering is used, and lithography is used for the patterning. The Ag film has better reflection characteristics in the visible light range than the Al film, but has a problem in heat resistance.

  During the LCD manufacturing process, a heat treatment process of about 250 ° C. is usually performed several times, the total heat treatment time is about 1 hour, and the heat load generated during the operation of the LCD even after the LCD is manufactured. Therefore, there is a problem that the reflection characteristic of the Ag film is deteriorated.

  In addition, the Ag film has a problem in weather resistance, which causes deterioration of reflection characteristics and adhesion under high humidity. Furthermore, in the prior art, a film forming process by vacuum deposition or sputtering and a patterning process by lithography are used, so that the process is complicated, the equipment is large, and the cost is naturally high.

Japanese Patent Laid-Open No. 2004-231982 JP 2001-35255 A JP 2005-54268 A

  The present invention has been made to solve the above problems, and an object of the present invention is to obtain a reflective film having excellent reflection characteristics and high heat resistance.

In order to solve the above-mentioned problems, the invention according to claim 1 is for forming a reflective film in which metal particles mainly composed of silver are dispersed in a dispersion solvent and coated on an inorganic oxide and heated to form a reflective film. A nonpolar solvent and an organic tin compound, and tin was contained in an amount of 0.1 wt% to 5 wt% based on the total weight of silver and tin contained in the dispersion. It is a dispersion.
A second aspect of the present invention is the dispersion liquid according to the first aspect, wherein the metal particles have a particle size of 100 nm or less.
Invention of Claim 3 is a dispersion liquid of any one of Claim 1 or Claim 2, Comprising: As said nonpolar solvent, either the xylene and the tetradecane, or the dispersion liquid in which both were contained. is there.
Invention of Claim 4 is a manufacturing method of the dispersion liquid which produces the dispersion liquid of Claim 1, Comprising: The metal material which has silver as a main component is evaporated in the vapor | steam atmosphere containing an inert gas. Producing metal particles, contacting the surface of the metal particles with a vapor of a first solvent, forming a film of the first solvent on the surface of the metal particles, the first solvent as a second solvent Substituting and producing a treatment liquid having the metal particles and the second solvent, and then replacing the second solvent with a third solvent containing a nonpolar solvent, containing silver and tin In the method for producing a dispersion, an organotin compound is added so as to contain tin in a range of 0.1 wt% to 5 wt% with respect to the total weight, and a dispersion in which the metal particles are dispersed is created. is there.
The invention according to claim 5 is the method for producing a dispersion according to claim 4, wherein the metal material contains tin.
Invention of Claim 6 is a manufacturing method of the dispersion liquid of any one of Claim 4 or Claim 5, Comprising: Any one of C5 or more alcohol or organic ester is said 1st solvent. Or it is the manufacturing method of the dispersion liquid which uses both.
The invention according to claim 7 is the method for producing a dispersion according to claim 6, wherein α-terpineol is used for the alcohol having 5 or more carbon atoms.
The invention according to claim 8 is the method for producing a dispersion according to any one of claims 4 to 7, wherein the dispersion is produced by using a polar solvent as the second solvent.
The invention according to claim 9 is the method for producing a dispersion according to claim 8, wherein the polar solvent is acetone.
Invention of Claim 10 is a manufacturing method of the dispersion liquid of any one of Claim 4 thru | or 9, Comprising: Xylene and the dispersion which uses any one or both of tetradecane as said nonpolar solvent It is a manufacturing method of a liquid.

  The present invention is configured as described above. When the dispersion liquid of the present invention is applied to a substrate and heated, a reflective film containing silver as a main component and containing tin is obtained. Since the reflective film containing tin has high adhesion to inorganic oxides such as glass and ITO (indium tin oxide), the reflective film formed using the dispersion of the present invention is difficult to peel off from the substrate.

  If the particle size (average diameter) of the metal particles is 100 nm or less, more preferably 10 nm or less, the particles can be sintered at a low heating temperature (for example, 150 ° C. or more and 220 ° C. or less) to form a reflective film. .

