JP2012207049A - Colloidal dispersion liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a colloidal dispersion liquid which includes an inorganic component including metal particles, and a dispersion medium comprising a photo-curable organic compound, and is excellent in well-balanced ink dischargeability and dispersibility.SOLUTION: The colloidal dispersion liquid includes: an inorganic component including metal particles with an average particle diameter of 0.7-200 nm; an organic substance including at least an amine, and coating at least a portion of surfaces of the metal particles; a dispersion medium including a photo-curable organic compound with a (meth)acryloyl group; and a carboxylic acid.

Description

  The present invention relates to a colloidal dispersion liquid including a dispersion medium and metal particles dispersed in the dispersion medium, and more particularly to a colloidal dispersion liquid that can be suitably used as an ink in an ink jet system, a gravure system, or a flexo system printing system.

  A colloidal dispersion liquid containing a dispersion medium and inorganic particles such as metal particles dispersed in the dispersion medium can be used for printing by forming metal particles into fine particles and can be used for printing. It has been. In particular, colloidal dispersions using metal particles have been conventionally required to have good dispersibility. In colloidal dispersions with inferior dispersibility, metal particles settle in containers, ink tanks, ink paths, etc. during storage and use, resulting in printing defects and reduced printing characteristics. It is because it ends.

  Here, particularly from the viewpoint of preventing sedimentation of the metal particles, the viscosity of the colloidal dispersion is increased by using a high-viscosity photosensitive organic substance or a high-viscosity solvent, thereby making the metal particles difficult to settle. Has been proposed.

  For example, in Patent Document 1 (Japanese Patent Laid-Open No. 2004-54085), a photosensitive organic paste is intended to supply a photosensitive conductive paste that is a thick film with good light transmittance and that can be processed in a rectangular and fine manner. There has been proposed a photosensitive conductor paste characterized in that it contains a component and a metal powder as essential components and contains metal fine particles having a particle diameter of 0.4 μm or less in a range of 10 wt% to 100 wt% of the total amount of the metal powder. Yes.

  More specifically, metal particles having a small particle size of 0.4 μm or less are dispersed in a solvent (also referred to as a dispersion medium) containing a photosensitive organic component having a high viscosity to form a paste, and have a high viscosity of 1 to 5 Pa · s. Is used for screen printing as an ink (see Patent Document 1, paragraph numbers [0040] [0041]).

  Further, for example, Patent Document 2 (Japanese Patent Laid-Open No. 2006-30385) and Patent Document 3 (Japanese Patent Laid-Open No. 2010-161127) also include metal particles having a small particle diameter and a photosensitive organic material as a dispersion medium. It has been studied to use a photosensitive inorganic paste having a viscosity for screen printing.

JP 2004-54085 A JP 2006-30385 A JP 2010-161127 A

  However, the high-viscosity paste based on the technique proposed in Patent Documents 1 to 3 has a problem that it is not preferable to use it as an ink in a printing system such as an inkjet system, a flexo system, a gravure system, and an offset system. . This is because, for example, when ink made of a high-viscosity paste is used in the ink jet system, ink ejection from the nozzle becomes unstable. In addition, even when using an ink made of a high-viscosity paste in a printing method that uses a plate, such as a flexo method, a finely drawn portion or a solid portion pattern is not printed well, and the print quality deteriorates. . When such a high-viscosity paste is diluted with a low-viscosity solvent, the components easily settle, resulting in problems such as poor print quality and clogging of ink jet nozzles.

  In consideration of printing characteristics, it is desirable to use metal particles having a small particle diameter (metal fine particles) as proposed in Patent Documents 1 to 3, but such fine particles may have different polarities such as the polarity of the dispersion medium. It is sensitive to the surrounding environment and easily agglomerates. Especially, photosensitive organic substances have polymerizable functional groups such as acryloyl group or methacryloyl group and other various functional groups. It tends to promote agglomeration. That is, conventionally, in a colloidal dispersion liquid containing a dispersion medium composed of an inorganic component containing metal particles and a photocurable organic compound, it has been difficult to achieve both ink jetting properties and dispersibility.

  In view of the problems in the prior art as described above, an object of the present invention is to include a dispersion medium composed of an inorganic component containing metal particles and a photocurable organic compound, and a colloidal dispersion excellent in ink dischargeability and dispersibility in a balanced manner. To provide liquid. More specifically, the object of the present invention includes a dispersion medium composed of an inorganic component containing metal particles and a photocurable organic compound, and is dispersed even if the viscosity is low enough not to impair the ejection stability of the ink. The object of the present invention is to provide a colloidal dispersion having good properties and in which metal particles are difficult to settle.

  As a result of earnest research on the dispersion medium to achieve the above object, the present inventor includes a dispersion medium composed of an inorganic component containing metal particles and a photocurable organic compound, and is excellent in ink dischargeability and dispersibility in a well-balanced manner. In order to obtain a colloidal dispersion liquid, it was found that the use of an amine localized on at least a part of the surface of metal particles was extremely effective in achieving the above object, and the results of repeated experiments The present invention has been reached.

That is, the present invention
An inorganic component containing metal particles;
An organic substance containing at least an amine covering at least a part of the surface of the metal particles;
A dispersion medium containing a photocurable organic compound;
Including
A colloidal dispersion is provided.

  In other words, the colloid dispersion liquid of the present invention includes a solid content mainly composed of colloidal particles composed of metal particles and an organic substance, and a dispersion medium for dispersing the solid content. The “medium” disperses the solid content in the colloidal dispersion, but a part of the solid content may be dissolved in the “dispersion medium”. The “main component” means a component having the highest content among the constituent components.

  In the colloidal dispersion liquid of the present invention having such a configuration, a clear reason such as a mechanism is not clear, but it is presumed that the following mechanism is generally functioning. That is, in an amine, an amino group has a relatively high polarity and easily causes an interaction due to a hydrogen bond, but a portion other than the amino group has a relatively low polarity. In addition, amino groups tend to exhibit alkaline properties. Therefore, when the organic substance containing such an amine covers at least a part of the surface of the metal particle, the organic substance having a portion having a different polarity exhibits a function of sufficiently making the dispersion medium and the metal particle have an affinity. As a result, even if the viscosity of the dispersion medium is low, the dispersion state of the metal particles in the dispersion medium is relaxed from sensitively changing depending on the properties of the dispersion medium, and aggregation and settling between the metal particles is suppressed. It is assumed that the dispersibility of the particles is remarkably improved, so that the colloidal dispersion liquid of the present invention can exhibit good dispersibility even if a dispersion medium having a low viscosity is used so as not to impair the inkjet dischargeability. Is done.

  In addition, since the colloidal dispersion of the present invention is excellent in the dispersibility of the metal particles and the inkjet dischargeability, the metal particles are aggregated when the colloidal dispersion is applied on a substrate (particularly when applied by an inkjet method). The coating is contained in a state in which the metal particles and the base material are more densely packed by drying and firing because the contact point between the metal particles and the base material is increased. Thus, a film having excellent adhesion to the substrate can be obtained.

  Here, “dispersibility” in the present invention indicates whether or not the dispersion state of metal particles (or colloidal particles, hereinafter the same) in a colloidal dispersion is excellent (whether or not it is uniform). Furthermore, for example, it is an indicator that can be called “low sedimentation aggregation” indicating whether or not the dispersion state of the metal particles in the colloidal dispersion is maintained after a predetermined time.

