WO2018150697A1 - Conductive paste for gravure offset printing, method for forming conductive pattern, and method for manufacturing conductive substrate - Google Patents

Conductive paste for gravure offset printing, method for forming conductive pattern, and method for manufacturing conductive substrate Download PDF

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Publication number
WO2018150697A1
WO2018150697A1 PCT/JP2017/044157 JP2017044157W WO2018150697A1 WO 2018150697 A1 WO2018150697 A1 WO 2018150697A1 JP 2017044157 W JP2017044157 W JP 2017044157W WO 2018150697 A1 WO2018150697 A1 WO 2018150697A1
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Prior art keywords
conductive paste
offset printing
conductive
gravure offset
fine particles
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PCT/JP2017/044157
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French (fr)
Japanese (ja)
Inventor
祐樹 新谷
外村　卓也
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バンドー化学株式会社
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Priority to JP2017565327A priority Critical patent/JP6348241B1/en
Publication of WO2018150697A1 publication Critical patent/WO2018150697A1/en

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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D11/00—Inks
    • C09D11/02—Printing inks
    • C09D11/03—Printing inks characterised by features other than the chemical nature of the binder
    • C09D11/037—Printing inks characterised by features other than the chemical nature of the binder characterised by the pigment
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D11/00—Inks
    • C09D11/52—Electrically conductive inks
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/20—Conductive material dispersed in non-conductive organic material
    • H01B1/22—Conductive material dispersed in non-conductive organic material the conductive material comprising metals or alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B13/00—Apparatus or processes specially adapted for manufacturing conductors or cables
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/10—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern
    • H05K3/12—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern using thick film techniques, e.g. printing techniques to apply the conductive material or similar techniques for applying conductive paste or ink patterns

Definitions

  • the present invention relates to a conductive paste for gravure offset printing, a method for forming a conductive pattern using the conductive paste for gravure offset printing, and a method for manufacturing a conductive substrate using the method for forming the conductive pattern.
  • Patent Document 1 a conductive metal particle (A), an organic compound (B) that is solid at 50 ° C. and has a boiling point at normal pressure exceeding 300 ° C., and a liquid that is liquid at 50 ° C. and has a boiling point at normal pressure.
  • a conductive paste for bezel pattern printing by a gravure offset printing method containing (B) a non-volatile content of 1.0 to 3.0% in terms of mass with respect to the total of (A) to (D) And, in terms of the mass of the non-volatile content, the total use amount of the organic compound (B) and the organic compound (C) is R and the use amount of the conductive metal particles (A) is P. / P is set to 0.07 to 0.15 It discloses conductive paste.
  • Patent Document 2 discloses a method for producing a conductive film using a conductive copper paste that does not contain a thermosetting resin component or glass frit, and the conductive copper paste has an average particle diameter. Selected from the range of 2 ⁇ m to 10 ⁇ m, fine copper powder selected from the average particle size of 0.2 ⁇ m to 1.0 ⁇ m, a copper salt of a specific aliphatic monocarboxylic acid, a specific (dialkylamino ) Using the conductive copper paste containing a specific amount of alkylamine, a polymer binder having a thermal decomposition temperature in a specific range, and a first organic solvent having a specific functional group having a boiling point in a specific range, Production of a conductive film, characterized in that after applying a copper paste on a resin substrate, light irradiation is performed in a state where the residual amount of the first organic solvent is 0.1 to 5% by mass. A method is disclosed There.
  • gravure offset printing which is a kind of the intaglio printing method, is suitably used because it is suitable for fine line printing.
  • a conductive paste is filled in a recess formed on the surface of a gravure plate, the conductive paste is temporarily transferred to a blanket, and the conductive paste transferred to the blanket is transferred to an adherend.
  • the print pattern formed on the surface of the gravure plate is printed on the adherend. Therefore, the conductive paste for gravure offset printing has an appropriate viscosity so that it can be easily filled in the concave portion of the gravure plate, and the transfer from the gravure plate to the blanket and the transfer from the blanket to the adherend are good. In order to achieve this, it is required to have a degree of tackiness (tack) in a semisolid / semiliquid state.
  • Patent Document 1 The conductive paste described in Patent Document 1 is designed for printing a bezel pattern, and there is room for further study in order to cope with the thinning of the conductive pattern in recent years. Moreover, in the said patent document 2, it is not examined about the thinning of the conductive pattern formed by gravure offset printing.
  • the present invention has been made in view of the above problems, and has a sufficient conductivity and good adhesion to a substrate and can form a fine conductive pattern, a conductive paste for gravure offset printing, and a conductive material.
  • a method for forming a conductive pattern and a method for manufacturing a conductive substrate are provided.
  • the present inventors have added a water-soluble polymer to the conductive paste in order to thin the conductive pattern formed by the gravure offset printing method.
  • the present inventors have found that the adhesiveness in a semi-solid / semi-liquid state is improved and fine line printing is possible by gravure offset printing, and the present invention has been achieved.
  • the conductive paste for gravure offset printing of the present invention contains silver fine particles, an organic solvent, and a water-soluble polymer, and the average particle size of the silver fine particles is 1 ⁇ m or less.
  • the water-soluble polymer preferably contains a polymerizable compound having a cyclic structure.
  • the water-soluble polymer preferably contains polyvinyl pyrrolidone.
  • the content of the water-soluble polymer is preferably 3 to 8% by weight with respect to the entire conductive paste.
  • the organic solvent preferably contains a first organic solvent containing a hydroxyl group and having a boiling point of 200 ° C. or higher at normal pressure.
  • the organic solvent preferably contains 3.0 to 30% by weight of a second organic solvent having a blanket swelling ratio of 2.0% or less based on the entire conductive paste.
  • the method for forming a conductive pattern of the present invention uses a gravure offset printing method using a gravure plate, and the gravure plate has a recess filled with a conductive paste for gravure offset printing on the printing surface,
  • the width is 10 ⁇ m or less
  • the gravure offset printing conductive paste is the gravure offset printing conductive paste of the present invention.
  • the method for producing a conductive substrate of the present invention is characterized in that a conductive pattern is drawn on a substrate using the method for forming a conductive pattern of the present invention.
  • the conductive paste for gravure offset printing of the present invention has sufficient conductivity and good adhesion to a substrate, fine line printing by gravure offset printing is possible. Moreover, according to the method for forming a conductive pattern of the present invention, a conductive pattern having a line width of 10 ⁇ m or less can be formed, and even a conductive pattern having a line width of 3 ⁇ m or less is formed without disconnection. be able to. According to the method for manufacturing a conductive substrate of the present invention, a conductive substrate on which a precise conductive pattern is printed can be manufactured.
  • the conductive paste for gravure offset printing of the present invention contains silver fine particles, an organic solvent, and a water-soluble polymer, and the average particle size of the silver fine particles is 1 ⁇ m or less. Since the conductive paste for gravure offset printing of the present invention contains an organic solvent and a water-soluble polymer, it is difficult to dry and has a degree of adhesiveness in a semi-solid / semi-liquid state. Suitable for fine line printing.
  • the average particle diameter of the silver fine particles is 1 ⁇ m or less.
  • a fine conductive pattern having a line width of 3 ⁇ m or less can be formed using a gravure offset printing method.
  • the shape of the silver fine particles is not particularly limited as long as the effects of the present invention are not impaired.
  • coarse silver particles having an average particle diameter exceeding 1 ⁇ m are used, for example, when the width of the recess formed on the surface of the gravure plate is 3 ⁇ m, only a few silver particles can be filled. It is difficult to form a fine conductive pattern.
  • the particle diameter of the silver particles there may be a case where the silver particles cannot be filled at all in the 3 ⁇ m-wide recess.
  • the silver fine particles preferably have an average particle size that causes a melting point drop.
  • the gravure plate can be densely filled with a large number of silver fine particles, and the silver fine particles can be arranged so as to overlap each other, so that the silver fine particles are sintered (necking). It is easy to make.
  • the particle diameter is extremely small, the influence of one silver fine particle on the print quality can be further reduced.
  • the average particle diameter of the silver fine particles is 1 nm or more, the silver fine particles have good low-temperature sinterability, and the production cost of the silver fine particles can be suppressed, which is practical. Further, when the average particle size of the silver fine particles is 200 nm or less, the dispersibility of the silver fine particles hardly changes over time.
  • the more preferable lower limit of the average particle diameter of the silver fine particles is 2 nm, and the more preferable upper limit is 100 nm.
  • the silver fine particles may contain submicron-sized silver fine particles having an average particle diameter of more than 200 nm and 1 ⁇ m or less. When submicron-sized silver fine particles are used, the silver fine particles have a large particle diameter, so that the sinterability between the silver fine particles is slightly lowered, but sufficient thin line printing is possible.
  • the silver fine particles may contain nanometer-sized silver fine particles having an average particle diameter of 1 to 200 nm and submicron-sized silver fine particles having an average particle diameter of more than 200 nm and not more than 1 ⁇ m.
  • nanometer-sized silver fine particles and submicron-sized silver fine particles in combination, the nanometer-sized silver fine particles drop in melting point around the submicron-sized silver fine particles, so that only the submicron-sized silver fine particles are obtained. A better conductive path can be obtained than when it is used.
  • the particle diameter of the silver fine particles can be measured by a dynamic light scattering method, a small angle X-ray scattering method, or a wide angle X-ray diffraction method.
  • the “average particle diameter” refers to a dispersion median diameter.
  • the dispersion median diameter is calculated by obtaining a dispersed particle diameter by using a dynamic light scattering method (Dynamic Light Scattering) with a particle diameter reference as a volume reference.
  • a DLS measuring device for example, a particle size distribution measuring device (model number: LB-550) manufactured by Horiba, Ltd. can be used.
  • the synthesized silver fine particle dispersion is diluted 100 times with terpineol, and the solvent refractive index is measured as 1.383.
  • the weight ratio of the silver fine particles to the whole nonvolatile content of the conductive paste is preferably 90% by weight or more.
  • the non-volatile content refers to components other than organic solvents, in addition to silver fine particles, organic components that cover silver fine particles described later, water-soluble polymers contained in conductive paste, polymer dispersants, thickeners, etc. Is included.
  • the weight ratio of the silver fine particles is 90% by weight or more, a conductive pattern having a high silver content can be formed. Since the silver fine particles are excellent in chemical stability, by using silver fine particles as the main, it is possible to form a conductive pattern that is difficult to be oxidized and whose volume resistance value is difficult to decrease.
  • a metal whose ionization column is more noble than hydrogen that is, gold, copper, platinum, palladium, etc. Particles may be added.
  • the conductive paste for gravure offset printing of the present invention contains metal particles other than silver, the content ratio of the silver fine particles to the total metal particles including the silver fine particles and the metal particles other than silver is 90% by weight or more. Preferably there is.
  • an organic component adheres to at least a part of the surface of the silver fine particles.
  • the surface of the silver fine particles is more preferably coated with an organic component.
  • the said organic component comprises an inorganic colloid particle substantially with the said silver fine particle as what is called a dispersing agent.
  • the organic component includes trace organic substances contained in the silver fine particles as impurities from the beginning, trace organic substances adhering to the silver fine particles mixed in the manufacturing process described later, residual reducing agent that could not be removed in the cleaning process, residual dispersant, etc. As described above, it is a concept that does not include organic substances or the like adhered to silver fine particles.
  • the “trace amount” specifically means less than 1% by weight in the inorganic colloidal particles.
  • the organic component is an organic substance capable of covering silver fine particles to prevent aggregation of silver fine particles and forming inorganic colloidal particles, and contains an amine and a carboxylic acid from the viewpoint of dispersibility and conductivity. Is preferred.
  • these organic components when these organic components are chemically or physically bonded to the silver fine particles, it may be considered that they are changed to anions and cations, and ions and complexes derived from these organic components are also Contained in the ingredients.
  • the amine may be linear or branched, and may have a side chain.
  • N- (3-methoxypropyl) propane-1,3-diamine, 1,2-ethanediamine, 2-methoxyethylamine, 3-methoxypropylamine, 3-ethoxypropylamine, 1,4-butane Diamine diamine such as 1,5-pentanediamine, pentanolamine, aminoisobutanol, alkoxyamine or aminoalcohol, alkylamine such as propylamine, butylamine, pentylamine, hexylamine, hexylamine (linear alkylamine)
  • a cycloalkylamine such as cyclopentylamine and cyclohexylamine; a primary amine such as aniline and allylamine; a second amine such as dipropylamine, dibutylamine, piperidine, and hexamethyleneimine.
  • 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. Moreover, the said amine may be used independently and may use 2 or more types together.
  • the amine preferably has a boiling point at normal pressure of 300 ° C. or lower, and more preferably 250 ° C. or lower.
  • a carboxylic acid may be included in addition to the above amine.
  • the carboxyl group in one molecule of the carboxylic acid has a relatively high polarity and tends to cause an interaction due to a hydrogen bond, but a portion other than these functional groups has a relatively low polarity. Furthermore, the carboxyl group tends to exhibit acidic properties.
  • the compound which has at least 1 carboxyl group can be used widely, For example, formic acid, oxalic acid, acetic acid, hexanoic acid, acrylic acid, octylic acid, oleic acid etc. are mentioned.
  • a part of carboxyl groups of the carboxylic acid may form a salt with a metal ion.
  • 2 or more types 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.
  • the number of carboxyl groups is preferably equal to or greater than the number of functional groups other than carboxyl groups.
  • the said carboxylic acid may be used independently, respectively and may use 2 or more types together.
  • the carboxylic acid preferably has a boiling point at normal pressure of 300 ° C. or lower, and more preferably 250 ° C. or lower.
  • the amine and carboxylic acid form an amide group. Since the amide group also moderately adsorbs on the surface of the silver fine particles, the organic component may contain an amide group.
  • the content of the organic component in the inorganic colloid in the conductive paste for gravure offset printing of the present invention is preferably 0.5 to 50% by weight. If the organic component content is 0.5% by weight or more, the storage stability of the resulting conductive paste tends to be improved, and if it is 50% by weight or less, the conductivity of the conductive pattern tends to be good. . A more preferable content of the organic component is 1 to 30% by weight, and a more preferable content is 2 to 15% by weight.
  • the composition ratio (weight) of the amine and the carboxylic acid can be arbitrarily selected within the range of 1/99 to 99/1.
  • the composition ratio of the amine to the carboxylic acid is 20/80 to 98/2, and more preferably 30/70 to 97/3.
  • the conductive paste for gravure offset printing of the present invention contains an organic solvent as a dispersion medium for silver fine particles. Aggregation of silver fine particles can be suppressed by using an organic solvent as a dispersion medium. Moreover, since it generally has a high boiling point and is difficult to dry, it can be easily transferred to a blanket. In addition, since the surface tension is low, familiarity with silicone rubber generally used as a blanket is good. When water is used as the dispersion medium, silver fine particles may aggregate and clog the concave portions of the gravure plate. Further, water is not suitable as a dispersion medium for conductive paste used for gravure offset printing having a transfer process because of high surface tension, poor wettability to a blanket, low boiling point, and easy drying.
  • the organic solvent preferably contains a first organic solvent containing a hydroxyl group and having a boiling point of 200 ° C. or higher at normal pressure. Since the conductive paste for gravure offset printing of the present invention is suitably used for fine line printing with a line width of 10 ⁇ m or less, particularly 3 ⁇ m or less, it is preferable to use a solvent that is difficult to dry. When the boiling point of the first organic solvent at normal pressure is 200 ° C. or higher, the conductive paste can be prevented from being excessively dried on the gravure plate. In addition, when the first organic solvent contains a hydroxyl group, the dispersion of the silver fine particles becomes good, and the polarity of the organic solvent increases, so that the swelling of the blanket tends to be suppressed.