  The dispersion solvent has a nonpolar solvent, and the metal particles are highly dispersible with respect to such a dispersion solvent. Therefore, the metal particles are uniformly dispersed in the dispersion. Therefore, when the dispersion liquid is ejected from the nozzles of the ink jet printer to form the coating layer, nozzle clogging does not occur, and a coating layer having a uniform concentration of metal particles can be formed.

  When a coating layer having a desired shape is formed, if a sputtering method is used to form the reflective film, a lithography process is required after the reflective film is formed, and the manufacturing process is complicated, resulting in high manufacturing costs. On the other hand, if an inkjet printer is used, a dispersion liquid can be discharged to a desired location to directly form a coating layer having a desired shape, so that a lithography process is not required and a reflective film can be easily manufactured.

  The first solvent used in the method for producing a dispersion of the present invention is difficult to use a low-boiling solvent, water or alcohol for the purpose of wetting metal particles or an adhesive plate, It is suitable to use high boiling solvents (oils) such as organic esters and alcohols having 5 or more carbon atoms.

  In the step of producing the dispersion of the present invention, the first solvent is replaced with the second solvent because the vapor of the first solvent is modified when the metal particles are formed. This is for the purpose of reducing the amount of the first solvent remaining in the dispersion, in addition to the purpose of removing together with the first solvent.

  Since the first solvent has a boiling point higher than that of a low-boiling solvent, water or alcohol, if the first solvent remains in the dispersion, the heating temperature of the coating layer is low in the step of forming the reflective film. The film quality of the reflective film is deteriorated without being removed. Therefore, if the amount of the first solvent is removed in the step of producing the dispersion, a reflective film with good film quality can be obtained.

  The metal particles are difficult to disperse in the polar solvent, but the dispersibility with respect to the nonpolar solvent is high. Therefore, if the second solvent is replaced with the third solvent, the metal particles do not aggregate and the third solvent is the dispersion solvent. A dispersion liquid uniformly dispersed in the solvent is obtained.

  If the dispersion liquid of this invention is used, the reflector of a desired shape can be manufactured easily and the manufacturing cost is also cheap. The reflector manufactured according to the present invention hardly peels off from the substrate and has high heat resistance and weather resistance. Therefore, if the reflector is used for an LCD, a highly reliable LCD can be obtained.

Reference numeral 1 in FIG. 1 shows a manufacturing apparatus used for manufacturing the metal particles of the present invention, and the manufacturing apparatus 1 has a vacuum chamber 2.
An evacuation system 7, a gas supply system 8, and a solvent supply system 6 are connected to the vacuum chamber 2, and the vacuum evacuation system 7 is operated to evacuate the inside of the vacuum chamber 2. The atmosphere is removed to form a vacuum atmosphere.

  While continuing evacuation, an inert gas is supplied from the gas supply system 8 into the vacuum chamber 2 and a first solvent is supplied from the solvent supply system 6. The first solvent 12 supplied into the vacuum chamber 2 is exposed to the internal atmosphere of the vacuum chamber 2 to evaporate, and the vapor is released into the vacuum chamber 2.

  Continue evacuation and supply of inert gas, the total pressure is less than 1 atm (101.325 Pa) inside the vacuum chamber 2, the partial pressure of the inert gas is 10 Torr or less, and the first solvent is saturated vapor pressure A vapor atmosphere is formed.

  A metal material 3 is disposed on the bottom wall side inside the vacuum chamber 2, and an adhesion plate 5 is disposed on the ceiling side inside the vacuum chamber 2 with the surface facing the metal material 3. The first solvent is composed of a high boiling point solvent such as an organic ester or an alcohol having 5 or more carbon atoms, and the first solvent is in a saturated state in a steam atmosphere. If the temperature is lower than that, the surface of the adhesion plate 5 becomes wet.

  The manufacturing apparatus 1 has a heating means (not shown). For example, the heating means is composed of an electron beam gun, and the metal material 3 is heated when the electron beam is irradiated from the heating means toward the surface of the metal material 3 facing the attachment plate 5 while maintaining the vapor atmosphere. The vapor of the metal material is released toward the adhesion plate 5.