  This “dispersibility” refers to a solid content mainly composed of colloidal particles composed of metal particles and organic matter from the colloidal dispersion of the present invention, or a dispersion or colloidal dispersion containing the prepared metal particles. A mixture obtained by taking out and mixing the solid content and the dispersion medium (for example, stirring with a spatula or the like, or irradiating ultrasonic waves with an ultrasonic homogenizer having an appropriate output) may be contained in a container. In addition, it can be evaluated by allowing to stand for a predetermined period and visually observing the presence or absence of precipitation and the state of the supernatant.

  The “solid content” of the colloidal dispersion is obtained from the colloidal dispersion (or a dispersion containing metal particles) after, for example, alcohol addition, centrifugation, aggregation, sedimentation, and removal of alcohol and dispersion medium by decantation. The main component is colloidal particles composed of inorganic particles and organic matter, and usually contains inorganic particles, residual organic matter and residual reducing agent.

  Further, “dispersibility” can be evaluated by color tone because plasmon absorption occurs when metal particles are made of, for example, gold, silver, or copper. When plasmon absorption occurs, it can be determined that the metal particles are well dispersed in the form of fine particles, and when plasmon absorption does not occur, it is determined that the metal particles are aggregated and inferior in dispersibility. Can do.

  In addition, “inkjet dischargeability” in the present invention means a low viscosity (for example, 1 mPa · s to 100 mPa · s) at which a colloidal dispersion of the present invention can be stably discharged as an ink using a commercially available inkjet printer. It means having. With such a low-viscosity colloidal dispersion, a commercially available ink jet printer can be used to discharge with good reproducibility when ejected in a dot pattern that does not overlap in front, back, left, and right at even intervals. It is possible to suppress problems such as the occurrence of minute scattering (satellite) around.

  In the colloidal dispersion liquid of the present invention, the photocurable organic compound is preferably an ultraviolet curable monomer having an acryloyl group or a methacryloyl group.

  According to such a configuration, since the ultraviolet curable monomer has a low viscosity, the inkjet discharge property of the colloidal dispersion is improved, and the colloidal dispersion of the present invention containing the ultraviolet curable monomer is used as a basis. When coated on the material, a film is formed in a state where the metal particles are well dispersed, and the carbon-carbon double bonds in the molecule are polymerized by ultraviolet rays to form a three-dimensional network. A film having excellent adhesion can be obtained.

  Moreover, in the colloid dispersion liquid of the present invention, it is preferable that the average particle diameter of the metal particles is 0.7 nm to 200 nm. If it is 0.7 nm or more, a colloidal dispersion capable of forming a good film can be obtained more reliably, and the production of metal particles is practical without increasing the cost. The dispersibility is less likely to change over time, and the ink jetting properties are even better.

  Here, the average particle diameter of the metal particles in the colloidal dispersion of the present invention refers to that which can be measured by a dynamic light scattering method or a small angle X-ray scattering method.

  The colloidal dispersion of the present invention preferably has a viscosity of 1 mPa · s to 100 mPa · s. According to such a configuration, a wide range of methods can be applied as a method of coating a colloidal dispersion on a substrate or a method of drawing on a substrate using a colloidal dispersion. There is a merit that it is excellent. The viscosity of the colloidal dispersion of the present invention is measured with a vibration viscometer (for example, VM-100A-L manufactured by CBC Corporation).

  Furthermore, it is preferable that the colloid dispersion liquid of the present invention further contains a carboxylic acid as an organic substance. Similarly to the amino group of the amine, the carboxyl group of the carboxylic acid has a relatively high polarity and easily causes an interaction due to a hydrogen bond, but a portion other than the carboxyl group has a relatively low polarity. In addition, the carboxyl group easily exhibits acidic properties, and can react with the amino group to form an amide group, so that the affinity with the amino group is high. When an organic substance containing an amine and a carboxylic acid covers at least a part of the surface of the metal particle in a complicatedly mixed state, the diversity of the organic substance having a portion having a different polarity is increased. It is presumed that the affinity of is further increased. As a result, the dispersion state of the metal particles in the dispersion medium is alleviated more sensitively depending on the properties of the dispersion medium, and in order to suppress aggregation and settling between the metal particles, The dispersibility of the metal particles is further remarkably improved. Therefore, the colloidal dispersion liquid of the present invention can exhibit remarkably good dispersibility even when a dispersion medium having a low viscosity is used so as not to impair the ink jet discharge performance. Presumed to be.

  In the above colloidal dispersion of the present invention, the amine preferably has 3 or more carbon atoms per amino group. If the number of carbon atoms of the amine is 3 or more per amino group, the contribution of the amino group to the chemical properties of the organic matter will not be too great, and the polarity and reactivity will not increase, and excellent dispersibility Is obtained.

  The present invention also relates to an ink for an ink jet system, a gravure system, or a flexo system containing the colloidal dispersion liquid of the present invention. As described above, the colloidal dispersion of the present invention has a low viscosity, excellent ink jet ejection properties, and excellent dispersibility. Therefore, when used in these types of inks, stable printing is possible.

  According to the present invention, it is possible to provide a colloidal dispersion liquid that includes a dispersion medium composed of an inorganic component containing metal particles and a photocurable organic compound, and is excellent in ink dischargeability and dispersibility in a well-balanced manner. More specifically, according to the present invention, a dispersion medium comprising an inorganic component containing metal particles and a photocurable organic compound is included, and even if the viscosity is low enough not to impair ink ejection stability. It is possible to provide a colloidal dispersion having good properties and in which metal particles are difficult to settle.

  Hereinafter, (1) a metal colloid dispersion as a preferred embodiment of the colloid dispersion of the present invention, (2) a preferred embodiment of the method for producing the metal colloid dispersion, and (3) the metal colloid dispersion The manufacturing method of the coating film using the liquid will be described in detail. In addition, in the following description, only one embodiment of the present invention is shown, and the present invention is not limited thereto, and redundant description may be omitted.

(1) Metal colloid dispersion First, a preferred embodiment of the colloid dispersion of the present invention will be described. The metal colloid dispersion of this embodiment is
Metal particles,
An organic substance containing an amine and a carboxylic acid covering at least a part of the surface of the metal particles;
A dispersion medium containing a photocurable organic compound,
A metal colloid dispersion liquid is provided.

  In the metal colloid dispersion liquid of this embodiment having such a configuration, a clear reason such as a mechanism is not clear, but when two kinds of organic substances having different properties such as an amine and a carboxylic acid are included, these organic substances are complicated. It is thought that it acts on. An amino group and a carboxyl group in one molecule of organic substances such as these have a relatively high polarity and are likely to cause an interaction due to a hydrogen bond, but portions other than the amino group and the carboxyl group have a relatively low polarity. . Furthermore, an amino group and a carboxyl group tend to exhibit alkaline properties and acidic properties, respectively. Originally, the dispersion state of the metal particles in the dispersion medium is considered to change sensitively depending on the properties of the dispersion medium. However, when at least a part of the surface of the metal particle is covered with an organic substance such as these mixed in a complicated manner, the orientation of the polar group is changed according to the nature of the dispersion medium, etc. It is presumed that the dispersed state in the medium is maintained. That is, it is presumed that the organic substance can sufficiently make the dispersion medium and the metal particles have good affinity, and the dispersibility of the metal particles is remarkably improved. That is, according to the metal colloid dispersion liquid of the present embodiment, the dispersibility of the metal particles in the metal colloid dispersion liquid can be improved because it contains a specific combination of organic substances and a specific combination of dispersion medium. Therefore, for example, even if the viscosity of the dispersion medium is lowered, the metal particles or the metal colloid particles are unlikely to settle and aggregate, and good dispersibility and inkjet discharge properties can be exhibited.