  • the first organic solvent examples include 2,4-diethyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, tripropylene glycol, It is preferable to use a diol solvent such as triethylene glycol, 1,2-hexanediol, 1.3 butylene glycol, 1,3-propanediol, dipropylene glycol, 2-butene-1,4-diol.
  • a diol solvent such as triethylene glycol, 1,2-hexanediol, 1.3 butylene glycol, 1,3-propanediol, dipropylene glycol, 2-butene-1,4-diol.
  • the content of the first organic solvent in the entire conductive paste is preferably 3 to 30% by weight.
  • a more preferred upper limit for the content of the first organic solvent is 25% by weight, and a more preferred upper limit is 20% by weight.
  • the organic solvent preferably contains 3.0 to 30% by weight of a second organic solvent having a blanket swelling rate of 2.0% or less.
  • the second organic solvent having a blanket swelling ratio of 2.0% or less is also referred to as a “low swelling organic solvent”.
  • the second organic solvent may also serve as the first organic solvent.
  • the blanket swelling ratio of the organic solvent is 2.0% or less, for example, it is possible to cope with the formation of a thin wire conductive pattern having a line width of 3 ⁇ m or less.
  • a more preferable blanket swelling ratio is 0.4% or less.
  • the content ratio of the second organic solvent to the entire conductive paste is 3.0% by weight or more, it is possible to impart appropriate coating properties (fluidity) to the conductive paste, For example, drying at the time of fine line printing with a line width of 3 ⁇ m or less can be suppressed.
  • the content By setting the content to 30% by weight or less, it is possible to prevent the spread during printing.
  • the more preferable upper limit of the content of the low swelling organic solvent is 25.0% by weight, and the more preferable upper limit is 20.0% by weight.
  • the outermost surface of a printing plate used for gravure offset printing is made of silicone rubber
  • the “blanket swelling ratio” in the present invention means a swelling ratio when silicone rubber is immersed in an organic solvent.
  • the blanket swelling rate is the same as the weight change rate of the blanket (silicone rubber) before and after the immersion when the blanket (silicone rubber) is immersed in an organic solvent.
  • a blanket (silicone rubber) is cut into a 1 cm square to obtain a test piece, and the test piece is immersed in an organic solvent under room temperature conditions (25 ° C. ⁇ 5 ° C.), taken out after 10 hours, and weight before and after immersion.
  • room temperature conditions 25 ° C. ⁇ 5 ° C.
  • the low-swelling organic solvent having a blanket swelling rate of 2.0% or less various solvents can be used as long as the effects of the present invention are not impaired.
  • the solvent which has a hydroxyl group as a functional group is preferable, for example, the polyhydric alcohol which has two or more hydroxyl groups, other monohydric alcohol solvents, etc. are mentioned.
  • a highly polar solvent such as a diol having a very low blanket swelling rate, drying of the fine line pattern on the blanket can be more effectively suppressed.
  • These solvents may be used alone or in combination of two or more.
  • Examples of the polyhydric alcohol having 2 to 3 hydroxyl groups include glycerin, 1,2,4-butanetriol, 1,2,6-hexanetriol, ethylene glycol, diethylene glycol, 1,2-butanediol, propylene Glycol, 2-methylpentane-2,4-diol and the like.
  • Examples of the monohydric alcohol include butyl triglycol, isobutyl diglycol, 2-butoxyethanol, 3-methoxy-3-methylbutanol, 2- (2-methoxyethoxy) ethanol, 2- (2-hexyloxyethoxy) ethanol Etc.
  • 2,4-diethyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, tripropylene Diol solvents such as glycol, triethylene glycol, 1,2-hexanediol, 1.3 butylene glycol, 1,3-propanediol, dipropylene glycol, and 2-butene-1,4-diol may be used.
  • the blanket swelling rate can be adjusted by adjusting the drying property.
  • a solvent having a high swelling ratio exceeding 2.0% may be mixed and used.
  • the number and combination of solvents to be mixed are not particularly limited.
  • Organic solvent with blanket swelling rate exceeding 2.0% examples include glycol ethers, glycol esters, terpene solvents, hydrocarbon solvents, alcohol solvents, and the like. These solvents may be used alone or in combination of two or more. If the concentration of the terpene solvent in the organic solvent is too high, the amount of solvent absorbed by the blanket increases, and drying tends to proceed on the blanket during transfer printing.Therefore, the diol solvent and the terpene solvent are balanced. It is preferable to mix.
  • organic solvent having a blanket swelling rate exceeding 2.0% include, for example, tripropylene glycol-n-butyl ether, butyl carbitol, diethylene glycol monomethyl ether, tripropylene glycol methyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol.
  • Examples include ether acetate.
  • the hydrocarbon solvent may contain an aliphatic hydrocarbon compound, may contain a cyclic hydrocarbon compound, or may contain an alicyclic hydrocarbon compound. .
  • aliphatic hydrocarbon compounds include saturated or unsaturated aliphatic compounds such as tetradecane, octadecane, heptamethylnonane, tetramethylpentadecane, hexane, heptane, octane, nonane, decane, tridecane, methylpentane, normal paraffin, and isoparaffin. There may be mentioned hydrocarbon compounds.
  • Examples of the cyclic hydrocarbon compound include toluene, xylene and the like.
  • Examples of the alicyclic hydrocarbon compound include limonene, dipentene, terpinene, terpinene (also referred to as terpinene), nesol, sinene, orange flavor, terpinolene, terpinolene (also referred to as terpinolene), ferrandrene, mentadiene, teleben, Examples thereof include dihydrocymene, moslen, isoterpinene, isoterpinene (also referred to as isoterpinene), clitomen, kautssin, cajeptene, oilimene, pinene, turpentine, menthane, pinane, terpene, and cyclohexane.
  • the alcohol solvent is a compound containing one or more hydroxyl groups in the molecular structure, and examples thereof include aliphatic alcohols, cyclic alcohols, and alicyclic alcohols. These alcohols may be used alone or in combination of two or more. Moreover, a part of hydroxyl group may be induced
  • aliphatic alcohol examples include heptanol, octanol (1-octanol, 2-octanol, 3-octanol, etc.), decanol (1-decanol, etc.), lauryl alcohol, tetradecyl alcohol, cetyl alcohol, 2-ethyl-1 -Saturated or unsaturated aliphatic alcohols having 6 to 30 carbon atoms such as hexanol, octadecyl alcohol, hexadecenol and oleyl alcohol.
  • Examples of the cyclic alcohol include cresol and eugenol.
  • alicyclic alcohol examples include cycloalkanols such as cyclohexanol, terpineol (including terpineol, ⁇ , ⁇ , ⁇ isomers, or any mixture thereof), and terpene alcohols such as dihydroterpineol (monoterpene alcohols). Etc.), dihydroterpineol, myrtenol, sobrerol, menthol, carveol, perillyl alcohol, pinocarveol, sobrerol, berbenol and the like.
  • the alicyclic alcohol may overlap with the terpene solvent.
  • the conductive paste for gravure offset printing of the present invention contains a water-soluble polymer.
  • a water-soluble polymer By containing a water-soluble polymer, the adsorption action to the blanket and adherend interface is enhanced, so that even if the conductive pattern has a line width of 3 ⁇ m or less, for example, without breaking, using the gravure offset printing method Can be formed.
  • water-soluble means one having a solubility of 1 g or more with respect to 1 L of water.
  • the water-soluble polymer is preferably a polymer that is soluble in both an organic solvent and water. Furthermore, the water-soluble polymer is required to have no adhesiveness to the substrate, transferability to the substrate, and difficulty in spreading the line on the blanket.
  • the adherend (base material) of the conductive paste is, for example, polyethylene terephthalate (PET), one having good adhesion to PET is preferable.
  • the water-soluble polymer preferably contains a polymerizable compound having a cyclic structure. Although solubility in organic solvents is limited, polyvinyl alcohol can also be used.
  • the cyclic structure is preferably ⁇ -lactam and preferably has a vinyl group. Especially, it is more preferable that the water-soluble polymer contains polyvinyl pyrrolidone.
  • Polyvinylpyrrolidone is a polymer represented by the following chemical formula (1).
  • n is a natural number.
  • Polyvinylpyrrolidone is highly soluble in highly polar polyhydric alcohols (especially diol solvents) and can be dissolved well in solvents such as esters and ketones. Can be dispersed. In particular, it dissolves well in a first organic solvent containing a hydroxyl group and having a boiling point of 200 ° C. or higher at normal pressure.
  • polyvinyl pyrrolidone is soluble in water, the adsorption action on the substrate interface can be remarkably enhanced. Furthermore, as a feature of gravure offset printing, a semi-solid / semi-liquid paste is transferred and printed on a blanket. Polyvinylpyrrolidone has a very high tack (adhesiveness) in a semi-solid / semi-liquid state. Therefore, it is very excellent in transferring from a blanket to a substrate. Therefore, the printability in thin line printing with a line width of, for example, 3 ⁇ m or less, which could not be printed with a conventional conductive paste, can be significantly improved.
  • the polyvinyl pyrrolidone preferably has an average molecular weight of 100,000 or less. When the average molecular weight is 100,000 or less, the viscosity of the conductive paste is not excessively increased, and transferability to a blanket or a substrate can be improved.
  • examples of such polyvinyl pyrrolidone include polyvinyl pyrrolidone K25 (average molecular weight: 25000), polyvinyl pyrrolidone K30 (average molecular weight: 40000) (both manufactured by Wako Pure Chemical Industries, Ltd.) and the like.
  • the average molecular weight is a weight average molecular weight and is measured by liquid chromatography.
  • LC-6AD pump For the measurement of the weight average molecular weight, LC-6AD pump, RID-10A RI detector, CLASS-LC10 Chromatopac data processor, and DGU-20A3 degasser manufactured by Shimadzu Corporation are used.
  • TSK-GEL G1000H, G2000H, and G2500H are used as columns, and the oven temperature is set to 40 ° C., and tetrahydrofuran (THF) is allowed to flow at a flow rate of 1.0 mL / min.
  • THF tetrahydrofuran
  • the content of the water-soluble polymer is preferably 3 to 8% by weight with respect to the entire conductive paste.
  • the content of the water-soluble polymer is less than 3% by weight, the adhesion to the adherend may be lowered.
  • the content of the water-soluble polymer exceeds 8% by weight, the volume resistance value of the conductive pattern formed by the conductive paste of the present invention may increase.
  • the upper limit with more preferable content of the said water-soluble polymer is 7 weight%.
  • conductive paste for gravure offset printing of the present invention in addition to the above components, functions such as appropriate viscosity, adhesion, drying property or printability according to the purpose of use within the range not impairing the effects of the present invention.
  • an optional component such as a polymer dispersant, an oligomer component, a surfactant, a thickener, or a surface tension adjuster may be added.
  • Such optional components are not particularly limited.
  • a commercially available polymer dispersant can be used as the polymer dispersant.
  • the commercially available polymer dispersing agent include Solsperse 11200, Solsperse 13940, Solsperse 16000, Solsperse 17000, Solsperse 18000, Solsperse 20000, Solsperse 24000, Solsperse 26000, Solsperse 27000, Solsperse 28000 (manufactured by Nippon Lubrizol) DISPERBYK-102, 110, 111, 170, 190.194N, 2015, 2090, 2096 (manufactured by Big Chemie Japan); EFKA-46, EFKA-47, EFKA-48, EFKA-49 (manufactured by EFKA Chemical); Polymer 100, Polymer 120, Polymer 150, Polymer 400, Polymer 401, Polymer 402, Polymer 403, Polymer 45 , Polymer 451, polymer 452, polymer 453 (manufactured by EFKA Chemical Co.); A
  • Solsperse 28000 examples include DA-375 and DA-1200. From the viewpoint of low temperature sinterability and dispersion stability, DISPER YK-102, Solsperse 11200, Solsperse 13940, Solsperse 16000, Solsperse 17000, Solsperse 18000, it is preferable to use Solsperse 28000 and the like.
  • the content of the polymer dispersant is preferably 0.1 to 15% by weight with respect to the entire conductive paste. If the content of the polymer dispersant is 0.1% by weight or more with respect to the entire conductive paste, the dispersion stability of the resulting conductive paste is improved, but if the content is too large, the dispersion stability is lowered. Will be. From such a viewpoint, the more preferable content of the polymer dispersant is 0.3 to 3% by weight, and the more preferable content is 0.5 to 2% by weight.
  • the thickener examples include clay minerals such as clay, bentonite or hectorite; emulsions such as polyester emulsion resins, acrylic emulsion resins, polyurethane emulsion resins or blocked isocyanates; 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.
  • clay minerals such as clay, bentonite or hectorite
  • emulsions such as polyester emulsion resins, acrylic emulsion resins, polyurethane emulsion resins or blocked isocyanates
  • methylcellulose, carboxymethylcellulose, hydroxyethylcellulose examples thereof include cellulose derivatives such as hydroxypropylcellulose and hydroxypropylmethylcellulose; polysaccharides such as xanthan gum and guar gum
  • a surfactant may be further added.
  • the coating surface becomes rough and the solid content tends to be uneven due to the difference in volatilization rate during drying.
  • the surfactant is not particularly limited, and an anionic surfactant, a cationic surfactant, a nonionic surfactant, and the like can be used. Specific examples include alkyl benzene sulfonate and quaternary ammonium salts. From the viewpoint of obtaining an effect with a small addition amount, a fluorine-based surfactant is more preferable.
  • the viscosity of the conductive paste is preferably 500 cP to 10,000 cP.
  • the viscosity can be measured with a cone plate viscometer (for example, a rheometer MCR301 manufactured by Anton Paar). The measurement is performed at a temperature of 25 ° C., and the viscosity at a cone rotation speed of 50 rpm can be adopted.
  • the viscosity can also be expressed as a shear viscosity, and the paste viscosity at a shear rate of 1 s ⁇ 1 is preferably 0.5 to 20 Pa ⁇ s. More preferably, the paste viscosity at a share rate of 1 s ⁇ 1 is 10 Pa ⁇ s or less, and the paste viscosity at a share rate of 100 s ⁇ 1 is 0.5 Pa ⁇ s or more.
  • Screen printing is also generally used for printing conductive patterns, but screen printing is stencil printing, so if the viscosity is low, paste will flow and it will be difficult to print according to the pattern.
  • a conductive paste having a higher viscosity than that for printing is used.
  • many conductive pastes used for screen printing have a viscosity range of about 50,000 to 100,000 cP. If a gravure plate for gravure offset printing is filled with a conductive paste for screen printing, the viscosity is too high and transfer to the blanket is difficult, and clogging occurs in the concave portion of the gravure plate.
  • the method for producing the conductive paste for gravure offset printing according to the present invention is not particularly limited. First, a silver fine particle dispersion is prepared, and the silver fine particle dispersion, the organic solvent, the water-soluble polymer, and, if necessary.
  • the conductive paste for gravure offset printing of the present invention can be obtained by mixing the above various components.
  • a first step of preparing a mixed solution of a silver compound that can be decomposed by reduction to produce silver and an amine, and reducing the silver compound in the mixed solution And a second step of generating silver fine particles in which the amine is attached to at least a part of the surface.
  • the first step it is preferable to add 2 mol or more of amine with respect to 1 mol of silver.
  • 2 mol or more of amine By making the addition amount of the amine 2 mol or more with respect to 1 mol of silver, an appropriate amount of the amine can be attached to the surface of the silver fine particles produced by reduction, and the silver fine particles are excellently dispersed in various dispersion media. And low-temperature sinterability can be imparted.
  • the composition of the liquid mixture in the first step and the reduction conditions (for example, the heating temperature and the heating time) in the second step are adjusted so that the particle diameter of the obtained silver fine particles is a nanometer size. It is preferable. This is because, by setting the particle diameter of the silver fine particles to a nanometer size, a melting point drop occurs and firing can be performed at a low temperature.