  The vapor of the metal material reaches the adhesion plate 5 after being decelerated by the inert gas. Since the surface of the adhesion plate 5 is wet with the first solvent, the film growth by the vapor of the reached metal material is hindered, and the metal material fine particles (metal particles) having a particle size of 100 nm or less on the surface of the adhesion plate 5 Is formed.

After heating the metal material 3 for a predetermined time, the heating of the metal material 3, introduction of inert gas, and evacuation are stopped, and the adhesion plate 5 is taken out of the vacuum chamber 2.
The metal particles on the adhesion plate 5 are covered with the first solvent, and when the surface of the adhesion plate 5 is washed with the first solvent, the metal particles are peeled from the adhesion plate 5 together with the first solvent, A first treatment liquid containing one solvent and metal particles is obtained.

  If a second solvent (for example, a polar solvent) that easily separates the first solvent from the metal particles is added to the first treatment liquid, and the first solvent is replaced with the second solvent, the metal particles and the second solvent A second treatment liquid having the above solvent is obtained.

  Next, when the second solvent is replaced with a third solvent containing a nonpolar solvent, a dispersion having metal particles and a third solvent is obtained. Since the metal particles are highly dispersible in the nonpolar solvent, the metal particles do not aggregate in the third solvent, and the particles are dispersed uniformly and independently.

  In the case where an alloy material containing silver as a main component and 0.1 to 5% by weight of tin is used as the metal material 3, silver is the main component and tin is 0.1 to 5% by weight. % Of the metal particles contained in the dispersion solvent (third solvent) is obtained.

  Further, when the metal material 3 contains silver as a main component and tin is not contained, an organic tin compound is added to the dispersion so that the content of tin with respect to silver is 0.1 wt% or more and 5 wt% or less. The dispersion of the second example of the present invention, in which metal particles mainly composed of silver are dispersed in a dispersion solvent, and an organic tin compound is added so that the content of tin with respect to silver is 0.1 wt% or more and 5 wt% or less A liquid is obtained. Here, the content of tin with respect to silver is the content of tin in the metal component contained in the dispersion, that is, the total of the weight of metal particles and the polymerization of tin is subtracted from the weight of tin. Therefore, the range of the content of tin with respect to silver is the same in both dispersions of the first and second examples.

  Next, an example of a process for producing a reflector using the dispersion liquid of the present invention will be described. Reference numeral 11 in FIG. 2A denotes a substrate. The dispersion liquid is filled in a tank of an inkjet printer, the nozzle of the inkjet printer is directed toward the surface of the substrate 11, and the nozzle is directed toward a predetermined position on the surface of the substrate 11. Then, the dispersion liquid is discharged, and a coating layer 12 having a predetermined shape is formed at a predetermined portion of the substrate 11 (FIG. 2B).

  Next, when the coating layer 12 is heated, the third solvent evaporates and is removed from the coating layer 12, and the metal particles are sintered to form a metal material film (reflective film) having a predetermined shape. Reference numeral 10 in FIG. 2C denotes a reflector having a reflective film 15 formed on the surface of the substrate 11.

  Since the reflective film 15 is mainly composed of silver, the reflectance of light (visible light) is high. In the case of using any of the dispersion liquids of the first and second examples, the content of tin in the reflective film 15 is 0.1 wt% or more and 5 wt% or less, and such a reflective film 15 is an inorganic oxide. Therefore, when the inorganic oxide (silicon dioxide) is exposed on the surface of the substrate 11 like a glass substrate, the reflective film 15 is strongly adhered to the substrate 11.

  When the reflective film 15 is strongly bonded to the substrate 11, it is difficult to peel off from the substrate 11 even when subjected to a thermal load. Therefore, the reflector 10 manufactured according to the present invention is excellent in heat resistance and weather resistance. Therefore, the reflective LCD using the reflector 10 is highly reliable.

  Using metal material 3 made of silver and a first solvent made of α-terpineol, metal particles are formed under the condition that the partial pressure of the inert gas (helium gas) is 0.5 Torr, and the particle diameter (average diameter) Produced a first treatment liquid containing 20% by weight of metal particles having a diameter of about 10 nm.