  Here, in the conventional metal colloid dispersion liquid containing a photosensitive organic substance as a dispersion medium, as described above, a proposal has been made to increase the viscosity and improve the dispersibility of the metal colloid dispersion liquid. Although the effect has been obtained, no specific study has been made on the combination with other organic substances, and there is still room for improvement from the viewpoint of the balance between dispersibility and inkjet discharge properties.

  On the other hand, the metal colloid dispersion liquid of the present embodiment includes the above-described “amine covering at least part of the surface of the metal particles and carboxylic acid” in addition to the “dispersion medium containing a photocurable organic compound”. Since the organic substance is included, the dispersibility of the metal particles is remarkably excellent, and good ink jet discharge properties can be exhibited. Moreover, since the metal colloid dispersion liquid of this embodiment is excellent in the dispersibility of a metal particle and inkjet discharge property, when the said metal colloid dispersion liquid is apply | coated on a base material (especially when apply | coating by an inkjet system), a metal particle Is discharged on the base material in a well-dispersed state that is difficult to agglomerate, increasing the contact points between the metal particles and the base material, and further including a state in which the metal particles are packed more densely by drying and firing. Thus, a film having excellent adhesion to the substrate is obtained.

  For example, the present inventors take out a solid content mainly composed of metal colloidal particles composed of metal particles and an organic substance from a dispersion containing metal particles, mix the solid content and the dispersion medium, and The metal colloid dispersion liquid of the embodiment is prepared and allowed to stand in a container, and the metal of this embodiment is compared with the conventional metal colloid dispersion liquid by an evaluation method in which the presence or absence of precipitation and the state of the supernatant are visually observed. It has been confirmed that the colloid dispersion liquid (specifically, the metal colloid dispersion liquid of Examples described later) is excellent in dispersibility.

  In addition, the present inventors used a commercially available ink jet printer to evaluate the conventional colloidal metal dispersion using an evaluation method for discharging the colloidal metal dispersion liquid of the present embodiment with a dot pattern that does not overlap at the front, rear, left, and right at regular intervals. Compared to the liquid, it has been confirmed that the metal colloid dispersion liquid of this embodiment (specifically, the metal colloid dispersion liquid of the examples described later) is excellent in ink jet discharge properties.

  The metal colloid dispersion liquid of the present embodiment includes metal colloid particles in which metal particles described later are colloidalized as part of the solid content. Regarding the form of the metal colloid particles, for example, the surface of the metal particles Metal colloidal particles composed of organic substances, metal colloidal particles composed of the above metal particles as a core and coated with organic substances, and metal particles and organic substances mixed uniformly. The metal colloidal particles are not particularly limited. Among these, metal colloid particles in which metal particles are used as a core and the surface thereof is coated with an organic material, or metal colloid particles in which metal particles and an organic material are uniformly mixed are preferable. A person skilled in the art can appropriately prepare the metal colloid particles having the above-described form using a well-known technique in this field.

  In the metal colloid dispersion liquid of this embodiment, the preferable solid content is 1 to 70% by mass. When the solid content concentration is 1% by mass or more, the metal content in the metal colloid dispersion can be ensured, and the conductive efficiency does not decrease. In addition, when the solid content concentration is 70% by mass or less, the viscosity of the metal colloid dispersion liquid is not increased and the handling is easy, which is industrially advantageous. More preferably, the solid content concentration is 1 to 40% by mass, and still more preferably, the solid content concentration is 2 to 20% by mass.

  As used herein, the “solid content” of the metal colloid dispersion refers to aggregation, sedimentation, and decantation from the metal colloid dispersion (or dispersion containing metal particles), for example, by adding alcohol or centrifuging. The main component is colloidal particles composed of metal particles and organic substances, which are obtained after removal of the alcohol and dispersion medium by the above, and usually contain metal particles, residual organic substances and residual reducing agent.

  The viscosity of the metal colloid dispersion liquid of this embodiment is preferably in the viscosity range of 1 mPa · s to 100 mPa · s, more preferably in the viscosity range of 1 mPa · s to 50 mPa · s, and in the range of 2 mPa · s to 20 mPa · s. A viscosity range is particularly preferred. By setting the viscosity range, a wide range of methods can be applied as a method of applying a metal colloid dispersion on a substrate or a method of drawing on a substrate using a metal colloid dispersion. For example, dip method, screen method, spray method, bar coat method, spin coat method, ink jet method, dispenser method, brush method, casting method, flexo method, gravure method, syringe method, etc. Of these, the ink jet method can be preferably used. The viscosity can be adjusted by adjusting the solid content concentration, adjusting the blending ratio of each component, adding a thickener, and the like.

Here, as described above, the viscosity of the metal colloid dispersion liquid of this embodiment is measured by a vibration viscometer (for example, VM-100A-L manufactured by CBC Corporation). The measurement may be performed by immersing the liquid in the vibrator, and the measurement temperature may be normal temperature (20 to 25 ° C.).
Next, each component of the metal colloid dispersion liquid of this embodiment will be described.

(1-1) About metal particle Although it does not specifically limit as a metal particle of the metal colloid dispersion liquid of this embodiment, The electroconductivity of the film obtained using the metal colloid dispersion liquid of this embodiment is favorable. Therefore, it is preferable to use a (noble) metal having a smaller ionization tendency than zinc.

  Examples of the metal include at least one of gold, platinum, silver, copper, palladium, tin, nickel, and iron. Furthermore, the metal is preferably copper or at least one of gold (platinum), silver and copper, which has a smaller ionization tendency than copper (ie, noble). These metals may be used alone or in combination of two or more. As a method to be used in combination, there are a case where alloy particles containing a plurality of metals are used, and a case where metal particles having a core-shell structure or a multilayer structure are used.

  For example, when a silver colloid dispersion is used as the metal colloid dispersion, the conductivity of the coating formed using the metal colloid dispersion of this embodiment is good, but silver and other materials are considered in consideration of migration problems. By using a mixed colloidal dispersion liquid made of these metals, migration can be made difficult to occur. The “other metal” is preferably a metal in which the ionization column is more noble than hydrogen, that is, gold, copper, platinum, or palladium.

  Here, the average particle diameter of the metal particles (or metal colloid particles) in the metal colloid dispersion liquid of the present embodiment is not particularly limited as long as it does not impair the effects of the present invention. 0.7 nm to 200 nm is preferable, 1 nm to 100 nm is more preferable, and 2 nm to 50 nm is particularly preferable. If the average particle diameter of the metal particles is 0.7 nm or more, a metal colloid dispersion capable of forming a good film is obtained, and the production of the metal particles is practical without increasing the cost. Moreover, if it is 200 nm or less, the dispersibility of a metal particle is hard to change with time, and it is excellent also in inkjet discharge property, and preferable. In the case of discharging by an inkjet method, since large particles may hinder the discharge, it is more preferably 100 nm or less, and still more preferably 50 nm or less.