  • the particle diameter of the obtained silver fine particles is more preferably 1 to 200 nm. Micron-sized particles may be included as necessary.
  • the method for taking out the silver fine particles from the silver fine particle dispersion obtained in the second step is not particularly limited, and examples thereof include a method for washing the silver fine particle dispersion.
  • silver salts such as silver nitrate, silver sulfate, silver chloride, silver oxide, silver acetate, silver oxalate, silver formate, silver nitrite, silver chlorate, and silver sulfide. These are not particularly limited as long as they can be reduced, and may be dissolved in an appropriate solvent or may be used as dispersed in a solvent. These may be used alone or in combination. Of these, silver oxalate is preferred.
  • Silver oxalate is the simplest silver dicarboxylate, and the silver oxalate amine complex synthesized using silver oxalate is reduced at a low temperature in a short time. Is preferred. Furthermore, when silver oxalate is used, no by-product is generated during the synthesis, and only carbon dioxide derived from oxalate ions is generated outside the system.
  • Heating is preferred as a method for reducing the silver compound.
  • the heating method is not particularly limited.
  • a method of reducing the silver compound by the heating for example, a complex compound produced from a silver compound such as silver oxalate and an organic component such as amine is heated, and the oxalate ion contained in the complex compound or the like.
  • a method of aggregating atomic silver produced by decomposing a metal compound is mentioned. By the above method, silver fine particles coated with a protective film of an organic component such as amine can be produced.
  • the metal amine complex decomposition method for producing silver fine particles coated with amine by thermally decomposing a complex compound of silver compound in the presence of amine decomposition of silver amine complex which is a single kind of molecule is performed. Since atomic silver is generated by the reaction, it is possible to generate atomic silver uniformly in the reaction system, and the reaction is configured as compared to the case of generating silver atoms by reaction between multiple components. Inhomogeneity of the reaction due to fluctuations in the composition of the components is suppressed, which is particularly advantageous when a large amount of silver powder is produced on an industrial scale.
  • an amine molecule is coordinated to the silver atom to be generated, and the movement of the silver atom during aggregation is controlled by the action of the amine molecule coordinated to the silver atom. Inferred.
  • the metal amine complex decomposition method it is possible to produce metal particles that are very fine and have a narrow particle size distribution.
  • amine molecules form a relatively weak coordination bond on the surface of the silver fine particles to be produced, and these form a dense protective film on the surface of the silver fine particles, so that the storage stability is excellent. It becomes possible to produce organic coated silver fine particles having a clean surface.
  • the amine molecules forming the film can be easily desorbed by heating or the like, silver fine particles that can be sintered at a very low temperature can be produced.
  • the amine is mixed with the dispersant having an acid value constituting the coating of the coated silver fine particles. This facilitates the generation of a complex compound such as a complex compound, and makes it possible to produce the complex compound by mixing in a short time. Further, by mixing and using the amine, it is possible to produce coated silver fine particles having characteristics according to various uses.
  • the dispersion liquid containing silver fine particles coated with an amine or a protective dispersant having an acid value obtained as described above in addition to the silver fine particles, a metal salt counter ion, a dispersant, and a reducing agent residue Etc. exist, and the electrolyte concentration and organic substance concentration of the whole liquid tend to be high.
  • the liquid in such a state is likely to precipitate due to the coagulation of the metal particles due to high electrical conductivity. Or, even if it does not precipitate, if the counter ion of the metal salt, the excessive dispersant more than the amount necessary for dispersion, or the residue of the reducing agent remains, the conductivity may be deteriorated. Therefore, by washing the solution containing the silver fine particles to remove excess residues, the silver fine particles coated with the organic component can be reliably obtained.
  • a dispersion containing silver fine particles having at least a part of the surface coated with an organic component is allowed to stand for a certain period of time, and after removing the supernatant liquid, a solvent that precipitates silver fine particles (for example, water , Methanol, methanol / water mixed solvent, etc.), and a method of repeating the process several times by removing the supernatant liquid by standing again for a certain period of time.
  • a solvent that precipitates silver fine particles for example, water , Methanol, methanol / water mixed solvent, etc.
  • examples of other methods include a method of performing centrifugation instead of the above standing, a method of desalting with an ultrafiltration device, an ion exchange device, or the like.
  • the method for mixing the silver fine particle dispersion, the organic solvent, and the water-soluble polymer is not particularly limited, and can be performed by a conventionally known method using a stirrer or a stirrer.
  • An ultrasonic homogenizer with an appropriate output may be applied by stirring with a spatula or the like.
  • a fine conductive pattern can be formed by a gravure offset printing method using a gravure plate. That is, using the gravure offset printing method using a gravure plate, the gravure plate has a recess filled with a conductive paste for gravure offset printing on the printing surface, the width of the recess is 10 ⁇ m or less,
  • the conductive paste for gravure offset printing is also an embodiment of the present invention, and a method for forming a conductive pattern which is the conductive paste for gravure offset printing of the present invention.
  • FIG. 1 is a conceptual diagram schematically showing an example of a gravure offset printing method.
  • the gravure offset printing apparatus 100 includes a gravure plate 40 and a blanket 50.
  • the gravure offset printing apparatus 100 preferably further includes a pick-up roll 20 for applying the gravure offset printing conductive paste 10 to the gravure plate 40 and a blade 30 for removing excess conductive paste 10.
  • the gravure plate 40 has a recess 41 in which the printing surface is filled with the conductive paste 10 for gravure offset printing.
  • the width W of the recess 41 is 10 ⁇ m or less.
  • a conductive pattern having a line width of 10 ⁇ m or less can be formed.
  • the width W of the recess 41 is preferably 5 ⁇ m or less, and more preferably 3 ⁇ m or less.
  • the gravure offset printing conductive paste of the present invention a fine conductive pattern having a line width of 3 ⁇ m or less is formed without disconnection even when a gravure plate having a width W of 3 ⁇ m or less is used. be able to.
  • the gravure plate 40 may be plate-shaped or cylindrical.
  • the blanket 50 preferably has a silicone rubber layer.
  • the blanket 50 for example, Syl Blanc series manufactured by Kinyo Co., Ltd., # 700-STD manufactured by Fujikura Rubber Industrial Co., Ltd., or the like can be used.
  • the blanket 50 may be plate-shaped or cylindrical.
  • the substrate 60 is not particularly limited as long as it has at least one main surface on which the conductive paste 10 for gravure offset printing can be applied and baked by heating to mount the conductive pattern.
  • it is preferable that it is a base material excellent in heat resistance.
  • the conductive paste for gravure offset printing of the present invention can obtain a conductive pattern having sufficient conductivity even when heated and baked at a lower temperature than conventional conductive inks and conductive pastes. Therefore, it is possible to use a base material having a lower heat-resistant temperature than the conventional one in a temperature range higher than this low firing temperature.
  • Examples of the material constituting the substrate 60 include polyamide (PA), polyimide (PI), polyamideimide (PAI), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene naphthalate (PEN). Examples include polyester, polycarbonate (PC), polyethersulfone (PES), vinyl resin, fluororesin, liquid crystal polymer, ceramics, glass, metal, and the like.
  • the substrate 60 may have various shapes such as a plate shape or a strip shape, and may be rigid or flexible. The thickness of the base material 60 can be appropriately selected. For the purpose of improving adhesion or adhesion, or other purposes, a base material on which a surface layer is formed or a base material that has been subjected to a surface treatment such as a hydrophilic treatment may be used.
  • the conductive pattern forming method includes a coating step of applying the gravure offset printing conductive paste 10 to the substrate 60, and baking the gravure offset printing conductive paste 10 applied to the substrate 60 to conduct the conductive pattern. It is preferable to have a firing step for forming the film.
  • FIG. 1 the arrows shown on the pickup roll 20, the gravure plate 40, and the blanket 50 indicate the respective rotation directions. Moreover, the arrow below the base material 60 indicates the moving direction of the base material 60.
  • the conductive paste 10 is applied to the gravure plate 40 by the pickup roll 20, and the excess conductive paste 10 is removed by the blade 30, whereby the conductive paste 10 is formed in the recess 41 provided on the printing surface of the gravure plate 40. Is filled ((a) of FIG. 1).
  • the conductive paste 10 filled in the concave portion 41 is transferred to the blanket 50 ((b) in FIG. 1).
  • the semi-solid / semi-liquid (wet or semi-dried) conductive paste 10 transferred to the blanket 50 is transferred to the substrate (adhered body) 60 ((c) of FIG. 1).
  • the substrate (adhered body) 60 ((c) of FIG. 1).
  • the conductive paste 10 When a thin line is printed using the conductive paste 10, a transfer defect is likely to occur during transfer from the gravure plate 40 to the blanket 50 and from the blanket 50 to the substrate 60. Since the conductive paste for offset printing contains a water-soluble polymer, the conductive paste 10 transferred onto the blanket 50 is difficult to spread, and has sufficient adhesion and transferability to the substrate 60. For example, even a conductive pattern having a line width of 10 ⁇ m or less, particularly a line width of 3 ⁇ m or less, can be formed without disconnection.
  • the viscosity of the conductive paste 10 may increase due to volatilization of the low boiling point solvent and absorption into the blanket 50 when left for a short time.
  • the organic solvent constituting the conductive paste 10 for gravure offset printing contains a hydroxyl group, the first organic solvent having a boiling point of 200 ° C. or higher at normal pressure, and / or the blanket swelling rate.
  • the second organic solvent When 2.0% or less of the second organic solvent is contained, absorption of the organic solvent into the blanket 50 is reduced, so that drying of the conductive paste 10 on the surface of the blanket 50 can be significantly suppressed. . Therefore, for example, a fine wire conductive pattern having a line width of 3 ⁇ m or less can be more suitably formed.
  • the firing temperature of the conductive paste in the firing step is preferably less than 140 ° C, and more preferably 120 ° C or less.
  • the method for performing the firing is not particularly limited, and for example, a conventionally known gear oven or the like can be used. Since the method for forming a conductive pattern of the present invention uses the conductive paste for gravure offset printing of the present invention, even when heated at a low temperature of less than 140 ° C. (preferably 120 ° C. or less), a conductive material that exhibits high conductivity. Sex patterns can be formed.
  • the lower limit of the firing temperature is not necessarily limited, and is a temperature at which a conductive pattern can be formed on a substrate, and the temperature at which the organic components and the like can be removed by evaporation or decomposition within a range not impairing the effects of the present invention.
  • the method for forming a conductive pattern of the present invention can be heat-treated at a low temperature of about 120 ° C., the conductive pattern can be formed even on a substrate that is relatively weak against heat. Further, the firing time is not particularly limited, and can be appropriately adjusted according to the firing temperature.
  • surface treatment of the substrate may be performed in order to further improve the adhesion between the substrate and the conductive pattern.
  • 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.
  • the film thickness of the conductive pattern after the firing step is, for example, 0.1 to 5 ⁇ m, preferably 0.1 to 1 ⁇ m. Since the method for forming a conductive pattern of the present invention uses the conductive paste for gravure offset printing of the present invention, a conductive pattern having sufficient conductivity can be obtained even when the film thickness is about 0.1 to 5 ⁇ m. It is done.
  • the film thickness t of the conductive pattern can be measured with a laser microscope (for example, a laser microscope VK-9510 manufactured by Keyence Corporation).
  • the film thickness t of the conductive pattern can be obtained using the following formula.
  • Formula: t m / (d ⁇ M ⁇ w)
  • m Weight of the conductive pattern (Measure the weight of the conductive pattern formed on the slide glass with an electronic balance)
  • d Conductive pattern density (g / cm 3 ) (10.5 g / cm 3 in the case of silver)
  • M Conductive pattern length (cm) (Measured length of conductive pattern formed on slide glass on a scale equivalent to JIS class 1)
  • w Conductive pattern width (cm) (Measured width of the conductive pattern formed on the slide glass on a scale equivalent to JIS class 1)
  • the volume resistance value of the conductive pattern obtained by the conductive pattern forming method of the present invention is preferably 110 ⁇ ⁇ cm or less, more preferably 100 ⁇ ⁇ cm or less, and 50 ⁇ ⁇ cm or less. Further preferred.
  • the volume resistance value can be measured, for example, by the following method. First, a conductive paste pattern with a width of 1 mm and a length of 1.5 cm is formed on a PET substrate, and sintered by baking at 120 ° C. for 30 minutes in a gear oven to form a coating (conductive pattern) To do. Thereafter, the resistance value R of the coating and the thickness t of the coating are measured.
  • the resistance value R of the film can be measured using, for example, “Digital Multimeter PM-3” manufactured by Sanwa Electric Instruments Co., Ltd.
  • the thickness t of the coating can be measured, for example, using a shape measurement laser microscope “VK-X100” manufactured by Keyence Corporation. From the obtained value, the volume resistance value can be converted based on the following formula (1).
  • (Volume resistance value ⁇ v) (resistance value R) ⁇ (film width w) ⁇ (film thickness t) / (distance L between terminals)
  • the manufacturing method of the conductive substrate which draws a conductive pattern on a base material using the formation method of the conductive pattern of the present invention is also one mode of the present invention.
  • the thing similar to the base material demonstrated with the formation method of the electroconductive pattern of this invention can be used.
  • the method for producing a conductive substrate of the present invention uses the method for forming a conductive pattern using the conductive paste for gravure offset printing of the present invention, for example, a thin wire having a line width of 10 ⁇ m or less, particularly a line width of 3 ⁇ m or less.
  • a conductive pattern can be formed. Therefore, a conductive substrate provided with a precise electronic circuit can be manufactured.
  • the conductive substrate include an electronic circuit substrate.
  • the conductive pattern is, for example, a wiring formed on an electronic circuit board.
  • the obtained mixed solution was transferred to an oil bath and heated and stirred at 120 ° C.
  • the reaction with the generation of carbon dioxide started immediately after the start of stirring, and then stirring was performed until the generation of carbon dioxide was completed, thereby obtaining a suspension in which silver fine particles were suspended in the amine mixture (No. 1). 2 steps).
  • the average particle diameter of the silver fine particles contained in the silver fine particle dispersion obtained in Synthesis Example 1 was 32 nm.
  • the average particle size is calculated by the dynamic light scattering method using a particle size distribution measuring device (model number: LB-550) manufactured by Horiba, Ltd. by diluting the obtained silver fine particle dispersion 100 times with a dispersion solvent. did. Turpineol was used as a dispersion solvent, and the solvent refractive index was measured as 1.383.
  • a water-soluble polymer mixed solution was prepared by dissolving 3.0 parts by weight of polyvinylpyrrolidone K30 as a water-soluble polymer in an organic solvent in which 3.0 parts by weight of Kyowadiol PD-9 and 14.0 parts by weight of terpineol were mixed. . If the above water-soluble polymer is difficult to dissolve, it may be heated as necessary.
  • Example 2 Example 1 except that the water-soluble polymer added is changed from 3.0 parts by weight of polyvinylpyrrolidone K30 to 3.0 parts by weight of polyvinylpyrrolidone K25 with respect to 80 parts by weight of the silver fine particle dispersion of Synthesis Example 1. Similarly, a conductive paste according to Example 2 was obtained.
  • Example 3 In Example 3, submicron-sized silver fine particles (submicron silver) (manufactured by Rare Metal Materials Laboratory, particle size distribution 0.2 to 1.0 ⁇ m) were used as silver fine particles. .
  • As the water-soluble polymer mixed solution 3.0 parts by weight of Kyowadiol PD-9 as an organic solvent and 13.0 parts by weight of terpineol, 3.0 parts by weight of polyvinylpyrrolidone K30 as a water-soluble polymer, A mixed solution in which 0.5 part by weight of CrystasenseMP was dissolved as a thickener and 0.5 part by weight of SOLPERSE41000 was dissolved as a polymer dispersant was used.