  As the second solvent, a polar solvent (acetone) having a higher specific gravity than the first solvent is used without dissolving the first solvent, and 5 volumes of the second solvent are used for 1 part by volume of the first treatment liquid. Part addition, after stirring, let stand for 2 hours, separate the first treatment liquid into a lower layer having the second solvent and metal particles, and an upper layer mainly composed of the first solvent, collecting only the lower layer, The upper layer was removed (cleaning step).

  This washing process was repeated 5 times to replace the first solvent with the second solvent, and a second treatment liquid was obtained. Metal particles were precipitated in the second treatment liquid, and a third solvent composed of tetradecane was added to the precipitate, and the second solvent was replaced with the third solvent. Further, tin dioctoate, which is an organic tin compound, was added to obtain a dispersion of the second example of the present invention having a tin content of 0.1% by weight and a tetradecane concentration of 60% by weight.

  The content of Ag in the dispersion liquid of the second example obtained in the above step was 18% by weight of the whole, the viscosity was 7 mPa · s, and the surface tension was 32 mN / m. Further, this dispersion was very stable, and no settling and separation of metal particles was observed even after 1 month at room temperature.

  The dispersion liquid of the second example is applied to the surface of a non-alkali glass substrate for liquid crystal by a spin coating method to form a coating layer, which is baked in the atmosphere at a heating temperature of 220 ° C. for a heating time of 30 minutes. A reflective film 15 of 200 nm was formed, and the reflector 10 of Example 1 was obtained.

  Separately from this, in place of the dispersion of the second example, a dispersion containing no tin (Ag nanometal ink manufactured by Vacuum Metallurgical Co., Ltd.) was used. A reflector was created. Furthermore, reflectors of Examples 2 to 6 and Comparative Examples 2 and 3 were prepared by changing the content of tin in the dispersion liquid of the second example with respect to silver.

  The contents of Examples 1 to 6 and Comparative Examples 1 to 3 with respect to silver are described in the “Sn (% by weight)” column of Table 1 below.

The “specific resistance” and “reflectance” of the reflectors 10 of Examples 1 to 6 and Comparative Examples 1 to 3 were measured under the following conditions, and the following “adhesion” test was performed using each reflector 10. went.
<Resistivity>
The resistance value was measured with a 4-probe resistance measuring instrument (trade name “Loresta” manufactured by Mitsubishi Chemical Corporation).

<Reflectance>
The reflectance in the visible light region (wavelength 400 to 800 nm) was measured using a spectrophotometer.
<Adhesion>
According to the cross cut method, the surface of the reflective film 15 was cut into 6 pieces vertically and horizontally with a cutter to form 25 5 mm square cells (5 × 5). After sticking an adhesive tape (trade name “2422” manufactured by 3M) on the surface of the reflective film 15 having the grids, the adhesive tape was peeled from the reflective film 15 and the peeling of the reflective film 15 was observed. Table 1 shows the number of squares in which the reflective film 15 was not peeled in 25 squares.

  As apparent from Table 1 above, when the content of tin with respect to silver was 0.1% by weight or more, the adhesion was high. As the content of tin with respect to silver increased, the adhesion improved, but when the content exceeded 5% by weight, not only the specific resistance increased, but also the reflectance decreased to less than 90%. From these facts, it is understood that if the content of tin in the reflective film 15 is 0.1 wt% or more and 5 wt% or less, the effect of improving the adhesion can be obtained without impairing the specific resistance and reflectivity. It was.

Next, another embodiment of the present invention will be described.
The dispersion liquid of the present invention is not limited to the case where tin is contained in the metal particles as described above or the case where it is contained as an organic tin compound. For example, in a dispersion in which metal particles mainly containing silver are dispersed, other metal particles mainly containing tin are added so that the content of tin with respect to silver is 0.1 wt% or more and 5 wt% or less. In addition, it may be added.

  Furthermore, an organic tin compound or tin particles are added to the dispersion of the first example so that the content of tin with respect to silver is 0.1 wt% or more and 5 wt% or less, or the content of tin with respect to silver is You may add the metal particle which has a tin as a main component to the dispersion liquid of a 2nd example so that it may become 0.1 to 5 weight%.