  In addition, the particle size of the metal particles in the metal colloid dispersion liquid of the present embodiment varies depending on the solid content concentration and is not necessarily constant. In addition, when the metal colloid dispersion includes a resin component, an organic solvent, a thickener, a surface tension adjuster, etc., which will be described later, as an optional component, it may contain a metal colloid particle component having an average particle size of more than 200 nm. A particle component having an average particle diameter of more than 200 nm may be included as long as the component does not cause sedimentation or particularly hinder the ejection of the ink jet and does not significantly impair the effects of the present invention.

  Here, the particle size of the metal particles in the metal colloid dispersion liquid of the present embodiment can be measured by a dynamic light scattering method or a small angle X-ray scattering method. In the examples described later, small-angle X-ray scattering is used, and more specifically, RINT-UltimaIII manufactured by Rigaku Corporation is used and 2θ is measured in the range of 0.1 to 4 ° by the transmission method. did. In this case, the sample was prepared by putting the metal colloid dispersion in a homemade cell made of acrylic resin with a thin polyimide film through which X-rays pass. Moreover, using NanoSolver (Ver.3.4) manufactured by Rigaku Denki Co., Ltd., and using the obtained scattering spectrum, the average size calculated by fitting a sphere as a scatterer model was taken as the particle size. However, in this method, since accurate measurement becomes difficult when it exceeds 50 nm, in that case, about 50 to 100 particles are taken from an electron micrograph taken using a scanning electron microscope manufactured by Hitachi, Ltd. The arithmetic average value of the particle size was taken as the particle size.

(1-2) Organic substance covering at least a part of the surface of the metal particle In the metal colloid dispersion liquid of the present embodiment, the organic substance covering at least a part of the surface of the metal particle, that is, the “organic substance” in the metal colloid particle is the above. The metal particles substantially constitute metal colloid particles and function as a dispersant for dispersing the metal particles in the dispersion medium. The organic substances include trace organic substances contained in the metal as impurities from the beginning, trace organic substances adhering to metal components mixed in the manufacturing process described later, residual reducing agents that could not be removed in the cleaning process, residual dispersants, etc. Thus, it is a concept that does not include organic substances or the like attached to metal particles in a small amount. The “trace amount” is specifically intended to be less than 1% by mass in the metal colloid particles.

  Since the metal colloid particles in this embodiment contain the organic substance, the dispersibility in the metal colloid dispersion liquid is high. Therefore, even if the content of the metal particles in the metal colloid dispersion liquid is increased, the metal colloid particles are difficult to aggregate, and as a result, good dispersibility is maintained.

  The organic substance is an organic substance that can coat metal particles to prevent aggregation of the metal particles and form metal colloidal particles, and the form of the coating is not particularly defined. From the viewpoints of properties and conductivity, an organic substance containing an amine and a carboxylic acid is used. In addition, when these organic substances are chemically or physically bonded to the metal particles, it is also considered that they are changed to anions and cations. In this embodiment, ions and complexes derived from these organic substances are used. Etc. are also included in the organic matter.

Examples of amines include monoamines and polyamines.
Monoamines include propylamine, isopropylamine, butylamine, pentylamine, hexylamine, heptylamine, n-octylamine and other octylamines, dodecylamine, oleylamine, octadecylamine, 2-ethoxyethylamine, 3-butoxypropylamine, 4 -Primary amines such as methoxybutylamine, cyclopentylamine, cyclohexylamine, aniline, secondary amines such as diethylamine, dipropylamine, diisopropylamine, dibutylamine, piperidine, hexamethyleneimine, tripropylamine, dimethylpropanediamine, And tertiary amines such as cyclohexyldimethylamine, pyridine, and quinoline.

  The polyamine corresponds to a polyamine corresponding to the above monoamine, for example, ethylenediamine, tetramethylenediamine, 1,3-propanediamine, N, N-dimethyl-1,3-diaminopropane, triethylenetetramine, piperazine, pyrimidine and the like. Examples include polyamines.

  The amine may be a compound containing a functional group other than an amine such as a hydroxyl group, a carboxyl group, an alkoxy group, a carbonyl group, an ester group, or a mercapto group. In this case, it is preferable that the number of nitrogen atoms derived from amine is equal to or greater than the number of functional groups other than amine. Moreover, the said amine may be used independently, respectively and may use 2 or more types together. In addition, the boiling point at normal temperature is preferably 300 ° C. or lower, more preferably 250 ° C. or lower.

  Moreover, it is preferable that carbon number of the said amine is 3 or more per amino group. If the number of carbon atoms of the amine is 3 or more per amino group, the contribution of the amino group to the chemical properties of the organic matter will not be too great, and the polarity and reactivity will not increase, and excellent dispersibility Is obtained. Furthermore, the number of carbon atoms of the amine is more preferably 4 or more per amino group.

  As the carboxylic acid, compounds having at least one carboxyl group can be widely used. For example, formic acid, oxalic acid, acetic acid, hexanoic acid, acrylic acid, octylic acid, oleic acid, pentanoic acid, heptanoic acid, octanoic acid, Nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, heptadecanoic acid, stearic acid, nonadecanoic acid, icosanoic acid, eicosenoic acid, elaidic acid, linoleic acid, ricinoleic acid, etc. It is done. A part of carboxyl groups of the carboxylic acid may form a salt with a metal ion (for the metal ion, two or more kinds of metal ions may be contained).

  The carboxylic acid may be a compound containing a functional group other than a carboxyl group, such as an amino group, a hydroxyl group, an alkoxy group, a carbonyl group, an ester group, or a mercapto group. In this case, the number of carboxyl groups is preferably equal to or greater than the number of functional groups other than carboxyl groups. Moreover, the said carboxylic acid may be used independently, respectively and may use 2 or more types together. In addition, the boiling point at normal temperature is preferably 300 ° C. or lower, more preferably 250 ° C. or lower.

  The amine content in the metal colloid dispersion is preferably 0.5% by mass to 30% by mass. If the amine content is 0.5% by mass or more, the storage stability of the resulting metal colloidal dispersion tends to be improved, and if it is 30% by mass or less, a film formed using the metal colloidal dispersion. The conductivity tends to be good. The more preferable content of the amine is 0.5% by mass to 20% by mass, and the more preferable content is 1% by mass to 10% by mass.

  Moreover, it is preferable that content of carboxylic acid in a metal colloid dispersion liquid is 0.1 mass%-10 mass%. If the content of the carboxylic acid is 0.1% by mass or more, the storage stability of the resulting metal colloidal dispersion tends to be better than that in the case of containing no carboxylic acid, and if it is 20% by mass or less. The metal film formed using the metal colloid dispersion tends to have good conductivity. The more preferable content of the organic substance is 0.5% by mass to 20% by mass, and the more preferable content is 1% by mass to 10% by mass.

  The composition ratio (mass) of amine and carboxylic acid can be arbitrarily selected within the range of 1/99 to 99/1, preferably 10/90 to 90/10, and more preferably 20 / 80-80 / 20. In addition, as amine or carboxylic acid, you may use multiple types of amine or carboxylic acid, respectively.

(1-3) Dispersion medium Although the dispersion medium contained in the metal colloid dispersion liquid of this embodiment is a "dispersion medium containing a photocurable organic compound", it should contain substantially only a photocurable organic compound. Is preferred. This “photo-curable organic compound” refers to an organic compound that is cured by irradiation with electromagnetic waves such as ultraviolet light and / or blue light, and is a concept including a conventional photosensitive organic compound. Examples thereof include a curable monomer and / or a photocurable resin.