  • a conductive paste according to Example 3 was obtained in the same manner as Example 1 except that 20 parts by weight of the water-soluble polymer mixed solution was added to 80.0 parts by weight of the submicron-sized silver fine particles. It was.
  • Example 4 As silver fine particles, 60.0 parts by weight of the silver fine particle dispersion of Synthesis Example 1 and the submicron-sized silver fine particles used in Example 3 (manufactured by Rare Metals Laboratory, Inc., particle size distribution 0.2 to 1.0 ⁇ m) What mixed 20.0 weight part was used.
  • the conductivity according to Example 4 was the same as Example 1 except that 20.0 parts by weight of the water-soluble polymer mixed solution prepared in Example 3 was added to 80.0 parts by weight of the silver fine particles. A paste was obtained.
  • Example 5 In Example 5, instead of the organic solvent in which 3.0 parts by weight of Kyowadiol PD-9 and 14.0 parts by weight of terpineol were mixed, 3.0 weight parts of 2-ethyl-1,3-hexanediol isomer mixture was used. An organic solvent mixed with 14.0 parts by weight of terpineol was used. A conductive paste according to Example 5 was obtained in the same manner as in Example 1 except that 17.0 parts by weight of the mixed organic solvent was added to 80.0 parts by weight of the silver fine particle dispersion of Synthesis Example 1. It was.
  • Example 6 An organic solvent containing only 2-ethyl-1,3-hexanediol isomer mixture was used without mixing terpineol.
  • Example 1 was repeated except that 17.0 parts by weight of the 2-ethyl-1,3-hexanediol isomer mixture was added to 80.0 parts by weight of the silver fine particle dispersion of Synthesis Example 1.
  • a conductive paste according to Example 6 was obtained.
  • Example 7 The addition amount of the water-soluble polymer was changed from 3.0 parts by weight to 7.0 parts by weight, and an organic solvent mixed with 3.0 parts by weight of Kyowadiol PD-9 and 10.0 parts by weight of terpineol was used. A conductive paste according to Example 7 was obtained in the same manner as Example 1 except that.
  • Example 8> The addition amount of the water-soluble polymer was changed from 3.0 parts by weight to 8.0 parts by weight, and an organic solvent mixed with 3.0 parts by weight of Kyowadiol PD-9 and 9.0 parts by weight of terpineol was used.
  • a conductive paste according to Example 8 was obtained in the same manner as Example 1 except that.
  • Comparative Example 1 was carried out in the same manner as in Example 1 except that 3.0 parts by weight of non-water-soluble polyvinyl acetoacetal resin (manufactured by Sekisui Chemical Co., Ltd., ESREC KS-10) was added instead of polyvinyl pyrrolidone K30. Such a conductive paste was obtained.
  • Comparative Example 3 A conductive paste according to Comparative Example 3 was obtained in the same manner as Example 1 except that 3.0 parts by weight of polymethyl methacrylate that was not water-soluble was added instead of polyvinyl pyrrolidone K30.
  • Comparative example 4 A conductive paste according to Comparative Example 4 was obtained in the same manner as in Example 1 except that 3.0 parts by weight of a non-water-soluble vinyl chloride-vinyl acetate copolymer (Sorvain AL) was added instead of polyvinylpyrrolidone K30. It was.
  • a non-water-soluble vinyl chloride-vinyl acetate copolymer Sorvain AL
  • Comparative Example 5 A conductive paste according to Comparative Example 5 was obtained in the same manner as in Example 1 except that 3.0 parts by weight of a non-water-soluble vinyl chloride-vinyl acetate copolymer (Sorvain M5) was added instead of polyvinyl pyrrolidone K30. It was.
  • a non-water-soluble vinyl chloride-vinyl acetate copolymer (Sorvain M5) was added instead of polyvinyl pyrrolidone K30. It was.
  • Example 6 The same operation as in Example 1 was performed except that 3.0 parts by weight of non-water-soluble amorphous polyester resin (Byron 200) was added instead of polyvinylpyrrolidone K30, but Byron 200 was dissolved in the solvent. No conductive paste was obtained.
  • Byron 200 non-water-soluble amorphous polyester resin
  • the blanket was cut into 1 cm length and 1 cm width, and the weight was measured. Thereafter, the cut blanket was completely immersed in various organic solvents (20 g) and left for 10 hours. Immersion was performed under room temperature conditions (25 ° C. ⁇ 5 ° C.). After 10 hours, the blanket was taken out from each organic solvent, the adhered solvent was wiped off, the weight of the blanket after immersion was measured within 1 minute, and the weight increase rate before and after immersion was determined. The obtained numerical value was defined as the blanket swelling rate. Table 1 below shows the boiling point of each organic solvent and the measured blanket swelling rate.
  • Dilutable conductive paste was diluted 100 times with a dispersion medium (terpineol), and the dispersibility immediately after the dilution (initial) and the dispersibility after standing at room temperature for 1 week were evaluated visually.
  • the case where aggregation or silver mirror was not observed was evaluated as “ ⁇ ”
  • the case where aggregation / precipitation occurred was evaluated as “x”.
  • the concave portions of the first and second gravure plates are filled with the conductive pastes of the examples and comparative examples by a doctor blade, and then pressed and brought into contact with a rubber roller around which a silicone blanket is wound so that a desired pattern is formed on the blanket.
  • a silicone blanket was pressed and transferred to a sheet of PET film (thickness: 100 ⁇ m) and printed to produce printed patterns (printed wiring) having line widths of about 3 ⁇ m and 5 ⁇ m.
  • the silicone blanket Silblanc SP11-1 (rubber layer 0.6 mm, PET layer 0.25 mm) manufactured by Kinyo Co., Ltd. was used.
  • Adhesion test Adhesion was evaluated by the pull-off method. The evaluation was performed based on the state of rupture when Cellotape (registered trademark) was affixed to the printed wiring on the PET substrate used for the printability evaluation and peeled off. Specifically, the tape was strongly rubbed against five places of the printed wiring, and was peeled off in the vertical direction for evaluation. When the number of cellophane tapes that have been peeled off is 0 to 1, “ ⁇ ” is used for 2 to 3 sheets, “ ⁇ ” is used for 4 to 5 sheets, and “ ⁇ ” is used for 4 to 5 sheets. Even if it was a typical peeling, it was assumed that it was peeled and counted as one sheet.
  • Cellotape registered trademark
  • a pattern of the conductive paste having a width of 1 mm and a length of 1.5 cm is formed on the PET substrate.
  • Sintering was performed by firing at 120 ° C. for 30 minutes in a gear oven to form a coating (conductive pattern).
  • the resistance value R at both ends of the coating was measured.
  • the thickness t of the coating was measured using a shape measurement laser microscope “VK-X100” manufactured by Keyence Corporation. Then, based on the following formula (1), the volume resistance value was converted from the distance between the measurement terminals and the thickness t of the coating.
  • the conductive pastes of Examples 1 to 8 were all excellent in dispersibility and dilutability.
  • a conductive pattern with a width of 3 ⁇ m could be formed by gravure offset printing.
  • Examples 1, 2, and 5-8 using only nanometer-sized silver fine particles have higher printability
  • the results of Examples 3 and 4 show that not only nanometer-sized silver fine particles but also sub It has been found that a conductive pattern having a narrow line width can be printed by using micron-sized silver fine particles alone or by mixing nanometer-sized and submicron-sized silver fine particles.
  • Example 8 in which the addition amount of the water-soluble polymer was 8 parts by weight, fine line printing was possible although the volume resistance value was slightly increased.
  • the number of hydroxyl groups in the organic solvent is not a problem because it is possible to form a fine line only with a diol solvent without using a terpene solvent as the organic solvent. .

Abstract

Provided is a conductive paste for gravure offset printing, which has sufficient conductivity and good adhesion to substrates, and enables fine line printing. This conductive paste for gravure offset printing contains silver particles, an organic solvent, and a water-soluble polymer. The silver particles have an average particle size of 1 μm or less. The water-soluble polymer preferably contains a polymerizable compound having a cyclic structure, and more preferably contains polyvinyl pyrrolidone.

Description

グラビアオフセット印刷用導電性ペースト、導電性パターンの形成方法、及び、導電性基板の製造方法Conductive paste for gravure offset printing, method for forming conductive pattern, and method for manufacturing conductive substrate
本発明は、グラビアオフセット印刷用導電性ペースト、上記グラビアオフセット印刷用導電性ペーストを用いた導電性パターンの形成方法、及び、上記導電性パターンの形成方法を用いた導電性基板の製造方法に関する。 The present invention relates to a conductive paste for gravure offset printing, a method for forming a conductive pattern using the conductive paste for gravure offset printing, and a method for manufacturing a conductive substrate using the method for forming the conductive pattern.
近年、印刷技術を利用して電子回路、デバイス等を形成するプリンテッドエレクトロニクス技術が注目されている。上記プリンテッドエレクトロニクス技術においては、より簡便かつ安価な導電性パターンの形成方法として、凸版印刷法、凹版印刷法、スクリーン印刷法又はインクジェット印刷法等の印刷法を用いることが検討されており、それぞれの印刷法に適した導電性インクや導電性ペースト等が研究開発されている。 In recent years, printed electronics technology that forms electronic circuits, devices, and the like using printing technology has attracted attention. In the printed electronics technology, it has been studied to use a printing method such as a relief printing method, an intaglio printing method, a screen printing method or an ink jet printing method as a simpler and cheaper method for forming a conductive pattern, respectively. Conductive inks and conductive pastes suitable for the printing method are being researched and developed.
例えば、特許文献１においては、導電性金属粒子（Ａ）と、５０℃において固体であり常圧における沸点が３００℃を超える有機化合物（Ｂ）と、５０℃において液体であり常圧における沸点が３００℃を超える有機化合物（Ｃ）と、（Ｂ）及び（Ｃ）以外の、（Ｂ）及び（Ｃ）と反応性を有さない常圧における沸点１７０～３００℃の有機溶剤（Ｄ）とを含有する、グラビアオフセット印刷法によるベゼルパターン印刷用導電性ペーストであって、（Ｂ）不揮発分を、（Ａ）～（Ｄ）の合計に対し、質量換算で１．０～３．０％とし、かつ、不揮発分の質量換算で、有機化合物（Ｂ）と有機化合物（Ｃ）の合計使用量をＲ、導電性金属粒子（Ａ）の使用量をＰとした際の両者の質量比Ｒ／Ｐを、０．０７～０．１５とすることを特徴とする導電性ペーストが開示されている。 For example, in Patent Document 1, a conductive metal particle (A), an organic compound (B) that is solid at 50 ° C. and has a boiling point at normal pressure exceeding 300 ° C., and a liquid that is liquid at 50 ° C. and has a boiling point at normal pressure. An organic compound (C) having a boiling point of 170 to 300 ° C. at normal pressure, which is not reactive with (B) and (C), other than (B) and (C); A conductive paste for bezel pattern printing by a gravure offset printing method, containing (B) a non-volatile content of 1.0 to 3.0% in terms of mass with respect to the total of (A) to (D) And, in terms of the mass of the non-volatile content, the total use amount of the organic compound (B) and the organic compound (C) is R and the use amount of the conductive metal particles (A) is P. / P is set to 0.07 to 0.15 It discloses conductive paste.
また、特許文献２には、熱硬化性樹脂成分またはガラス・フリットを配合していない導電性銅ペーストを用いた導電膜の製造方法が開示されており、前記導電性銅ペーストとして、平均粒子径が２μｍ～１０μｍの範囲に選択される銅粉、平均粒子径が０．２μｍ～１．０μｍの範囲に選択される微細銅粉、特定の脂肪族モノカルボン酸の銅塩、特定の（ジアルキルアミノ）アルキルアミン、熱分解温度が特定範囲のポリマーバインダー、及び、沸点が特定範囲であり、特定の官能基を有する第一の有機溶媒を、それぞれ特定量含む導電性銅ペーストを用い、前記導電性銅ペーストを樹脂基材上に付与した後に、前記第一の有機溶媒の残留量が０．１～５質量％となる状態で、光照射し、成膜することを特徴とする導電膜の製造方法が開示されている。 Patent Document 2 discloses a method for producing a conductive film using a conductive copper paste that does not contain a thermosetting resin component or glass frit, and the conductive copper paste has an average particle diameter. Selected from the range of 2 μm to 10 μm, fine copper powder selected from the average particle size of 0.2 μm to 1.0 μm, a copper salt of a specific aliphatic monocarboxylic acid, a specific (dialkylamino ) Using the conductive copper paste containing a specific amount of alkylamine, a polymer binder having a thermal decomposition temperature in a specific range, and a first organic solvent having a specific functional group having a boiling point in a specific range, Production of a conductive film, characterized in that after applying a copper paste on a resin substrate, light irradiation is performed in a state where the residual amount of the first organic solvent is 0.1 to 5% by mass. A method is disclosed There.
導電性基板の導電性パターンの形成には、細線の印刷に適していることから、上記凹版印刷法の一種であるグラビアオフセット印刷が好適に用いられる。グラビアオフセット印刷では、グラビア版の表面に形成された凹部に導電性ペーストを充填し、上記導電性ペーストを一旦ブランケットに転写し、上記ブランケットに転写された導電性ペーストを被着体に転写することにより、グラビア版の表面に形成された印刷パターンを被着体上に印刷する。そのため、グラビアオフセット印刷用の導電性ペーストは、グラビア版の凹部に充填しやすいように適度な粘度を有すること、グラビア版からブランケットへの転写、及び、ブランケットから被着体への転写を良好にするために、半固体／半液体状態で程度な粘着性（タック）を有することが求められる。 For the formation of the conductive pattern on the conductive substrate, gravure offset printing, which is a kind of the intaglio printing method, is suitably used because it is suitable for fine line printing. In gravure offset printing, a conductive paste is filled in a recess formed on the surface of a gravure plate, the conductive paste is temporarily transferred to a blanket, and the conductive paste transferred to the blanket is transferred to an adherend. Thus, the print pattern formed on the surface of the gravure plate is printed on the adherend. Therefore, the conductive paste for gravure offset printing has an appropriate viscosity so that it can be easily filled in the concave portion of the gravure plate, and the transfer from the gravure plate to the blanket and the transfer from the blanket to the adherend are good. In order to achieve this, it is required to have a degree of tackiness (tack) in a semisolid / semiliquid state.
特許第５６１０１１２号公報Japanese Patent No. 5610112 特開２０１４－１８６９０２号公報JP 2014-186902 A
近年、電子回路の高密度化が進み、配線についてもさらなる微細化が検討されている。特に、線幅が１０μｍ以下の導電性パターンを形成することが要求されており、更に精密な電子回路では、線幅が３μｍ以下の導電性パターンを形成することが求められている。従来、導電性ペーストに粘度や粘着性を付与するための樹脂材として、アクリル樹脂、ポリエステル樹脂、ウレタン樹脂等が用いられてきた。また、溶媒としては、比較的極性の低い有機溶剤が用いられることが多かった。しかしながら、アクリル樹脂、ポリエステル樹脂、ウレタン樹脂等の樹脂材と有機溶剤との組み合わせは、半固体／半液体状態での粘着性が低いため、特にグラビアオフセット印刷法を用いて細線印刷を行う場合には、転写不良が起こりやすく、断線のない細線印刷を行うことは非常に困難であった。また、線幅が３μｍ以下の細線を形成する場合には、被着体への密着性が非常に重要であり、半固体／半液体状態での粘着性と被着体への密着性を有するグラビアオフセット印刷用導電性ペーストが求められていた。 In recent years, the density of electronic circuits has been increased, and further miniaturization of wiring has been studied. In particular, it is required to form a conductive pattern having a line width of 10 μm or less, and a more precise electronic circuit is required to form a conductive pattern having a line width of 3 μm or less. Conventionally, acrylic resins, polyester resins, urethane resins and the like have been used as resin materials for imparting viscosity and tackiness to conductive pastes. Moreover, as a solvent, the organic solvent with comparatively low polarity was often used. However, the combination of resin materials such as acrylic resin, polyester resin, urethane resin and organic solvent has low adhesiveness in a semi-solid / semi-liquid state, so when performing thin line printing using the gravure offset printing method in particular. However, it is very difficult to perform fine line printing without breakage due to transfer failure. In addition, when forming a thin line having a line width of 3 μm or less, adhesion to an adherend is very important, and it has adhesiveness in a semi-solid / semi-liquid state and adhesion to an adherend. There has been a need for a conductive paste for gravure offset printing.