  The organotin compound may be added to the dispersion after the second solvent is substituted, or the final dispersion tin will have a silver content of 0.1 wt% to 5 wt%. If it is, you may add an organotin compound in the process in the middle of manufacturing a dispersion liquid.

  Although the method for forming the metal particles is not particularly limited, as described above, according to the gas evaporation method in which the metal particles are formed in the presence of the first solvent vapor and an inert gas, the particle size is 100 nm or less, Metal fine particles having a uniform particle size can be obtained. The particle size of the metal particles is not particularly limited, but if the particle size is 100 nm or less, more preferably 10 nm or less, a reflective film having a high reflectance can be obtained even when the heating temperature of the coating layer is low.

  When the metal particles are produced by the gas evaporation method, the location of the first solvent is not particularly limited. For example, if the first solvent is disposed at a position where it does not come into contact with the metal material 3, a new first solvent is supplied into the vacuum chamber 2 while discharging the first solvent from the vacuum chamber 2. The first solvent may be circulated in the vacuum chamber 2. Further, the first solvent is not disposed in the same vacuum chamber 2 as the metal material 3, but the vapor of the first solvent is generated in another device, and this vapor is introduced into the vacuum chamber 2. Also good.

  The method for heating the metal material 3 is not particularly limited. For example, the metal material 3 is disposed close to a magnetic flux generation means such as a coil, and a high-frequency current is passed through the magnetic flux generation means to generate a magnetic field passing through the metal material 3. Then, a high-frequency induction heating method can be used in which a current is passed through the metal material 3 to generate heat.

  The type of organotin compound used in the dispersion liquid of the second example is not particularly limited, but is a liquid at room temperature and is dispersed or dissolved in the solvent (second and third solvents) in the dispersion liquid. And what decomposes | disassembles at the heating temperature (for example, 150 to 220 degreeC) of an application layer is preferable.

Examples of the organic tin compound that can be used in the present invention include tetrabutyltin, tetraphenyltin, tetrapropyltin, dibutyldiphenyltin, and tributylacetoxytin. One of these organotin compounds may be used alone in the second dispersion, or two or more thereof may be used in the same second dispersion.
The kind of the inert gas is not limited to helium gas, and neon gas, argon gas, xenon gas, krypton gas, or the like can be used.

  Further, instead of collecting only the metal particles adhering to the adhering plate 5, the metal particles adhering to the inner wall of the vacuum chamber 2 may be collected, or without providing the adhering plate 5 in the vacuum chamber 2, the vacuum chamber 2. Only metal particles adhering to the inner wall may be collected.

  In the method for producing a dispersion of the present invention, a dispersant for improving the dispersibility of metal particles can be added to the first treatment liquid and / or the dispersion as necessary. When a dispersant is added to the dispersion, a dispersant that does not dissolve in the first solvent can also be used.

  The dispersant that can be used in the dispersion is not particularly limited, and one or more selected from alkylamines, carboxylic acid amides, and aminocarboxylates are used. In particular, the alkylamine is preferably an alkylamine having a main skeleton having 4 to 20 carbon atoms, and more preferably an alkylamine having a main skeleton having 8 to 18 carbon atoms from the viewpoint of stability and handling properties.

  When the number of carbon atoms in the main chain of the alkylamine is less than 4, there is a problem that the basicity of the amine is too strong and the metal particles tend to be corroded, and eventually the metal particles are dissolved. Further, when the number of carbon atoms in the main chain of the alkylamine exceeds 20, when the concentration of metal particles in the dispersion is increased, there is a problem that the viscosity of the dispersion is increased and the handling property is slightly inferior. Moreover, although all series of alkylamines work effectively as a dispersant, primary alkylamines are preferably used from the viewpoints of stability and handling properties.