  Examples of the photocurable monomer and the photocurable resin include at least one or two or more ultraviolet-polymerizable (crosslinkable) carbon-carbon double bonds (for example, ethylenically unsaturated double bonds) in the molecule. Examples thereof include a monofunctional or polyfunctional ultraviolet curable organic compound that can be formed into a three-dimensional network. These compounds can also be used individually by 1 type, and can also be used in combination of 2 or more type.

  Especially, as a photocurable organic compound, it is preferable that it is an ultraviolet curable monomer (acrylate compound or methacrylate compound) which has an acryloyl group or a methacryloyl group. As described above, since the ultraviolet curable monomer has a low viscosity, the ink jet discharge property of the metal colloid dispersion liquid of the present embodiment is improved, and the metal colloid dispersion liquid containing the ultraviolet curable monomer is used as a basis. When coated on the material, a film is formed in a state where the metal particles are well dispersed, and the carbon-carbon double bonds in the molecule are polymerized by ultraviolet rays to form a three-dimensional network. This is because a film having excellent adhesion can be obtained.

  Examples of monofunctional compounds such as acrylate compounds or methacrylate compounds include dicyclopentenyloxyethyl acrylate, allyl acrylate, 2-phenoxyethyl acrylate, benzyl acrylate, butoxyethyl acrylate, butoxyethylene glycol acrylate, cyclohexyl acrylate, and dicyclopentanyl. Acrylate, 2-ethylhexyl acrylate, glycerol acrylate, glycidyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, isobornyl acrylate, isooctyl acrylate, isostearyl acrylate, lauryl acrylate, 2-methoxy acrylate, methoxyethylene glycol acrylate , Phenoxyethyl acrylic , Stearyl acrylate, tetrahydrofurfuryl acrylate, ethoxylated o-phenylphenol acrylate, dicyclopentenyl acrylate, 2- (2-vinyloxyethoxy) ethyl acrylate, phenoxy polyethylene glycol acrylate, 4-hydroxybutyl acrylate, cyclic tri Examples include methylolpropane formal acrylate, 3,3,5 trimethylcyclohexane acrylate, and compounds obtained by replacing the acrylate (or acrylic acid) with methacrylate (or methacrylic acid).

  Examples of the polyfunctional compound having two or more functional groups with an acrylate compound or a methacrylate compound include 1,3-butylene diacrylate, neopentyl glycol diacrylate, dipropylene glycol diacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, 1,9-nonanediol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, 1,3-propanediol diacrylate, 1,4-cyclohexane Diol diacrylate, 2,2-dimethylolpropane diacrylate, glycerol diacrylate, tripropylene glycol diacrylate, pentaerythritol triacrylate, Intererythritol tetraacrylate, glycerol triacrylate, ethylene oxide modified pentaerythritol tetraacrylate, dioxane glycol diacrylate, propylene oxide modified pentaerythritol triacrylate, triethylene glycol diacrylate, polyoxypropyltrimethylolpropane triacrylate, butylene glycol diacrylate, Tricyclodecane dimethanol diacrylate, 1,2,4-butanetriol triacrylate, 2,2,4-trimethyl-1,3-pentanediol diacrylate, trimethylolpropane triacrylate, 1,10-decanediol diacrylate , Polypropylene glycol diacrylate, neopentyl hydroxypivalate Recall ester diacrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, compound was replaced with methacrylate dipentaerythritol hexaacrylate and the acrylate.

  The viscosity of the dispersion medium used in the present embodiment may be appropriately selected according to the desired viscosity of the metal colloidal dispersion, and is, for example, 1 mPa · s to 100 mPa · s, and further 3 mPa · s to 50 mPa · s. It is preferable from the viewpoint of handleability.

  The content of the dispersion medium in the metal colloid dispersion may be adjusted according to desired properties such as viscosity, and the content of the dispersion medium in the metal colloid dispersion is 15% by mass to 99.9% by mass. Is preferred. If the content of the dispersion medium is 15% by mass or more, the metal particles can be dispersed, and if it is 99% by mass or less, the effect of adding the metal particles can be obtained. The more preferable content of the dispersion medium is 40% by mass to 99.5% by mass, and the more preferable content is 60% by mass to 99% by mass.

(1-4) Other components In addition to the above components, the metal colloid dispersion liquid of the present embodiment is provided with functions such as adhesion, drying properties, and printability within a range not impairing the effects of the present invention. For this purpose, for example, an optional component such as an oligomer component, a resin component, a surfactant, a thickener, or a surface tension adjusting agent serving as a binder may be added. Such optional components are not particularly limited.

  Examples of the resin component include aromatic polyesters represented by polyethylene terephthalate obtained by polycondensation of carboxylic acid such as terephthalic acid and alcohol such as ethylene glycol, polylactic acid resin, hydroxycarboxylic acid polycondensate, Polycondensation of polycyclic polycondensates of aliphatic polyhydric alcohols and aliphatic carboxylic acids, such as ring-opening polymerization products of lactones such as caprolactone, polybutylene succinate, polybutylene adipate, polybutylene succinate adipate, etc. Polyester resins such as aliphatic polyesters obtained, all free isocyanate groups are known blocking agents, for example, oximes such as 2-butanone oxime and acetone oxime, lactams such as ε-caprolactam, ethyl acetoacetate, malon Active hydrogenation of ethyl acid Polyurethane resins, polyacrylate resins, polyacrylamide resins, polyether resins, melamine resins having a block isocyanate blocked with a product, urethane group, urea group, burette group, allophanate group, isocyanurate group in the skeleton Or a terpene-type resin etc. can be mentioned, These may be used independently, respectively and may use 2 or more types together.

  As the thickener, for example, clay minerals such as clay, bentonite or hectorite, for example, polyester emulsion resin, acrylic emulsion resin, polyurethane emulsion resin or emulsion such as blocked isocyanate, methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, Examples thereof include cellulose derivatives such as hydroxypropylcellulose and hydroxypropylmethylcellulose, polysaccharides such as xanthan gum and guar gum, and these may be used alone or in combination of two or more.

  You may add surfactant which consists of organic substance which is not contained in the said organic substance. In a multi-component solvent-based metal colloidal dispersion, roughness of the coating surface and uneven solid content are likely to occur due to differences in volatilization rate during drying. By adding a surfactant to the metal colloid dispersion liquid of this embodiment, a metal colloid dispersion liquid capable of suppressing these disadvantages and forming a uniform conductive film can be obtained.

  The surfactant that can be used in the present embodiment is not particularly limited, and any of an anionic surfactant, a cationic surfactant, and a nonionic surfactant can be used, for example, an alkylbenzene sulfonate. A quaternary ammonium salt etc. are mentioned. Since the effect can be obtained with a small addition amount, a fluorosurfactant is preferable.

  Furthermore, you may add the photosensitizer and / or polymerization inhibitor which consist of the organic substance which is not contained in the said organic substance to the metal colloid dispersion liquid of this embodiment. By adding a photosensitizer, the curing time can be shortened, and by adding a polymerization inhibitor, the storage stability of an unused metal colloidal dispersion can be enhanced.