上記特許文献１に記載の導電性ペーストは、ベゼルパターンの印刷に向けて設計されており、近年の導電性パターンの細線化に対応するためには、更なる検討の余地があった。また、上記特許文献２では、グラビアオフセット印刷によって形成される導電性パターンの細線化について検討されていない。 The conductive paste described in Patent Document 1 is designed for printing a bezel pattern, and there is room for further study in order to cope with the thinning of the conductive pattern in recent years. Moreover, in the said patent document 2, it is not examined about the thinning of the conductive pattern formed by gravure offset printing.
本発明は、上記課題に鑑みてなされたものであり、充分な導電性及び基板との良好な密着性を有し、微細導電性パターンを形成することができるグラビアオフセット印刷用導電性ペースト、導電性パターンの形成方法、及び、導電性基板の製造方法を提供する。 The present invention has been made in view of the above problems, and has a sufficient conductivity and good adhesion to a substrate and can form a fine conductive pattern, a conductive paste for gravure offset printing, and a conductive material. A method for forming a conductive pattern and a method for manufacturing a conductive substrate are provided.
本発明者らは、上記目的を達成すべく鋭意研究を重ねた結果、グラビアオフセット印刷法によって形成される導電性パターンの細線化を図るために、導電性ペーストに水溶性高分子を添加することで、半固体／半液体状態での粘着性が向上し、グラビアオフセット印刷により細線印刷が可能となることを見出し、本発明に到達した。 As a result of intensive studies to achieve the above object, the present inventors have added a water-soluble polymer to the conductive paste in order to thin the conductive pattern formed by the gravure offset printing method. Thus, the present inventors have found that the adhesiveness in a semi-solid / semi-liquid state is improved and fine line printing is possible by gravure offset printing, and the present invention has been achieved.
本発明のグラビアオフセット印刷用導電性ペーストは、銀微粒子と、有機溶媒と、水溶性高分子とを含有し、上記銀微粒子の平均粒子径は１μｍ以下であることを特徴とする。 The conductive paste for gravure offset printing of the present invention contains silver fine particles, an organic solvent, and a water-soluble polymer, and the average particle size of the silver fine particles is 1 μm or less.
上記水溶性高分子は、環状構造を有する重合性化合物を含有することが好ましい。 The water-soluble polymer preferably contains a polymerizable compound having a cyclic structure.
上記水溶性高分子は、ポリビニルピロリドンを含有することが好ましい。 The water-soluble polymer preferably contains polyvinyl pyrrolidone.
上記水溶性高分子の含有量は、上記導電性ペースト全体に対して、３～８重量％であることが好ましい。 The content of the water-soluble polymer is preferably 3 to 8% by weight with respect to the entire conductive paste.
上記有機溶媒は、ヒドロキシル基を含有し、常圧での沸点が２００℃以上である第１の有機溶媒を含有することが好ましい。 The organic solvent preferably contains a first organic solvent containing a hydroxyl group and having a boiling point of 200 ° C. or higher at normal pressure.
上記有機溶媒は、ブランケット膨潤率が２．０％以下の第２の有機溶媒を、上記導電性ペースト全体に対して、３．０～３０重量％含有することが好ましい。 The organic solvent preferably contains 3.0 to 30% by weight of a second organic solvent having a blanket swelling ratio of 2.0% or less based on the entire conductive paste.
本発明の導電性パターンの形成方法は、グラビア版を用いたグラビアオフセット印刷法を用い、上記グラビア版は、印刷面にグラビアオフセット印刷用導電性ペーストが充填される凹部を有し、上記凹部の幅は、１０μｍ以下であり、上記グラビアオフセット印刷用導電性ペーストは、本発明のグラビアオフセット印刷用導電性ペーストであることを特徴とする。 The method for forming a conductive pattern of the present invention uses a gravure offset printing method using a gravure plate, and the gravure plate has a recess filled with a conductive paste for gravure offset printing on the printing surface, The width is 10 μm or less, and the gravure offset printing conductive paste is the gravure offset printing conductive paste of the present invention.
本発明の導電性基板の製造方法は、本発明の導電性パターンの形成方法を用いて、基材上に導電性パターンを描画することを特徴とする。 The method for producing a conductive substrate of the present invention is characterized in that a conductive pattern is drawn on a substrate using the method for forming a conductive pattern of the present invention.
本発明のグラビアオフセット印刷用導電性ペーストは、充分な導電性及び基板との良好な密着性を有するため、グラビアオフセット印刷による細線印刷が可能である。また、本発明の導電性パターンの形成方法によれば、線幅が１０μｍ以下の導電性パターンを形成することができ、線幅が３μｍ以下の導電性パターンであっても断線することなく形成することができる。本発明の導電性基板の製造方法によれば、精密な導電性パターンが印刷された導電性基板を製造することができる。 Since the conductive paste for gravure offset printing of the present invention has sufficient conductivity and good adhesion to a substrate, fine line printing by gravure offset printing is possible. Moreover, according to the method for forming a conductive pattern of the present invention, a conductive pattern having a line width of 10 μm or less can be formed, and even a conductive pattern having a line width of 3 μm or less is formed without disconnection. be able to. According to the method for manufacturing a conductive substrate of the present invention, a conductive substrate on which a precise conductive pattern is printed can be manufactured.
グラビアオフセット印刷法の一例を模式的に示した概念図である。It is the conceptual diagram which showed typically an example of the gravure offset printing method.
［グラビアオフセット印刷用導電性ペースト］
本発明のグラビアオフセット印刷用導電性ペーストは、銀微粒子と、有機溶媒と、水溶性高分子とを含有し、上記銀微粒子の平均粒子径は１μｍ以下であることを特徴とする。本発明のグラビアオフセット印刷用導電性ペーストは、有機溶媒と水溶性高分子とを含有するため、乾きにくく、かつ、半固体／半液体状態で程度な粘着性を有するため、グラビアオフセット印刷法による細線印刷に好適である。 [Conductive paste for gravure offset printing]
The conductive paste for gravure offset printing of the present invention contains silver fine particles, an organic solvent, and a water-soluble polymer, and the average particle size of the silver fine particles is 1 μm or less. Since the conductive paste for gravure offset printing of the present invention contains an organic solvent and a water-soluble polymer, it is difficult to dry and has a degree of adhesiveness in a semi-solid / semi-liquid state. Suitable for fine line printing.
（銀微粒子）
上記銀微粒子の平均粒子径は１μｍ以下である。上記銀微粒子の平均粒子径を１μｍ以下とすることで、グラビアオフセット印刷法を用いて、例えば線幅が３μｍ以下の微細な導電性パターンを形成することができる。上記銀微粒子の形状については、本発明の効果を損なわない限りにおいて特に限定されない。平均粒子径が１μｍを超える粗大な銀粒子を用いると、例えばグラビア版の表面に形成された凹部の幅が３μｍである場合には、銀粒子を数個しか充填できないため、銀粒子同士の焼結が困難であり、微細な導電性パターンを形成することができない。更に、銀粒子の粒子径によっては、上記３μｍ幅の凹部に全く銀粒子を充填できない場合もある。 (Silver fine particles)
The average particle diameter of the silver fine particles is 1 μm or less. By setting the average particle diameter of the silver fine particles to 1 μm or less, a fine conductive pattern having a line width of 3 μm or less, for example, can be formed using a gravure offset printing method. The shape of the silver fine particles is not particularly limited as long as the effects of the present invention are not impaired. When coarse silver particles having an average particle diameter exceeding 1 μm are used, for example, when the width of the recess formed on the surface of the gravure plate is 3 μm, only a few silver particles can be filled. It is difficult to form a fine conductive pattern. Furthermore, depending on the particle diameter of the silver particles, there may be a case where the silver particles cannot be filled at all in the 3 μm-wide recess.
上記銀微粒子としては、融点降下が生じるような平均粒子径を有するものが好ましく、例えば、平均粒子径が１～２００ｎｍであるナノメートルサイズの銀微粒子を含むことがより好ましい。上記ナノメートルサイズの銀微粒子を含むことで上記グラビア版の凹部に多数の銀微粒子を緻密に充填し、銀微粒子同士を細かく重なり合うように並べることができるため、銀微粒子同士を焼結（ネッキング）させることが容易である。加えて、粒子径が極めて小さいことから、一つの銀微粒子が印刷品質に与える影響をより低減することができる。上記銀微粒子の平均粒子径が１ｎｍ以上であれば、銀微粒子が良好な低温焼結性を具備すると共に銀微粒子の製造にかかるコストを抑制でき実用的である。また、上記銀微粒子の平均粒子径が２００ｎｍ以下であれば、銀微粒子の分散性が経時的に変化しにくい。上記銀微粒子の平均粒子径の更に好ましい下限は２ｎｍであり、更に好ましい上限は１００ｎｍである。 The silver fine particles preferably have an average particle size that causes a melting point drop. For example, it is more preferable to include nanometer-sized silver fine particles having an average particle size of 1 to 200 nm. By including the nanometer-sized silver fine particles, the gravure plate can be densely filled with a large number of silver fine particles, and the silver fine particles can be arranged so as to overlap each other, so that the silver fine particles are sintered (necking). It is easy to make. In addition, since the particle diameter is extremely small, the influence of one silver fine particle on the print quality can be further reduced. If the average particle diameter of the silver fine particles is 1 nm or more, the silver fine particles have good low-temperature sinterability, and the production cost of the silver fine particles can be suppressed, which is practical. Further, when the average particle size of the silver fine particles is 200 nm or less, the dispersibility of the silver fine particles hardly changes over time. The more preferable lower limit of the average particle diameter of the silver fine particles is 2 nm, and the more preferable upper limit is 100 nm.
上記銀微粒子は、平均粒子径が２００ｎｍを超え、１μｍ以下のサブミクロンサイズの銀微粒子を含有してもよい。サブミクロンサイズの銀微粒子を用いると、銀微粒子の粒子径が大きいため、銀微粒子同士の焼結性がやや低下するものの、充分に細線印刷が可能である。 The silver fine particles may contain submicron-sized silver fine particles having an average particle diameter of more than 200 nm and 1 μm or less. When submicron-sized silver fine particles are used, the silver fine particles have a large particle diameter, so that the sinterability between the silver fine particles is slightly lowered, but sufficient thin line printing is possible.
上記銀微粒子は、平均粒子径が１～２００ｎｍであるナノメートルサイズの銀微粒子と、平均粒子径が２００ｎｍを超え、１μｍ以下のサブミクロンサイズの銀微粒子とを含有してもよい。ナノメートルサイズの銀微粒子とサブミクロンサイズの銀微粒子とを併用することで、ナノメートルサイズの銀微粒子がサブミクロンサイズの銀微粒子の周囲で融点降下することにより、サブミクロンサイズの銀微粒子のみを用いた場合よりも、良好な導電パスを得ることができる。 The silver fine particles may contain nanometer-sized silver fine particles having an average particle diameter of 1 to 200 nm and submicron-sized silver fine particles having an average particle diameter of more than 200 nm and not more than 1 μm. By using nanometer-sized silver fine particles and submicron-sized silver fine particles in combination, the nanometer-sized silver fine particles drop in melting point around the submicron-sized silver fine particles, so that only the submicron-sized silver fine particles are obtained. A better conductive path can be obtained than when it is used.
上記銀微粒子の粒子径は、動的光散乱法、小角Ｘ線散乱法、広角Ｘ線回折法で測定することができる。本明細書中、「平均粒子径」とは、分散メジアン径をいう。上記分散メジアン径は、動的光散乱法（Ｄｙｎａｍｉｃ　Ｌｉｇｈｔ　Ｓｃａｔｔｅｒｉｎｇ）にて、粒子径基準を体積基準として、分散粒径を得ることで算出される。ＤＬＳの測定装置としては、例えば、堀場製作所社製の粒子径分布測定装置（型番：ＬＢ－５５０）を用いることができる。具体的には、合成した銀微粒子分散体をターピネオールで１００倍希釈し、溶媒屈折率を１．４８３として測定する。 The particle diameter of the silver fine particles can be measured by a dynamic light scattering method, a small angle X-ray scattering method, or a wide angle X-ray diffraction method. In the present specification, the “average particle diameter” refers to a dispersion median diameter. The dispersion median diameter is calculated by obtaining a dispersed particle diameter by using a dynamic light scattering method (Dynamic Light Scattering) with a particle diameter reference as a volume reference. As a DLS measuring device, for example, a particle size distribution measuring device (model number: LB-550) manufactured by Horiba, Ltd. can be used. Specifically, the synthesized silver fine particle dispersion is diluted 100 times with terpineol, and the solvent refractive index is measured as 1.383.
上記導電性ペーストの不揮発分全体に対する上記銀微粒子の重量比率は、９０重量％以上であることが好ましい。上記不揮発分とは、有機溶媒以外の成分をいい、銀微粒子の他に、後述する銀微粒子を被覆する有機成分、導電性ペーストに含まれる水溶性高分子、高分子分散剤、増粘剤等が含まれる。上記銀微粒子の重量比率が９０重量％以上であることで、銀含有率の高い導電性パターンを形成することができる。銀微粒子は、化学的な安定性に優れるため、銀微粒子をメインとすることで、酸化し難く、体積抵抗値が低下し難い導電性パターンを形成することができる。 The weight ratio of the silver fine particles to the whole nonvolatile content of the conductive paste is preferably 90% by weight or more. The non-volatile content refers to components other than organic solvents, in addition to silver fine particles, organic components that cover silver fine particles described later, water-soluble polymers contained in conductive paste, polymer dispersants, thickeners, etc. Is included. When the weight ratio of the silver fine particles is 90% by weight or more, a conductive pattern having a high silver content can be formed. Since the silver fine particles are excellent in chemical stability, by using silver fine particles as the main, it is possible to form a conductive pattern that is difficult to be oxidized and whose volume resistance value is difficult to decrease.
また、本発明のグラビアオフセット印刷用導電性ペーストを用いて形成される導電性パターンのマイグレーションの問題を考慮して、イオン化列が水素より貴である金属、即ち金、銅、白金、パラジウム等の粒子を添加してもよい。本発明のグラビアオフセット印刷用導電性ペーストが銀以外の金属粒子を含有する場合、銀微粒子と銀以外の金属粒子とを合わせた金属粒子全体に対する、銀微粒子の含有比率は、９０重量％以上であることが好ましい。 Further, considering the problem of migration of the conductive pattern formed using the conductive paste for gravure offset printing of the present invention, a metal whose ionization column is more noble than hydrogen, that is, gold, copper, platinum, palladium, etc. Particles may be added. When the conductive paste for gravure offset printing of the present invention contains metal particles other than silver, the content ratio of the silver fine particles to the total metal particles including the silver fine particles and the metal particles other than silver is 90% by weight or more. Preferably there is.