  Specific examples of alkylamines include primary amines such as butylamine, octylamine, dodecylamine, hexadodecylamine, octadecylamine, cocoamine, tallowamine, hydrogenated tallowamine, oleylamine, laurylamine, stearylamine, and the like, Secondary amines such as dicocoamine, dihydrogenated tallowamine, distearylamine, and the like, and dodecyldimethylamine, didodecylmonomethylamine, tetradecyldimethylamine, octadecyldimethylamine, cocodimethylamine, dodecyltetradecyldimethylamine, and Tertiary amines such as trioctylamine and others, as well as naphthalenediamine, stearylpropylenediamine, octamethylenediamine, and nonanediamine. There is a diamine. Specific examples of carboxylic acid amides and aminocarboxylic acid salts include, for example, stearic acid amide, palmitic acid amide, lauric acid lauryl amide, oleic acid amide, oleic acid diethanolamide, oleic acid lauryl amide, stearanilide, and oleylaminoethyl. There is glycine. One or more of these alkylamines, carboxylic acid amides and aminocarboxylates can be used, thereby acting as a stable dispersant.

  The alkylamine content is approximately 0. 1 wt% or more and 10 wt% or less, preferably 0. The range is from 2% by weight to 7% by weight. When the content of alkylamine is less than 0.1% by weight, the metal particles may not be dispersed in an independent state, and aggregates may be generated. When the content exceeds 10% by weight, There is a problem that the viscosity becomes high, a gel-like material is finally formed, and the coating layer formability is poor.

  The first solvent is a metal particle generating solvent used in the gas evaporation method, and is a solvent having a relatively high boiling point in order to make the adhered plate wet. As the first solvent, alcohols having 5 or more carbon atoms such as terpineol, citronol, geraniol and phenethyl alcohol, and organic esters such as benzyl acetate, ethyl stearate, methyl oleate, ethyl phenylacetate and glyceride should be used. These solvents may be used alone as the first solvent, or two or more may be used as the same first solvent. The type of the first solvent can be selected as appropriate depending on the constituent elements of the metal particles used or the application of the dispersion.

If the first solvent cannot be replaced by the third solvent and the first solvent is not separated from the metal particles, before adding the third solvent, use a second solvent that can be replaced with the third solvent. The first solvent may be replaced.
The second solvent may be any one that can precipitate the metal particles in the treatment liquid and separate the first solvent, and includes a polar solvent having a molecular weight lower than that of the first solvent, such as acetone.

  The third solvent, which is the dispersion medium of the dispersion liquid, is liquid at room temperature such as nonpolar hydrocarbons having 6 to 20 carbon atoms in the main chain, water, or alcoholic solvents having 15 or less carbon atoms. At least one kind can be selected and used. In the case of nonpolar hydrocarbons, if the number of carbon atoms is less than 6, there is a problem in the handling of the dispersion because the drying of the dispersion is too early, and if the number of carbons exceeds 20, the viscosity of the dispersion increases. In addition, there is a problem that carbon tends to remain in the heating process of the coating layer. When alcohol is used as the third solvent, if the number of carbons exceeds 15, there is a problem that carbon tends to remain in applications where the viscosity of the dispersion is increased or firing is performed.

  Examples of the third solvent include long-chain alkanes such as hexane, heptane, octane, decane, undecane, dodecane, tridecane, tetradecane, and trimethylpentane, cyclic alkanes such as cyclohexane, cycloheptane, and cyclooctane, benzene, toluene, Aromatic hydrocarbons such as xylene, trimethylbenzene, and dodecylbenzene, and alcohols such as hexanol, heptanol, octanol, decanol, cyclohexanol, and terpineol can be used. These solvents may be used alone or in the form of a mixed solvent. For example, it may be a mineral spirit that is a mixture of long-chain alkanes.

  The concentration of the metal particles in the dispersion is not particularly limited, but is preferably 10% by weight to 70% by weight, more preferably 10% by weight to 60% by weight. If the concentration is less than 10% by weight, the viscosity and surface Although ink properties such as tension are sufficiently satisfied, it is not suitable for forming a reflective film, and when the concentration exceeds 70% by weight, ink properties such as viscosity and surface tension are not satisfied. Can not.

  The coating method of the dispersion liquid is not particularly limited, and generally used coating methods such as a bar coating method can be widely used in addition to the ink jet method and the spin coating method described above. When applying the dispersion liquid by the inkjet method, considering the supply stability of the dispersion liquid to the printer head, the droplet formation property of the dispersion liquid, the discharge stability of the dispersion liquid, the high-speed response of the printer head, etc. In a normal operating environment (environment temperature is 0 ° C. or more and 50 ° C. or less), the viscosity of the dispersion is 1 mPa · s or more and 100 mPa · s or less, preferably 1 mPa · s or more and 10 mPa · s or less, and the surface tension is 25 mN / m or more and 80 mN or less. / M or less, preferably 30 mN / m or more and 60 mN / m or less, and the dispersion of the present invention satisfies such characteristics.