  Examples of the photosensitizer include sulfur such as benzoin and derivatives thereof, benzoin ethers such as benzoin acrylic ether, benzyl and derivatives thereof, aromatic diazonium salt, anthraquinone and derivatives thereof, acetophenone and derivatives thereof, and diphenyl disulfide. Examples thereof include compounds, benzophenone and derivatives thereof, and any conventionally known photosensitizer can be used as long as the effects of the present invention are not impaired. Examples of the polymerization inhibitor include ion trapping agents such as crown ethers and cryptate, and hydroquinone and methoxyhydroquinone, and any conventionally known polymerization inhibitors can be used as long as the effects of the present invention are not impaired. . Usually, the addition amount of the photosensitizer or polymerization inhibitor may be appropriately selected depending on the type of the photosensitizer and the use of the metal colloid dispersion liquid. For example, other components of the metal colloid dispersion liquid of this embodiment are used. The total mass is preferably 0.05% by mass to 5% by mass.

(2) Method for Producing Metal Colloid Dispersion To produce the metal colloid dispersion of this embodiment, first, (2-1) preparing metal particles (metal colloid particles) coated with an organic substance as a dispersant. Then, (2-2) the metal colloid dispersion liquid of this embodiment can be obtained by adding and mixing the dispersion medium of the present invention to the metal particles.

(2-1) Method for Preparing Metal Particles Coated with Organic Substance (Amine and Carboxylic Acid) as Dispersant The method for preparing metal particles coated with organic substance as a dispersant of the present embodiment is not particularly limited. However, for example, a method of preparing a dispersion containing metal particles and then washing the dispersion can be used. As a step of preparing a dispersion containing metal particles, for example, a metal salt (or metal ion) dissolved in a solvent may be reduced as described below, and the reduction procedure is based on a chemical reduction method. A procedure may be adopted.

  That is, the metal particles coated with an organic substance as a dispersant as described above are a metal salt of a metal constituting the metal particles, an organic substance as a dispersant, and a solvent (basically an organic system such as toluene. , Which may contain water), and a raw material liquid containing a component (a part of the components may be dispersed without being dissolved). By this reduction, metal colloidal particles in which an organic substance as a dispersant covers at least a part of the surface of the metal particles are obtained, and when this is added to the dispersion medium in a step described later, the desired metal colloid dispersion liquid of this embodiment is obtained. can get.

  As a starting material for obtaining metal particles coated with an organic substance as a dispersant, various known metal salts or hydrates thereof can be used. For example, silver nitrate, silver sulfate, silver chloride, silver oxide, Silver salts such as silver oxalate, silver acetate, silver nitrite, silver chlorate and silver sulfide; for example, gold salts such as chloroauric acid, potassium gold chloride and sodium gold chloride; for example, chloroplatinic acid, platinum chloride and platinum oxide Platinum salts such as potassium chloroplatinate; for example, palladium salts such as palladium nitrate, palladium acetate, palladium chloride, palladium oxide, palladium sulfate, etc., but can be dissolved in a suitable dispersion medium and can be reduced. If it is a thing, it will not specifically limit. These may be used alone or in combination.

  The method for reducing these metal salts in the raw material liquid is not particularly limited, and examples thereof include a method using a reducing agent, a method of irradiating light such as ultraviolet rays, electron beams, ultrasonic waves, or thermal energy. Among these, a method using a reducing agent is preferable from the viewpoint of easy operation.

  Examples of the reducing agent include amine compounds such as dimethylaminoethanol, methyldiethanolamine, triethanolamine, phenidone, and hydrazine; for example, hydrogen compounds such as sodium borohydride, hydrogen iodide, and hydrogen gas; for example, carbon monoxide. Oxides such as sulfurous acid; for example, ferrous sulfate, iron oxide, iron fumaroleate, iron lactate, iron oxalate, iron sulfide, tin acetate, tin chloride, tin diphosphate, tin oxalate, tin oxide, sulfuric acid Low valent metal salts such as tin; for example, sugars such as ethylene glycol, glycerin, formaldehyde, hydroquinone, pyrogallol, tannin, tannic acid, salicylic acid, D-glucose, etc. There is no particular limitation as long as it can be reduced. When the reducing agent is used, light and / or heat may be added to promote the reduction reaction. In addition, when an oxalate such as silver oxalate is used as a starting material, metal ions are reduced only by heating without using a reducing agent.

  As a specific method for preparing metal particles coated with an organic substance as a dispersant using the metal salt, an organic substance as a dispersant, a solvent, and a reducing agent, for example, the metal salt is converted into an organic solvent (for example, toluene). Etc.) to prepare a metal salt solution, add an organic substance as a dispersant to the metal salt solution, and then gradually drop the solution in which the reducing agent is dissolved.

  In addition to the metal particles, the dispersion containing the metal particles coated with the organic substance as the dispersant obtained as described above contains a metal salt counter ion, a reducing agent residue and a dispersant. In addition, the concentration of components other than the metal particles in the entire liquid tends to be high. In the liquid in such a state, the metal particles easily precipitate due to the interaction between the metal particles and the impurities. Alternatively, even if precipitation does not occur, the conductivity of the metal salt may deteriorate if the counter ion of the metal salt, the residue of the reducing agent, or an excessive amount of dispersant remaining in the amount necessary for dispersion remains. Therefore, by washing the solution containing the metal particles to remove excess residues, the metal particles coated with an organic substance as a dispersant can be reliably obtained.

  As the washing method, for example, a dispersion containing metal particles coated with an organic substance as a dispersant is allowed to stand for a certain period of time, and the resulting supernatant is removed, and then alcohol (methanol or the like) is added and stirred again. A method of repeating the step of removing the supernatant liquid generated by standing still for a certain period of time, a method of performing centrifugation instead of the above-mentioned standing, a method of desalting with an ultrafiltration device, an ion exchange device, etc. Etc. Heating or distillation may be performed as necessary to remove low boiling point compounds. By removing the organic solvent by such washing, it is possible to obtain metal particles coated with an organic substance as a dispersant of the present embodiment.

(2-2) Method for Producing Metal Colloid Dispersion The metal colloid dispersion of the present embodiment is described in the above embodiment with the metal particles coated with the organic substance as the dispersant obtained in (2-1) above. The obtained dispersion medium (dispersion medium comprising a photocurable organic compound) is mixed.

  The mixing method of the metal particles and the dispersion medium is not particularly limited, and can be performed by a conventionally known method using a stirrer or a stirrer. You may stir with things like a spatula, or may apply the ultrasonic homogenizer of a suitable output.

  When obtaining a metal colloid dispersion liquid containing a plurality of metals, the production method is not particularly limited. For example, when producing a metal colloid dispersion liquid composed of silver and other metals, the above (2-1) In the preparation of metal particles coated with an organic substance as a dispersant in the above, a dispersion containing silver particles and a dispersion containing other metal particles may be produced separately and then mixed, and a silver ion solution and Other metal ion solutions may be mixed and then reduced.

(3) Coating (Base Material with Film) and Method for Producing the Same Using the metal colloid dispersion liquid of this embodiment, the metal colloid dispersion liquid coating step for coating the metal colloid dispersion liquid on the base material, and the coating on the base material The metal colloid dispersion (that is, the coating film) is irradiated with an electromagnetic wave such as ultraviolet light and / or blue light using, for example, a UV irradiation device, and is photocured, and a substrate, The board | substrate with a conductive film containing the conductive film formed in at least one part of the surface of the said base material can be manufactured.

  By curing the coating film, it is possible to obtain a conductive film having high conductivity and excellent metallic luster. In order to raise electroconductivity, a heating process can also be included suitably, and a heating process may be implemented before and after a light irradiation process. In the heating step, for example, the coating film or the conductive film can be heated and baked at a temperature of 300 ° C. or lower.