（有機成分）
上記銀微粒子の表面の少なくとも一部には有機成分が付着していることが好ましい。上記銀微粒子の表面は、有機成分で被覆されていることがより好ましい。被覆の形態については特に限定されないが、上記有機成分は、いわゆる分散剤として上記銀微粒子とともに実質的に無機コロイド粒子を構成する。上記有機成分には、銀微粒子に最初から不純物として含まれる微量有機物、後述する製造過程で混入して銀微粒子に付着した微量有機物、洗浄過程で除去しきれなかった残留還元剤、残留分散剤等のように、銀微粒子に微量付着した有機物等は含まれない概念である。なお、上記「微量」とは、具体的には、無機コロイド粒子中１重量％未満が意図される。 (Organic component)
It is preferable that an organic component adheres to at least a part of the surface of the silver fine particles. The surface of the silver fine particles is more preferably coated with an organic component. Although it does not specifically limit about the form of coating | cover, The said organic component comprises an inorganic colloid particle substantially with the said silver fine particle as what is called a dispersing agent. The organic component includes trace organic substances contained in the silver fine particles as impurities from the beginning, trace organic substances adhering to the silver fine particles mixed in the manufacturing process described later, residual reducing agent that could not be removed in the cleaning process, residual dispersant, etc. As described above, it is a concept that does not include organic substances or the like adhered to silver fine particles. The “trace amount” specifically means less than 1% by weight in the inorganic colloidal particles.
上記有機成分は、銀微粒子を被覆して銀微粒子の凝集を防止するとともに無機コロイド粒子を形成することが可能な有機物であり、分散性及び導電性等の観点から、アミン及びカルボン酸を含むことが好ましい。なお、これらの有機成分は、銀微粒子と化学的あるいは物理的に結合している場合、アニオンやカチオンに変化していることも考えられ、これらの有機成分に由来するイオンや錯体等も上記有機成分に含まれる。 The organic component is an organic substance capable of covering silver fine particles to prevent aggregation of silver fine particles and forming inorganic colloidal particles, and contains an amine and a carboxylic acid from the viewpoint of dispersibility and conductivity. Is preferred. In addition, when these organic components are chemically or physically bonded to the silver fine particles, it may be considered that they are changed to anions and cations, and ions and complexes derived from these organic components are also Contained in the ingredients.
上記アミンとしては、直鎖状であっても分岐鎖状であってもよく、また、側鎖を有していてもよい。具体的には、Ｎ－（３－メトキシプロピル）プロパン－１，３－ジアミン、１，２－エタンジアミン、２－メトキシエチルアミン、３－メトキシプロピルアミン、３－エトキシプロピルアミン、１，４－ブタンジアミン、１，５－ペンタンジアミン、ペンタノールアミン、アミノイソブタノール等のジアミン、アルコキシアミン又はアミノアルコールや、プロピルアミン、ブチルアミン、ペンチルアミン、ヘキシルアミン、ヘキシルアミン等のアルキルアミン（直鎖状アルキルアミン、側鎖を有していてもよい。）；シクロペンチルアミン、シクロヘキシルアミン等のシクロアルキルアミン；アニリン、アリルアミン等の第１級アミン；ジプロピルアミン、ジブチルアミン、ピペリジン、ヘキサメチレンイミン等の第２級アミン；トリプロピルアミン、ジメチルプロパンジアミン、シクロヘキシルジメチルアミン、ピリジン、キノリン等の第３級アミン等が挙げられる。なかでも、アルキルアミン、又は、アルコキシアミンが好ましい。 The amine may be linear or branched, and may have a side chain. Specifically, N- (3-methoxypropyl) propane-1,3-diamine, 1,2-ethanediamine, 2-methoxyethylamine, 3-methoxypropylamine, 3-ethoxypropylamine, 1,4-butane Diamine, diamine such as 1,5-pentanediamine, pentanolamine, aminoisobutanol, alkoxyamine or aminoalcohol, alkylamine such as propylamine, butylamine, pentylamine, hexylamine, hexylamine (linear alkylamine) A cycloalkylamine such as cyclopentylamine and cyclohexylamine; a primary amine such as aniline and allylamine; a second amine such as dipropylamine, dibutylamine, piperidine, and hexamethyleneimine. Secondary amine; tripropi Amine, dimethyl propanediamine, cyclohexyldimethylamine, pyridine, tertiary amines such as quinoline. Of these, alkylamines or alkoxyamines are preferred.
上記アミンは、例えば、ヒドロキシル基、カルボキシル基、アルコキシ基、カルボニル基、エステル基、メルカプト基等のアミン以外の官能基を含む化合物であってもよい。また、上記アミンは、単独で用いてもよく、２種以上を併用してもよい。上記アミンは、常圧での沸点が３００℃以下であることが好ましく、２５０℃以下であることがより好ましい。 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. Moreover, the said amine may be used independently and may use 2 or more types together. The amine preferably has a boiling point at normal pressure of 300 ° C. or lower, and more preferably 250 ° C. or lower.
本発明の効果を損なわない範囲であれは、上記のアミンに加えて、カルボン酸を含んでいてもよい。カルボン酸の一分子内におけるカルボキシル基が、比較的高い極性を有し、水素結合による相互作用を生じ易いが、これら官能基以外の部分は比較的低い極性を有する。更に、カルボキシル基は、酸性的性質を示し易い。 As long as the effects of the present invention are not impaired, a carboxylic acid may be included in addition to the above amine. The carboxyl group in one molecule of the carboxylic acid has a relatively high polarity and tends to cause an interaction due to a hydrogen bond, but a portion other than these functional groups has a relatively low polarity. Furthermore, the carboxyl group tends to exhibit acidic properties.
上記カルボン酸としては、少なくとも１つのカルボキシル基を有する化合物を広く用いることができ、例えば、ギ酸、シュウ酸、酢酸、ヘキサン酸、アクリル酸、オクチル酸、オレイン酸等が挙げられる。カルボン酸の一部のカルボキシル基が金属イオンと塩を形成していてもよい。なお、上記金属イオンについては、２種以上の金属イオンが含まれていてもよい。 As said carboxylic acid, the compound which has at least 1 carboxyl group can be used widely, For example, formic acid, oxalic acid, acetic acid, hexanoic acid, acrylic acid, octylic acid, oleic acid etc. are mentioned. A part of carboxyl groups of the carboxylic acid may form a salt with a metal ion. In addition, about the said metal ion, 2 or more types of metal ions may be contained.
上記カルボン酸は、例えば、アミノ基、ヒドロキシル基、アルコキシ基、カルボニル基、エステル基、メルカプト基等の、カルボキシル基以外の官能基を含む化合物であってもよい。この場合、カルボキシル基の数が、カルボキシル基以外の官能基の数以上であることが好ましい。また、上記カルボン酸は、それぞれ単独で用いてもよく、２種以上を併用してもよい。上記カルボン酸は、常圧での沸点が３００℃以下であることが好ましく、２５０℃以下であることがより好ましい。また、アミンとカルボン酸はアミド基を形成する。上記アミド基も銀微粒子表面に適度に吸着するため、有機成分にはアミド基が含まれていてもよい。 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. The carboxylic acid preferably has a boiling point at normal pressure of 300 ° C. or lower, and more preferably 250 ° C. or lower. Also, the amine and carboxylic acid form an amide group. Since the amide group also moderately adsorbs on the surface of the silver fine particles, the organic component may contain an amide group.
本発明のグラビアオフセット印刷用導電性ペーストにおける無機コロイド中の有機成分の含有量は、０．５～５０重量％であることが好ましい。有機成分含有量が０．５重量％以上であれば、得られる導電性ペーストの貯蔵安定性が良くなる傾向があり、５０重量％以下であれば、導電性パターンの導電性が良い傾向がある。有機成分のより好ましい含有量は１～３０重量％であり、更に好ましい含有量は２～１５重量％である。 The content of the organic component in the inorganic colloid in the conductive paste for gravure offset printing of the present invention is preferably 0.5 to 50% by weight. If the organic component content is 0.5% by weight or more, the storage stability of the resulting conductive paste tends to be improved, and if it is 50% by weight or less, the conductivity of the conductive pattern tends to be good. . A more preferable content of the organic component is 1 to 30% by weight, and a more preferable content is 2 to 15% by weight.
上記アミンと上記カルボン酸とを併用する場合、上記アミンと上記カルボン酸との組成比（重量）は、１／９９～９９／１の範囲で任意に選択することができる。好ましくは、上記アミンと上記カルボン酸との組成比が２０／８０～９８／２であり、更に好ましくは３０／７０～９７／３である。なお、上記アミン又は上記カルボン酸は、それぞれ複数種類のアミン又はカルボン酸を用いてもよい。 When the amine and the carboxylic acid are used in combination, the composition ratio (weight) of the amine and the carboxylic acid can be arbitrarily selected within the range of 1/99 to 99/1. Preferably, the composition ratio of the amine to the carboxylic acid is 20/80 to 98/2, and more preferably 30/70 to 97/3. In addition, you may use multiple types of amine or carboxylic acid for the said amine or said carboxylic acid, respectively.
（有機溶媒）
本発明のグラビアオフセット印刷用導電性ペーストは、銀微粒子の分散媒として有機溶媒を含有する。分散媒として有機溶媒を用いることで、銀微粒子の凝集を抑制できる。また、一般的に沸点が高く乾燥し難いことから、ブランケットへの転写がしやすい。また、表面張力が低いことから、ブランケットとして一般的に用いられるシリコーンゴムとの馴染みもよい。なお、分散媒として水を用いた場合には、銀微粒子が凝集し、グラビア版の凹部に詰まるおそれがある。また、水は、表面張力が高くブランケットに対する濡れ性が悪い、沸点が低く乾燥しやすい等の理由から、転写工程を有するグラビアオフセット印刷用に用いる導電性ペーストの分散媒としては不向きである。 (Organic solvent)
The conductive paste for gravure offset printing of the present invention contains an organic solvent as a dispersion medium for silver fine particles. Aggregation of silver fine particles can be suppressed by using an organic solvent as a dispersion medium. Moreover, since it generally has a high boiling point and is difficult to dry, it can be easily transferred to a blanket. In addition, since the surface tension is low, familiarity with silicone rubber generally used as a blanket is good. When water is used as the dispersion medium, silver fine particles may aggregate and clog the concave portions of the gravure plate. Further, water is not suitable as a dispersion medium for conductive paste used for gravure offset printing having a transfer process because of high surface tension, poor wettability to a blanket, low boiling point, and easy drying.
上記有機溶媒は、ヒドロキシル基を含有し、常圧での沸点が２００℃以上である第１の有機溶媒を含有することが好ましい。本発明のグラビアオフセット印刷用導電性ペーストは、線幅が１０μｍ以下、特に線幅が３μｍ以下の細線印刷に好適に用いられることから、乾燥し難い溶媒を用いることが好ましい。上記第１の有機溶媒の常圧での沸点が２００℃以上であることで、グラビア版上で上記導電性ペーストが過度に乾燥することを抑制できる。また、上記第１の有機溶媒がヒドロキシル基を含有することで、銀微粒子の分散が良好になり、かつ、有機溶媒の極性が上がることでブランケットの膨潤が抑制される傾向となる。 The organic solvent preferably contains a first organic solvent containing a hydroxyl group and having a boiling point of 200 ° C. or higher at normal pressure. Since the conductive paste for gravure offset printing of the present invention is suitably used for fine line printing with a line width of 10 μm or less, particularly 3 μm or less, it is preferable to use a solvent that is difficult to dry. When the boiling point of the first organic solvent at normal pressure is 200 ° C. or higher, the conductive paste can be prevented from being excessively dried on the gravure plate. In addition, when the first organic solvent contains a hydroxyl group, the dispersion of the silver fine particles becomes good, and the polarity of the organic solvent increases, so that the swelling of the blanket tends to be suppressed.
上記第１の有機溶媒としては、例えば、２，４－ジエチル－１，５－ペンタンジオール、３－メチル－１，５－ペンタンジオール、２－エチル－１，３－ヘキサンジオール、トリプロピレングリコール、トリエチレングリコール、１，２－ヘキサンジオール、１．３ブチレングリコール、１，３－プロパンジオール、ジプロピレングリコール、２－ブテン－１，４－ジオール等のジオール溶媒を用いることが好ましい。 Examples of the first organic solvent include 2,4-diethyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, tripropylene glycol, It is preferable to use a diol solvent such as triethylene glycol, 1,2-hexanediol, 1.3 butylene glycol, 1,3-propanediol, dipropylene glycol, 2-butene-1,4-diol.
上記導電性ペースト全体に対する上記第１の有機溶媒の含有率は、３～３０重量％であることが好ましい。上記第１の有機溶媒の含有率のより好ましい上限は２５重量％、更に好ましい上限は２０重量％である。 The content of the first organic solvent in the entire conductive paste is preferably 3 to 30% by weight. A more preferred upper limit for the content of the first organic solvent is 25% by weight, and a more preferred upper limit is 20% by weight.
上記有機溶媒は、ブランケット膨潤率が２．０％以下の第２の有機溶媒を３．０～３０重量％含有することが好ましい。上記ブランケット膨潤率が２．０％以下の第２の有機溶媒を、「低膨潤性有機溶媒」ともいう。上記第２の有機溶媒は、上記第１の有機溶媒を兼ねてもよい。上記ブランケット膨潤率が２．０％以下と極めて低い低膨潤性有機溶媒を用いることで、ブランケットへの有機溶媒の吸収を低減でき、ブランケット表面での導電性ペーストの乾燥を大幅に抑制することができる。導電性ペーストを用いて細線を印刷する場合、細線状に印刷された導電性ペーストが非常に乾燥しやすく、良好な導電性パターンを形成することが困難である。これに対し、有機溶媒のブランケット膨潤率を２．０％以下にすることで、例えば、線幅が３μｍ以下の細線導電性パターンの形成にも対応することができる。なお、より好ましいブランケット膨潤率は０．４％以下である。 The organic solvent preferably contains 3.0 to 30% by weight of a second organic solvent having a blanket swelling rate of 2.0% or less. The second organic solvent having a blanket swelling ratio of 2.0% or less is also referred to as a “low swelling organic solvent”. The second organic solvent may also serve as the first organic solvent. By using a low swellable organic solvent with a blanket swelling rate of 2.0% or less, the absorption of the organic solvent into the blanket can be reduced, and the drying of the conductive paste on the blanket surface can be greatly suppressed. it can. When printing a thin line using a conductive paste, the conductive paste printed in a thin line shape is very easy to dry, and it is difficult to form a good conductive pattern. On the other hand, by setting the blanket swelling ratio of the organic solvent to 2.0% or less, for example, it is possible to cope with the formation of a thin wire conductive pattern having a line width of 3 μm or less. A more preferable blanket swelling ratio is 0.4% or less.
また、導電性ペースト全体に対する上記第２の有機溶媒の含有率を３．０重量％以上とすることで、上記導電性ペーストに適当な塗布性（流動性）を付与することができ、更に、例えば、線幅が３μｍ以下のような細線印刷時の乾燥を抑制することができる。上記含有率を３０重量％以下とすることで、印刷時の拡がりを防ぐことができる。なお、低膨潤性有機溶媒の含有率のより好ましい上限は２５．０重量％、更に好ましい上限は２０．０重量％である。 Further, by setting the content ratio of the second organic solvent to the entire conductive paste to be 3.0% by weight or more, it is possible to impart appropriate coating properties (fluidity) to the conductive paste, For example, drying at the time of fine line printing with a line width of 3 μm or less can be suppressed. By setting the content to 30% by weight or less, it is possible to prevent the spread during printing. In addition, the more preferable upper limit of the content of the low swelling organic solvent is 25.0% by weight, and the more preferable upper limit is 20.0% by weight.