  As the use of the dispersion liquid of the present invention, there are various uses such as a conductive circuit formation in addition to the reflection film formation use. In the present invention, it is possible to achieve the purpose of producing a reflective film by using it as an ink composition, particularly an inkjet ink in a low-cost, high-performance inkjet printer that has recently been widely used as a peripheral device for personal computers.

  The physical properties such as viscosity and surface tension required as ink characteristics of the ink jet ink are as described above. In addition, the selection conditions for the dispersion solvent are determined by the difference in usage, such as selecting polar solvents such as water and alcohols and non-polar hydrocarbon solvents according to the properties of the substrate such as the glass substrate or plastic substrate to be used. There is a case.

  The substrate 11 on which the reflective film 15 is formed is not limited to a glass substrate. If the substrate 11 has an inorganic oxide exposed at a portion where the reflective film 15 is to be formed, for example, a ceramic substrate or a substrate having an inorganic oxide layer formed on the surface of a plastic substrate may be used. it can. The inorganic oxide layer to which the reflective film 15 is in close contact is not limited to the silicon dioxide layer. For example, the reflective film 15 may be formed in close contact with an ITO (indium tin oxide) layer.

  After the dispersion liquid of the present invention is applied and dried to form a reflective film, the dispersion liquid of the present invention is applied to the reflective film and dried to form a reflective film having two or more layers. One reflective film can also be formed with a film. This method is useful for ensuring the adhesion between the substrate 11 and the reflective film.

Sectional drawing explaining an example of the manufacturing apparatus used for this invention (A)-(c): Sectional drawing explaining an example of the manufacturing process of the reflector by this invention

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Manufacturing apparatus 2 ... Vacuum chamber 3 ... Metal material 5 ... Adhering plate 7 ... Vacuum exhaust system 8 ... Gas supply system 10 ... Reflector 11 ... Substrate 12 ... Coating layer 15 ... Reflection film

Claims (10)

A dispersion for forming a reflection film in which metal particles mainly composed of silver are dispersed in a dispersion solvent, coated on an inorganic oxide, and heated to form a reflection film,
Contains a nonpolar solvent and an organic tin compound,
A dispersion containing 0.1 wt% or more and 5 wt% or less of tin with respect to the total weight of silver and tin contained in the dispersion.   The dispersion according to claim 1, wherein the metal particles have a particle size of 100 nm or less.   The dispersion according to any one of claims 1 and 2, wherein one or both of xylene and tetradecane are contained as the nonpolar solvent. A metal material mainly composed of silver is evaporated in a vapor atmosphere containing an inert gas to produce metal particles,
Contacting the vapor of the first solvent with the surface of the metal particles, forming a film of the first solvent on the surface of the metal particles;
Substituting the second solvent with the first solvent to create a treatment liquid having the metal particles and the second solvent,
The second solvent is replaced with a third solvent containing a nonpolar solvent, and tin is contained in the range of 0.1 wt% to 5 wt% with respect to the total weight of silver and tin contained. The method for producing a dispersion according to claim 1, wherein the organotin compound is added as described above to disperse the metal particles.   The method for producing a dispersion according to claim 4, wherein the metal material contains tin.   The method for producing a dispersion according to any one of claims 4 and 5, wherein one or both of an alcohol or an organic ester having 5 or more carbon atoms is used as the first solvent.   The method for producing a dispersion according to claim 6, wherein α-terpineol is used for the alcohol having 5 or more carbon atoms.   The method for producing a dispersion according to any one of claims 4 to 7, wherein a polar solvent is used as the second solvent.   The method for producing a dispersion according to claim 8, wherein the polar solvent is acetone. The method for producing a dispersion according to any one of claims 4 to 9, wherein xylene and / or tetradecane are used as the nonpolar solvent.

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