  As a result of intensive studies, the inventor of the present invention described above as the metal colloid dispersion in the metal colloid dispersion application step has excellent adhesion to the substrate. It has been found that a conductive film having the above can be obtained more reliably.

  Here, in the “metal colloid dispersion application step of applying a metal colloid dispersion to a substrate” in the present embodiment, “application to a substrate” is linear even when the metal colloid dispersion is applied to a surface. It is a concept including the case of applying (drawing). The shape of the coating film made of the metal colloid dispersion before being applied and fired by heating can be made into a desired shape. Therefore, the conductive film of the present embodiment after baking by heating is a concept including both a planar conductive film and a linear conductive film, and these planar conductive film and linear conductive film. The coating may be continuous or discontinuous, and may include a continuous portion and a discontinuous portion.

  The substrate that can be used in the present embodiment is not particularly limited as long as it has at least one main surface that can be coated with a metal colloid dispersion and baked by heating to be mounted with a conductive coating. Although it is not, it is preferable that it is a base material excellent in heat resistance.

  As a material constituting such a base material, for example, polyamide (PA), polyimide (PI), polyamideimide (PAI), polyetherimide (PEI), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), Examples thereof include polyester such as polyethylene naphthalate (PEN), polycarbonate (PC), polyethersulfone (PES), vinyl resin, fluororesin, liquid crystal polymer, ceramics, glass, and metal. Further, the substrate may have various shapes such as a plate shape or a strip shape, and may be rigid or flexible. The thickness of the substrate can also be selected as appropriate. In order to improve adhesiveness or adhesion, or for other purposes, a substrate on which a surface layer is formed or a substrate that has been subjected to a surface treatment such as a hydrophilic treatment may be used.

  Various methods can be used in the step of applying the metal colloid dispersion to the substrate. For example, as described above, for example, dipping, screen printing, spraying, bar coating, spin coating, ink jet , A dispenser type, a brush application method, a casting method, a flexo method, a gravure method, a syringe method, and the like. Especially, since the metal colloid dispersion liquid of this embodiment is excellent in inkjet discharge property as mentioned above, it is preferable to use an inkjet type.

  Next, the coating film obtained after coating as described above is photocured by irradiating electromagnetic waves such as ultraviolet light and / or blue light to obtain a conductive film. In order to irradiate electromagnetic waves such as ultraviolet light and / or blue light, a light source (UV irradiation device or visible light irradiation device) capable of irradiating an electromagnetic wave having a wavelength capable of reacting with a photocurable organic compound may be used. Conventionally known light sources such as an arc lamp, a mercury vapor arc lamp, a high-pressure mercury lamp, and a xenon lamp can be used.

  In the heating step that may be performed before or after the light irradiation step in order to increase the conductivity, the substrate is baked by heating to a temperature of 300 ° C. or less, for example, within a range that does not damage the substrate. A conductive film having a form (a substrate with a conductive film) can be obtained. In this embodiment, as described above, since the metal colloid dispersion liquid of this embodiment is used, a conductive film having excellent adhesion to the substrate can be obtained more reliably.

  In this embodiment, when the metal colloid dispersion liquid contains a binder component, the binder component is also sintered from the viewpoint of improving the strength of the conductive film and improving the adhesive strength with the substrate. The main purpose of the binder component is to adjust the viscosity of the metal colloidal dispersion for application to various printing methods, and the binder condition may be controlled to remove all the binder component.

  The method for performing the firing is not particularly limited. For example, the temperature of the metal colloid dispersion liquid applied or drawn on the substrate using a conventionally known gear oven or the like is, for example, 300 ° C. or less. A conductive film can be formed by baking. The lower limit of the calcination temperature is not necessarily limited, and is preferably a temperature at which a conductive film can be formed on the base material, and is a temperature within a range that does not impair the effects of the present invention (the effects of the present invention). A part of the binder component may remain as long as it is not impaired, but it is desirable that all of the binder component is desirably removed.)

  According to the metal colloid dispersion liquid of this embodiment, a conductive film that exhibits high conductivity can be formed even by a low-temperature heat treatment at, for example, about 150 ° C., so that it is conductive even on a relatively heat-sensitive substrate. A film can be formed. The firing time is not particularly limited, and may be any firing time that can form a conductive film on the substrate according to the firing temperature.

  In this embodiment, in order to further improve the adhesion between the substrate and the conductive film, the substrate may be subjected to a surface treatment. Examples of the surface treatment method include a method of performing dry treatment such as corona treatment, plasma treatment, UV treatment, and electron beam treatment, and a method of previously providing a primer layer and a conductive paste receiving layer on a substrate.

  Thus, the electroconductive film (base material with an electroconductive film) of this embodiment can be obtained. Thus, the thickness of the conductive film of this embodiment obtained is about 0.1 micrometer-5 micrometers, for example, More preferably, it is 0.1 micrometer-1 micrometer. If the metal colloid dispersion liquid of this embodiment is used, a conductive film having sufficient conductivity can be obtained even if the thickness is about 0.1 μm to 5 μm. In addition, the volume resistance value of the conductive film of this embodiment is 15 μΩ · cm or less.

In addition, the thickness t of the conductive film of this embodiment can be calculated | required, for example using a following formula (The thickness t of a conductive film is a laser microscope (for example, Keyence laser microscope VK-9510). It is also possible to measure.)
Formula: t = m / (d × M × w)
m: Weight of the conductive film (measured with an electronic balance the weight of the conductive film formed on the slide glass)
d: Conductive film density (g / cm ³ ) (10.5 g / cm ^{3 in} the case of silver)
M: Conductive film length (cm) (Measured length of conductive film formed on slide glass on a scale equivalent to JIS class 1)
w: Conductive film width (cm) (Measured width of the conductive film formed on the slide glass on a scale equivalent to JIS class 1)

  As mentioned above, although typical embodiment of this invention was described, this invention is not limited only to these. For example, in the above-described embodiment, the metal colloid dispersion liquid using metal particles as the inorganic component has been described. For example, tin-doped indium oxide having excellent conductivity, thermal conductivity, dielectric property, ion conductivity, alumina, Inorganic particles such as barium titanate and iron iron phosphate can also be used.

Hereinafter, the production method of the metal colloid dispersion of the present invention and the conductive coating of the present invention (substrate with a conductive coating) will be further described with reference to examples and comparative examples. The present invention is not limited to these examples. It is not limited. Each compound shown in Table 1 below was used.

Example 1
200 mL of toluene and 15 g of amine (hexylamine) were mixed and sufficiently stirred with a magnetic stirrer. Here, 10 g of silver nitrate was added while stirring, and after the silver nitrate was dissolved, a total of 15 g of carboxylic acid (5 g of oleic acid and 10 g of hexanoic acid were added in sequence) to obtain a toluene solution of silver nitrate. To this toluene solution of silver nitrate, 0.02 g / mL aqueous sodium borohydride solution prepared by adding 1 g of sodium borohydride to 50 mL of ion-exchanged water was dropped, and silver fine particles having an average particle size shown in Table 2 were added. A dispersion containing was obtained. The particle size of the silver fine particles was measured by the method described above.

  After stirring the dispersion containing silver particles for 1 hour, 200 mL of methanol was added to aggregate and settle silver fine particles. Furthermore, after the silver fine particles were completely settled by centrifugation, the supernatant toluene and methanol were removed by decantation. Toluene is further added to the remaining sediment to disperse the silver fine particles, methanol is added again, and the above operation is repeated. Finally, toluene and methanol are removed, excess organic matter is removed, and about 6 g of silver fine particles are removed. Got. 45 g of lauryl acrylate as a dispersion medium was added to 5 g of the silver fine particles thus obtained, and mixed by stirring to obtain a silver colloid dispersion liquid 1 of the present invention.