一般的にグラビアオフセット印刷に用いる印刷版の最表面はシリコーンゴム製であり、本発明における「ブランケット膨潤率」とは、シリコーンゴムを有機溶媒に浸漬させた際の膨潤率を意味する。ここで、「ブランケット膨潤率」は、有機溶媒中にブランケット（シリコーンゴム）を浸漬させた際の、上記浸漬前後におけるブランケット（シリコーンゴム）の重量変化率と同意である。具体的には、ブランケット（シリコーンゴム）を１ｃｍ角に切り出して試験片とし、上記試験片を有機溶媒に室温条件下（２５℃±５℃）で浸漬させ、１０時間後に取り出して浸漬前後における重量増加率を求めることで、「ブランケット膨潤率」を評価することができる。導電性ペースト印刷用に標準的に用いられているシリコーンブランケットであれば、特定の有機溶媒に対して測定される膨潤率に大きな差は無いことが実験的に証明されている。 Generally, the outermost surface of a printing plate used for gravure offset printing is made of silicone rubber, and the “blanket swelling ratio” in the present invention means a swelling ratio when silicone rubber is immersed in an organic solvent. Here, “the blanket swelling rate” is the same as the weight change rate of the blanket (silicone rubber) before and after the immersion when the blanket (silicone rubber) is immersed in an organic solvent. Specifically, a blanket (silicone rubber) is cut into a 1 cm square to obtain a test piece, and the test piece is immersed in an organic solvent under room temperature conditions (25 ° C. ± 5 ° C.), taken out after 10 hours, and weight before and after immersion. By obtaining the increase rate, the “blanket swelling rate” can be evaluated. It has been experimentally proved that there is no significant difference in the swelling rate measured for a specific organic solvent in the case of a silicone blanket that is used as a standard for conductive paste printing.
ブランケット膨潤率が２．０％以下となる低膨潤性有機溶媒としては、本発明の効果を損なわない限りにおいて、種々の溶媒を使用することができる。なかでも、官能基としてヒドロキシル基を有する溶媒が好ましく、例えば、ヒドロキシル基を複数有する多価アルコールや、その他１価のアルコール溶媒等が挙げられる。また、ブランケット膨潤率が極めて低いジオールのような極性の高い溶媒を用いることで、ブランケット上での細線パターンの乾燥をより効果的に抑制することができる。これらの溶媒は、それぞれ単独で用いてもよく、２種以上を併用してもよい。 As the low-swelling organic solvent having a blanket swelling rate of 2.0% or less, various solvents can be used as long as the effects of the present invention are not impaired. Especially, the solvent which has a hydroxyl group as a functional group is preferable, for example, the polyhydric alcohol which has two or more hydroxyl groups, other monohydric alcohol solvents, etc. are mentioned. Further, by using a highly polar solvent such as a diol having a very low blanket swelling rate, drying of the fine line pattern on the blanket can be more effectively suppressed. These solvents may be used alone or in combination of two or more.
（ブランケット膨潤率が２．０％以下の有機溶媒）
上記ヒドロキシル基を２～３有している多価アルコールとしては、グリセリン、１，２，４－ブタントリオール、１，２，６－ヘキサントリオール、エチレングリコール、ジエチレングリコール、１，２－ブタンジオール、プロピレングリコール、２－メチルペンタン－２，４－ジオール等が挙げられる。 (Organic solvent with a blanket swelling ratio of 2.0% or less)
Examples of the polyhydric alcohol having 2 to 3 hydroxyl groups include glycerin, 1,2,4-butanetriol, 1,2,6-hexanetriol, ethylene glycol, diethylene glycol, 1,2-butanediol, propylene Glycol, 2-methylpentane-2,4-diol and the like.
上記１価のアルコールとしては、ブチルトリグリコール、イソブチルジグリコール、２－ブトキシエタノール、３－メトキシ－３－メチルブタノール、２－（２－メトキシエトキシ）エタノール、２－（２－ヘキシルオキシエトキシ）エタノール等が挙げられる。 Examples of the monohydric alcohol include butyl triglycol, isobutyl diglycol, 2-butoxyethanol, 3-methoxy-3-methylbutanol, 2- (2-methoxyethoxy) ethanol, 2- (2-hexyloxyethoxy) ethanol Etc.
また、上記第１の有機溶媒と重複するが、２，４－ジエチル－１，５－ペンタンジオール、３－メチル－１，５－ペンタンジオール、２－エチル－１，３－ヘキサンジオール、トリプロピレングリコール、トリエチレングリコール、１，２－ヘキサンジオール、１．３ブチレングリコール、１，３－プロパンジオール、ジプロピレングリコール、２－ブテン－１，４－ジオール等のジオール溶媒を用いてもよい。 Further, although overlapping with the first organic solvent, 2,4-diethyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, tripropylene Diol solvents such as glycol, triethylene glycol, 1,2-hexanediol, 1.3 butylene glycol, 1,3-propanediol, dipropylene glycol, and 2-butene-1,4-diol may be used.
上記有機溶媒は、本発明の効果を損なわない範囲で、種々のものを使用可能であり、上記第１の有機溶媒及び上記第２の有機溶媒の他に、乾燥性の調整等でブランケット膨潤率２．０％を超える膨潤率が高い溶媒を混合して用いてもよい。なお、混合する溶媒の数及び組合せは特に限定されない。 Various organic solvents can be used as long as the effects of the present invention are not impaired. In addition to the first organic solvent and the second organic solvent, the blanket swelling rate can be adjusted by adjusting the drying property. A solvent having a high swelling ratio exceeding 2.0% may be mixed and used. The number and combination of solvents to be mixed are not particularly limited.
（ブランケット膨潤率が２．０％を超える有機溶媒）
ブランケット膨潤率が２．０％を超える有機溶媒としては、グリコールエーテル、グリコールエステル、テルペン系溶媒、炭化水素溶媒、アルコール溶媒等が挙げられる。これらの溶媒は、単独で用いてもよく、２種以上を併用してもよい。なお、上記有機溶媒でのテルペン溶媒の濃度が高過ぎると、ブランケットに吸収される溶媒量が多くなり、転写印刷途中のブランケット上で乾燥が進みやすいことから、ジオール溶媒とテルペン系溶媒をバランスよく配合することが好ましい。 (Organic solvent with blanket swelling rate exceeding 2.0%)
Examples of the organic solvent having a blanket swelling rate exceeding 2.0% include glycol ethers, glycol esters, terpene solvents, hydrocarbon solvents, alcohol solvents, and the like. These solvents may be used alone or in combination of two or more. If the concentration of the terpene solvent in the organic solvent is too high, the amount of solvent absorbed by the blanket increases, and drying tends to proceed on the blanket during transfer printing.Therefore, the diol solvent and the terpene solvent are balanced. It is preferable to mix.
上記ブランケット膨潤率が２．０％を超える有機溶媒の具体例としては、例えば、トリプロピレングリコール－ｎ－ブチルエーテル、ブチルカルビトール、ジエチレングリコールモノメチルエーテル、トリプロピレングリコールメチルエーテル、ジエチレングリコールモノエチルエーテルアセテート、ジエチレングリコールモノブチルエーテルアセテート、トリエチレングリコールジメチルエーテル、ジプロピレングリコールメチルエーテルアセテート、エチレングリコールモノヘキシルエーテル、ジプロピレングリコールメチルエーテル、プロピレングリコールジアセテート、１，４－ブタンジオールジビニルエーテル、エチレングリコールモノブチルエーテル、エチレングリコールモノメチルエーテルアセテート等が挙げられる。 Specific examples of the organic solvent having a blanket swelling rate exceeding 2.0% include, for example, tripropylene glycol-n-butyl ether, butyl carbitol, diethylene glycol monomethyl ether, tripropylene glycol methyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol. Monobutyl ether acetate, triethylene glycol dimethyl ether, dipropylene glycol methyl ether acetate, ethylene glycol monohexyl ether, dipropylene glycol methyl ether, propylene glycol diacetate, 1,4-butanediol divinyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl Examples include ether acetate.
上記炭化水素溶媒は、脂肪族炭化水素化合物を含有するものであってもよく、環状炭化水素化合物を含有するものであってもよく、脂環式炭化水素化合物を含有するものであってもよい。 The hydrocarbon solvent may contain an aliphatic hydrocarbon compound, may contain a cyclic hydrocarbon compound, or may contain an alicyclic hydrocarbon compound. .
上記脂肪族炭化水素化合物としては、例えば、テトラデカン、オクタデカン、ヘプタメチルノナン、テトラメチルペンタデカン、ヘキサン、ヘプタン、オクタン、ノナン、デカン、トリデカン、メチルペンタン、ノルマルパラフィン、イソパラフィン等の飽和又は不飽和脂肪族炭化水素化合物を挙げることができる。 Examples of the aliphatic hydrocarbon compounds include saturated or unsaturated aliphatic compounds such as tetradecane, octadecane, heptamethylnonane, tetramethylpentadecane, hexane, heptane, octane, nonane, decane, tridecane, methylpentane, normal paraffin, and isoparaffin. There may be mentioned hydrocarbon compounds.
上記環状炭化水素化合物としては、例えば、トルエン、キシレン等が挙げられる。 Examples of the cyclic hydrocarbon compound include toluene, xylene and the like.
上記脂環式炭化水素化合物としては、例えば、リモネン、ジペンテン、テルピネン、ターピネン（テルピネンともいう。）、ネソール、シネン、オレンジフレーバー、テルピノレン、ターピノレン（テルピノレンともいう。）、フェランドレン、メンタジエン、テレベン、ジヒドロサイメン、モスレン、イソテルピネン、イソターピネン（イソテルピネンともいう。）、クリトメン、カウツシン、カジェプテン、オイリメン、ピネン、テレビン、メンタン、ピナン、テルペン、シクロヘキサン等が挙げられる。 Examples of the alicyclic hydrocarbon compound include limonene, dipentene, terpinene, terpinene (also referred to as terpinene), nesol, sinene, orange flavor, terpinolene, terpinolene (also referred to as terpinolene), ferrandrene, mentadiene, teleben, Examples thereof include dihydrocymene, moslen, isoterpinene, isoterpinene (also referred to as isoterpinene), clitomen, kautssin, cajeptene, oilimene, pinene, turpentine, menthane, pinane, terpene, and cyclohexane.
上記アルコール溶媒は、ヒドロキシル基を分子構造中に１つ以上含む化合物であり、脂肪族アルコール、環状アルコール及び脂環式アルコールが挙げられる。これらのアルコールは、単独で用いてもよく、２種以上を併用してもよい。また、ヒドロキシル基の一部は、本発明の効果を損なわない範囲でアセトキシ基等に誘導されていてもよい。 The alcohol solvent is a compound containing one or more hydroxyl groups in the molecular structure, and examples thereof include aliphatic alcohols, cyclic alcohols, and alicyclic alcohols. These alcohols may be used alone or in combination of two or more. Moreover, a part of hydroxyl group may be induced | guided | derived to the acetoxy group etc. in the range which does not impair the effect of this invention.
上記脂肪族アルコールとしては、例えば、ヘプタノール、オクタノール（１－オクタノール、２－オクタノール、３－オクタノール等）、デカノール（１－デカノール等）、ラウリルアルコール、テトラデシルアルコール、セチルアルコール、２－エチル－１－ヘキサノール、オクタデシルアルコール、ヘキサデセノール、オレイルアルコール等の飽和又は不飽和の炭素数６～３０の脂肪族アルコール等が挙げられる。 Examples of the aliphatic alcohol include heptanol, octanol (1-octanol, 2-octanol, 3-octanol, etc.), decanol (1-decanol, etc.), lauryl alcohol, tetradecyl alcohol, cetyl alcohol, 2-ethyl-1 -Saturated or unsaturated aliphatic alcohols having 6 to 30 carbon atoms such as hexanol, octadecyl alcohol, hexadecenol and oleyl alcohol.
上記環状アルコールとしては、例えば、クレゾール、オイゲノール等が挙げられる。 Examples of the cyclic alcohol include cresol and eugenol.
上記脂環式アルコールとしては、例えば、シクロヘキサノール等のシクロアルカノール、ターピネオール（テルピネオール、α、β、γ異性体、又はこれらの任意の混合物を含む。）、ジヒドロテルピネオール等のテルペンアルコール（モノテルペンアルコール等）、ジヒドロターピネオール、ミルテノール、ソブレロール、メントール、カルベオール、ペリリルアルコール、ピノカルベオール、ソブレロール、ベルベノール等が挙げられる。上記脂環式アルコールは、上記テルペン溶媒と重複してもよい。 Examples of the alicyclic alcohol include cycloalkanols such as cyclohexanol, terpineol (including terpineol, α, β, γ isomers, or any mixture thereof), and terpene alcohols such as dihydroterpineol (monoterpene alcohols). Etc.), dihydroterpineol, myrtenol, sobrerol, menthol, carveol, perillyl alcohol, pinocarveol, sobrerol, berbenol and the like. The alicyclic alcohol may overlap with the terpene solvent.
（水溶性高分子）
本発明のグラビアオフセット印刷用導電性ペーストは、水溶性高分子を含有する。水溶性高分子を含有することで、ブランケット及び被着体界面への吸着作用が高まるため、グラビアオフセット印刷法を用いて、例えば線幅が３μｍ以下の導電性パターンであっても断線することなく形成することができる。本明細書中、「水溶性」とは、水１Ｌに対して１ｇ以上の溶解性を有するものをいう。 (Water-soluble polymer)
The conductive paste for gravure offset printing of the present invention contains a water-soluble polymer. By containing a water-soluble polymer, the adsorption action to the blanket and adherend interface is enhanced, so that even if the conductive pattern has a line width of 3 μm or less, for example, without breaking, using the gravure offset printing method Can be formed. In the present specification, “water-soluble” means one having a solubility of 1 g or more with respect to 1 L of water.
上記水溶性高分子は、有機溶媒にも水にも可溶な高分子であることが好ましい。更に、上記水溶性高分子は、基材への密着性、基材への転写性、ブランケット上での線の広がりが起き難いことが求められる。上記導電性ペーストの被着体（基材）が、例えば、ポリエチレンテレフタレート（ＰＥＴ）である場合、ＰＥＴへの密着性が良好であるものが好ましい。 The water-soluble polymer is preferably a polymer that is soluble in both an organic solvent and water. Furthermore, the water-soluble polymer is required to have no adhesiveness to the substrate, transferability to the substrate, and difficulty in spreading the line on the blanket. When the adherend (base material) of the conductive paste is, for example, polyethylene terephthalate (PET), one having good adhesion to PET is preferable.
上記水溶性高分子は、環状構造を有する重合性化合物を含有することが好ましい。有機溶媒への溶解性は限定的だが、ポリビニルアルコールも用いることができる。上記環状構造は、γ－ラクタムであることが好ましく、また、ビニル基を有することが好ましい。なかでも、上記水溶性高分子は、ポリビニルピロリドンを含有することがより好ましい。ポリビニルピロリドンは、下記化学式（１）で表される高分子である。 The water-soluble polymer preferably contains a polymerizable compound having a cyclic structure. Although solubility in organic solvents is limited, polyvinyl alcohol can also be used. The cyclic structure is preferably γ-lactam and preferably has a vinyl group. Especially, it is more preferable that the water-soluble polymer contains polyvinyl pyrrolidone. Polyvinylpyrrolidone is a polymer represented by the following chemical formula (1).
Figure JPOXMLDOC01-appb-C000001
 （式中、ｎは自然数である。）
Figure JPOXMLDOC01-appb-C000001
 (In the formula, n is a natural number.)