[Evaluation test]
(1) Viscosity The viscosity of the silver colloid dispersion liquid 1 obtained as described above was measured by using the vibration viscometer as described above (measurement temperature: 25 ° C.) as an index of ink jetting properties. The results are shown in Table 2.
(2) Dispersibility Further, the dispersibility of the silver colloid dispersion liquid 1 is evaluated by allowing the silver colloid dispersion liquid 1 to stand in a container and visually observing the presence or absence of precipitation and the state of the supernatant after 24 hours. did. The case where almost no sediment was observed at the bottom of the container was evaluated as “1”, and the case where any sediment was observed was evaluated as “2”. The results are shown in Table 2.

<< Examples 2 to 40 >>
Silver colloid dispersions 2 to 40 were obtained in the same manner as in Example 1 except that the amine, carboxylic acid and dispersion medium shown in Table 2 or 3 were used, and the same evaluation test as in Example 1 was performed. The results are shown in Table 2 or Table 3.

≪Comparative example 1≫
Example 5 Silver powder (silver powder FHD manufactured by Mitsui Mining & Smelting Co., Ltd.) as a silver particle and 45 g of lauryl acrylate as a dispersion medium are stirred and mixed with a magnetic stirrer to obtain a comparative silver colloid dispersion 1 The same evaluation test as 1 was performed. The results are shown in Table 4.

≪Comparative example 2≫
A comparative silver colloid dispersion 2 was obtained in the same manner as in Comparative Example 1 except that dipropylene glycol diacrylate was used as the dispersion medium, and the same evaluation test as in Example 1 was performed. The results are shown in Table 4.

«Comparative Example 3»
A comparative silver colloidal dispersion 3 was obtained in the same manner as in Comparative Example 1 except that silver powder (silver powder SPN10J manufactured by Mitsui Metal Mining Co., Ltd.) was used as the silver particles, and the same evaluation test as in Example 1 was performed. The results are shown in Table 4.

<< Comparative Example 4 >>
A comparative silver colloid dispersion 4 was obtained in the same manner as in Comparative Example 3 except that dipropylene glycol diacrylate was used as the dispersion medium, and the same evaluation test as in Example 1 was performed. The results are shown in Table 4.

<< Comparative Example 5 >>
A comparative silver colloid dispersion 5 was obtained in the same manner as in Comparative Example 1 except that silver powder (AG-025 manufactured by Shoei Chemical Industry Co., Ltd.) was used as the silver particles, and the same evaluation test as in Example 1 was performed. . The results are shown in Table 4.

<< Comparative Example 6 >>
A comparative silver colloidal dispersion 6 was obtained in the same manner as in Comparative Example 5 except that dipropylene glycol diacrylate was used as the dispersion medium, and the same evaluation test as in Example 1 was performed. The results are shown in Table 4.

<< Comparative Example 7 >>
Dispersant sodium citrate dihydrate 6.82 g and reducing agent ferrous sulfate heptahydrate 5.82 g were dissolved in 100 mL of ion-exchanged water. While stirring the resulting solution with a magnetic stirrer at room temperature, 100 mL of an aqueous solution containing 2.89 g of chloroauric acid tetrahydrate was added dropwise to prepare a colloidal gold solution. The obtained colloidal gold solution was filtered using an ultrafiltration membrane to remove impurity ions. 9 g of 4-hydroxybutyl acrylate as a dispersion medium was added to 1 g of silver solid content taken out by centrifuging the gold colloid liquid, and a comparative gold colloid dispersion liquid 7 was obtained by stirring and mixing. An evaluation test was conducted. The results are shown in Table 4.

«Comparative Example 8»
A comparative gold colloid dispersion 8 was obtained in the same manner as in Comparative Example 7 except that dipropylene glycol diacrylate was used as the dispersion medium, and the same evaluation test as in Example 1 was performed. The results are shown in Table 4.

<< Comparative Example 9 >>
1.97 g of silver nitrate was dissolved in 100 mL of ion exchange water to prepare an aqueous silver nitrate solution. Next, while adding 0.8 g of gallic acid to 100 mL of ion-exchanged water and stirring, 100 mL of the silver nitrate aqueous solution prepared previously and 10 mL of 1N NaOH aqueous solution for pH adjustment were added thereto and stirred for 1 hour. As a result, an aqueous silver colloid solution was obtained. This was filtered with an ultrafiltration membrane to remove impurity ions. Example 1 A silver colloid dispersion 9 for comparison was obtained by adding 9 g of 4-hydroxybutyl acrylate, which is a dispersion medium, to 1 g of silver solid content extracted by centrifuging this silver colloid aqueous solution. The same evaluation test was conducted. The results are shown in Table 4.

<< Comparative Examples 10-11 >>
A comparative silver colloidal dispersion 10 or 11 was obtained in the same manner as in Comparative Example 9 except that dipropylene glycol diacrylate or lauryl acrylate was used as the dispersion medium, and the same evaluation test as in Example 1 was performed. The results are shown in Table 4.

<< Comparative Example 12 >>
To an aqueous solution in which 17 g of trisodium citrate dihydrate and 0.7 g of tannic acid were dissolved in 280 mL of water, 3 mL of 10 N NaOH aqueous solution was added. 3 mL of an aqueous solution containing 1.97 g of silver nitrate was added to the obtained solution while stirring, and stirring was performed for 2 hours to obtain a silver colloid aqueous solution. The obtained silver colloid solution was desalted and then centrifuged to obtain a silver solid. 9 g of 4-hydroxybutyl acrylate as a dispersion medium was added to 1 g of this silver solid content, and a comparative silver colloid dispersion 12 was obtained by stirring and mixing, and the same evaluation test as in Example 1 was performed. The results are shown in Table 4.

<< Comparative Examples 13-14 >>
A comparative silver colloidal dispersion 13 or 14 was obtained in the same manner as in Comparative Example 12 except that dipropylene glycol diacrylate or lauryl acrylate was used as the dispersion medium, and the same evaluation test as in Example 1 was performed. The results are shown in Table 4.

As is apparent from the results shown in Tables 2 to 4, it is understood that the colloidal dispersion liquid of the present invention is excellent in dispersibility and inkjet discharge performance in a well-balanced manner.

Claims (7)

An inorganic component containing metal particles;
An organic substance containing at least an amine covering at least a part of the surface of the metal particles;
A dispersion medium containing a photocurable organic compound;
Including
A colloidal dispersion characterized by The photocurable organic compound is an ultraviolet curable monomer having an acryloyl group or a methacryloyl group,
The colloidal dispersion according to claim 1. The average particle diameter of the metal particles is 0.7 nm to 200 nm,
The colloid dispersion liquid according to claim 1 or 2, wherein Having a viscosity of 1 mPa · s to 100 mPa · s,
The colloidal dispersion according to any one of claims 1 to 3. Furthermore, including carboxylic acid as an organic substance,
The colloidal dispersion according to any one of claims 1 to 4. The number of carbon atoms of the amine is 3 or more per amino group;
The colloid dispersion liquid according to any one of claims 1 to 5. The ink used for the inkjet system, the gravure system, or the flexo system containing the colloid dispersion liquid in any one of Claims 1-6.