ポリビニルピロリドンは、極性の高い多価アルコール（特にジオール溶媒）への溶解性が高く、エステル、ケトン等の溶媒にも良好に溶解可能であるため、これらの有機溶媒に対して銀微粒子を良好に分散することができる。特にヒドロキシル基を含有し、常圧での沸点が２００℃以上である第１の有機溶媒に良好に溶解する。 Polyvinylpyrrolidone is highly soluble in highly polar polyhydric alcohols (especially diol solvents) and can be dissolved well in solvents such as esters and ketones. Can be dispersed. In particular, it dissolves well in a first organic solvent containing a hydroxyl group and having a boiling point of 200 ° C. or higher at normal pressure.
また、ポリビニルピロリドンは、水にも可溶であるため、基材界面への吸着作用を顕著に高めることができる。更に、グラビアオフセット印刷の特徴として、半固体／半液体状のペーストをブランケット上で転写印刷するが、ポリビニルピロリドンは半固体／半液体状態で非常に高いタック性（粘着性）を有しているため、ブランケットから基材への転写に非常に優れている。そのため、従来の導電性ペーストでは印刷できなかった、線幅が例えば３μｍ以下の細線印刷における印刷性を格段に向上させることができる。 Further, since polyvinyl pyrrolidone is soluble in water, the adsorption action on the substrate interface can be remarkably enhanced. Furthermore, as a feature of gravure offset printing, a semi-solid / semi-liquid paste is transferred and printed on a blanket. Polyvinylpyrrolidone has a very high tack (adhesiveness) in a semi-solid / semi-liquid state. Therefore, it is very excellent in transferring from a blanket to a substrate. Therefore, the printability in thin line printing with a line width of, for example, 3 μm or less, which could not be printed with a conventional conductive paste, can be significantly improved.
上記ポリビニルピロリドンは、平均分子量が１０万以下であることが好ましい。平均分子量が１０万以下であることで、過度に導電性ペーストの粘度を上げず、かつ、ブランケットや基材への転写性を良好なものとすることができる。このようなポリビニルピロリドンとしては、ポリビニルピロリドンＫ２５（平均分子量：２５０００）、ポリビニルピロリドンＫ３０（平均分子量：４００００）（ともに、和光純薬工業社製）等が挙げられる。上記平均分子量は、重量平均分子量であり、液体クロマトグラフィーにより測定したものである。上記重量平均分子量の測定には、島津製作所社製のＬＣ－６ＡＤ　ｐｕｍｐ、ＲＩＤ－１０Ａ　ＲＩ　ｄｅｔｅｃｔｏｒ、ＣＬＡＳＳ－ＬＣ１０　Ｃｈｒｏｍａｔｏｐａｃ　ｄａｔａ　ｐｒｏｃｅｓｓｏｒ、及び、ＤＧＵ－２０Ａ３　ｄｅｇａｓｓｅｒを使用する。また、カラムとして、ＴＳＫ－ＧＥＬ　Ｇ１０００Ｈ、Ｇ２０００Ｈ及びＧ２５００Ｈを用い、オーブン温度を４０℃としてテトラヒドロフラン（ＴＨＦ）を流速１．０ｍＬ／分で流す。上記重量平均分子量は、ポリスチレンを標準としてキャリブレーションすることで算出する。 The polyvinyl pyrrolidone preferably has an average molecular weight of 100,000 or less. When the average molecular weight is 100,000 or less, the viscosity of the conductive paste is not excessively increased, and transferability to a blanket or a substrate can be improved. Examples of such polyvinyl pyrrolidone include polyvinyl pyrrolidone K25 (average molecular weight: 25000), polyvinyl pyrrolidone K30 (average molecular weight: 40000) (both manufactured by Wako Pure Chemical Industries, Ltd.) and the like. The average molecular weight is a weight average molecular weight and is measured by liquid chromatography. For the measurement of the weight average molecular weight, LC-6AD pump, RID-10A RI detector, CLASS-LC10 Chromatopac data processor, and DGU-20A3 degasser manufactured by Shimadzu Corporation are used. In addition, TSK-GEL G1000H, G2000H, and G2500H are used as columns, and the oven temperature is set to 40 ° C., and tetrahydrofuran (THF) is allowed to flow at a flow rate of 1.0 mL / min. The weight average molecular weight is calculated by calibration using polystyrene as a standard.
上記水溶性高分子の含有量は、上記導電性ペースト全体に対して、３～８重量％であることが好ましい。上記水溶性高分子の含有量が３重量％未満では、被着体への粘着性が低下することがある。一方、上記水溶性高分子の含有量が８重量％を超えると、本発明の導電性ペーストにより形成される導電性パターンの体積抵抗値が上昇することがある。上記水溶性高分子の含有量のより好ましい上限は７重量％である。 The content of the water-soluble polymer is preferably 3 to 8% by weight with respect to the entire conductive paste. When the content of the water-soluble polymer is less than 3% by weight, the adhesion to the adherend may be lowered. On the other hand, when the content of the water-soluble polymer exceeds 8% by weight, the volume resistance value of the conductive pattern formed by the conductive paste of the present invention may increase. The upper limit with more preferable content of the said water-soluble polymer is 7 weight%.
本発明のグラビアオフセット印刷用導電性ペーストには、上記の成分に加えて、本発明の効果を損なわない範囲で、使用目的に応じた適度な粘性、密着性、乾燥性又は印刷性等の機能を付与するために、高分子分散剤、オリゴマー成分、界面活性剤、増粘剤又は表面張力調整剤等の任意成分を添加してもよい。かかる任意成分としては、特に限定されない。 In the conductive paste for gravure offset printing of the present invention, in addition to the above components, functions such as appropriate viscosity, adhesion, drying property or printability according to the purpose of use within the range not impairing the effects of the present invention. In order to impart, an optional component such as a polymer dispersant, an oligomer component, a surfactant, a thickener, or a surface tension adjuster may be added. Such optional components are not particularly limited.
上記高分子分散剤としては、市販されている高分子分散剤を使用することができる。市販の高分子分散剤としては、例えば、ソルスパース（ＳＯＬＳＰＥＲＳＥ）１１２００、ソルスパース１３９４０、ソルスパース１６０００、ソルスパース１７０００、ソルスパース１８０００、ソルスパース２００００、ソルスパース２４０００、ソルスパース２６０００、ソルスパース２７０００、ソルスパース２８０００（日本ルーブリゾール社製）；ＤＩＳＰＥＲＢＹＫ－１０２、１１０、１１１、１７０、１９０．１９４Ｎ、２０１５、２０９０、２０９６（ビックケミー・ジャパン社製）；ＥＦＫＡ－４６、ＥＦＫＡ－４７、ＥＦＫＡ－４８、ＥＦＫＡ－４９（ＥＦＫＡケミカル社製）；ポリマー１００、ポリマー１２０、ポリマー１５０、ポリマー４００、ポリマー４０１、ポリマー４０２、ポリマー４０３、ポリマー４５０、ポリマー４５１、ポリマー４５２、ポリマー４５３（ＥＦＫＡケミカル社製）；アジスパーＰＢ７１１、アジスパーＰＡ１１１、アジスパーＰＢ８１１、アジスパーＰＷ９１１（味の素社製）；フローレンＤＯＰＡ－１５Ｂ、フローレンＤＯＰＡ－２２、フローレンＤＯＰＡ－１７、フローレンＴＧ－７３０Ｗ、フローレンＧ－７００、フローレンＴＧ－７２０Ｗ（共栄社化学工業社製）、ビックケミー社製ＤＩＳＰＥＲＢＹＫシリーズ等が挙げられ、エボニック社製のＴＥＧＯ　Ｄｉｓｐｅｒｓシリーズでは６１０、６１０Ｓ、６３０、６５１、６５５、７５０Ｗ、７５５Ｗ等が挙げられ、楠本化成社製のディスパロンシリーズではＤＡ－３７５、ＤＡ－１２００等が挙げられ、低温焼結性及び分散安定性の観点からは、ＤＩＳＰＥＲＢＹＫ－１０２、ソルスパース１１２００、ソルスパース１３９４０、ソルスパース１６０００、ソルスパース１７０００、ソルスパース１８０００、ソルスパース２８０００等を用いることが好ましい。 A commercially available polymer dispersant can be used as the polymer dispersant. Examples of the commercially available polymer dispersing agent include Solsperse 11200, Solsperse 13940, Solsperse 16000, Solsperse 17000, Solsperse 18000, Solsperse 20000, Solsperse 24000, Solsperse 26000, Solsperse 27000, Solsperse 28000 (manufactured by Nippon Lubrizol) DISPERBYK-102, 110, 111, 170, 190.194N, 2015, 2090, 2096 (manufactured by Big Chemie Japan); EFKA-46, EFKA-47, EFKA-48, EFKA-49 (manufactured by EFKA Chemical); Polymer 100, Polymer 120, Polymer 150, Polymer 400, Polymer 401, Polymer 402, Polymer 403, Polymer 45 , Polymer 451, polymer 452, polymer 453 (manufactured by EFKA Chemical Co.); Ajisper PB711, Ajisper PA111, Ajisper PB811, Ajisper PW911 (manufactured by Ajinomoto Co.); Florene DOPA-15B, Florene DOPA-22, Florene DOPA-17, Florene TG -730W, Floren G-700, Floren TG-720W (manufactured by Kyoeisha Chemical Industry Co., Ltd.), DISPERBYK series manufactured by BYK Chemie Co., etc., and the TEGO Dispers series manufactured by Evonik Co., 755W and the like, and the Disparon series manufactured by Enomoto Kasei Co., Ltd. include DA-375 and DA-1200. From the viewpoint of low temperature sinterability and dispersion stability, DISPER YK-102, Solsperse 11200, Solsperse 13940, Solsperse 16000, Solsperse 17000, Solsperse 18000, it is preferable to use Solsperse 28000 and the like.
上記高分子分散剤の含有量は、導電性ペースト全体に対して、０．１～１５重量％であることが好ましい。導電性ペースト全体に対する上記高分子分散剤の含有量が０．１重量％以上であれば、得られる導電性ペーストの分散安定性が良くなるが、含有量が多過ぎる場合は分散安定性が低下することとなる。このような観点から、高分子分散剤のより好ましい含有量は０．３～３重量％であり、更に好ましい含有量は０．５～２重量％である。 The content of the polymer dispersant is preferably 0.1 to 15% by weight with respect to the entire conductive paste. If the content of the polymer dispersant is 0.1% by weight or more with respect to the entire conductive paste, the dispersion stability of the resulting conductive paste is improved, but if the content is too large, the dispersion stability is lowered. Will be. From such a viewpoint, the more preferable content of the polymer dispersant is 0.3 to 3% by weight, and the more preferable content is 0.5 to 2% by weight.
上記増粘剤としては、例えば、クレイ、ベントナイト又はヘクトライト等の粘土鉱物；ポリエステル系エマルジョン樹脂、アクリル系エマルジョン樹脂、ポリウレタン系エマルジョン樹脂又はブロックドイソシアネート等のエマルジョン；メチルセルロース、カルボキシメチルセルロース、ヒドロキシエチルセルロース、ヒドロキシプロピルセルロース、ヒドロキシプロピルメチルセルロース等のセルロース誘導体；キサンタンガム又はグアーガム等の多糖類等が挙げられ、これらはそれぞれ単独で用いてもよく、２種以上を併用してもよい。 Examples of the thickener include clay minerals such as clay, bentonite or hectorite; emulsions such as polyester emulsion resins, acrylic emulsion resins, polyurethane emulsion resins or blocked isocyanates; 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.
上記有機成分の他に、更に界面活性剤を添加してもよい。多成分溶媒系の無機コロイド分散液においては、乾燥時の揮発速度の違いによる被膜表面の荒れ及び固形分の偏りが生じ易い。本実施形態の導電性ペーストに界面活性剤を添加することによって、これらの不利益を抑制し、均一な導電性被膜を形成することができる。 In addition to the organic component, a surfactant may be further added. In a multi-component solvent-based inorganic colloidal dispersion, the coating surface becomes rough and the solid content tends to be uneven due to the difference in volatilization rate during drying. By adding a surfactant to the conductive paste of the present embodiment, these disadvantages can be suppressed and a uniform conductive film can be formed.
上記界面活性剤としては、特に限定されず、アニオン性界面活性剤、カチオン性界面活性剤、ノニオン性界面活性剤等を用いることができる。具体的には、アルキルベンゼンスルホン酸塩、４級アンモニウム塩等が挙げられる。少量の添加量で効果が得られる観点からは、フッ素系界面活性剤がより好ましい。 The surfactant is not particularly limited, and an anionic surfactant, a cationic surfactant, a nonionic surfactant, and the like can be used. Specific examples include alkyl benzene sulfonate and quaternary ammonium salts. From the viewpoint of obtaining an effect with a small addition amount, a fluorine-based surfactant is more preferable.
上記導電性ペーストの粘度は、５００ｃＰ～１００００ｃＰであることが好ましい。上記導電性ペーストの粘度が上記範囲であると、グラビア版の凹部に充填しやすく、また、被着体への転写後に導電性ペーストがにじみにくいため、細線印刷が可能である。上記粘度は、コーンプレート型粘度計（例えばアントンパール社製のレオメーターＭＣＲ３０１）により測定可能である。測定は温度２５℃で行い、コーン回転数５０ｒｐｍにおける粘度を採用できる。上記粘度は、せん断粘度で表すこともでき、シェアレート１ｓ－１でのペースト粘度が０．５～２０Ｐａ・ｓであることが好ましい。また、シェアレート１ｓ－１でのペースト粘度が１０Ｐａ・ｓ以下、かつシェアレート１００ｓ－１でのペースト粘度が０．５Ｐａ・ｓ以上であることがより好ましい。 The viscosity of the conductive paste is preferably 500 cP to 10,000 cP. When the viscosity of the conductive paste is within the above range, the concave portions of the gravure plate can be easily filled, and the conductive paste is difficult to bleed after transfer to the adherend, so that fine line printing is possible. The viscosity can be measured with a cone plate viscometer (for example, a rheometer MCR301 manufactured by Anton Paar). The measurement is performed at a temperature of 25 ° C., and the viscosity at a cone rotation speed of 50 rpm can be adopted. The viscosity can also be expressed as a shear viscosity, and the paste viscosity at a shear rate of 1 s −1 is preferably 0.5 to 20 Pa · s. More preferably, the paste viscosity at a share rate of 1 s −1 is 10 Pa · s or less, and the paste viscosity at a share rate of 100 s −1 is 0.5 Pa · s or more.
なお、導電性パターンの印刷には、一般的にスクリーン印刷も用いられるが、スクリーン印刷は孔版印刷であるため、粘度が低ければペーストが流れてしまいパターン通りの印刷が困難となるため、グラビアオフセット印刷用よりも高粘度の導電性ペーストが用いられる。一般的にスクリーン印刷に用いられる導電性ペーストは、５００００～１０００００ｃＰ程度の粘度範囲のものが多い。仮に、スクリーン印刷用の導電性ペーストをグラビアオフセット印刷のグラビア版に充填すると、粘度が高すぎてブランケットへの転写が困難であるとともに、グラビア版の凹部に詰まりが発生する。 Screen printing is also generally used for printing conductive patterns, but screen printing is stencil printing, so if the viscosity is low, paste will flow and it will be difficult to print according to the pattern. A conductive paste having a higher viscosity than that for printing is used. In general, many conductive pastes used for screen printing have a viscosity range of about 50,000 to 100,000 cP. If a gravure plate for gravure offset printing is filled with a conductive paste for screen printing, the viscosity is too high and transfer to the blanket is difficult, and clogging occurs in the concave portion of the gravure plate.
［グラビアオフセット印刷用導電性ペーストの製造方法］
本発明のグラビアオフセット印刷用導電性ペーストを製造する方法は、特に限定されないが、まず、銀微粒子分散体を調製し、上記銀微粒子分散体と有機溶媒と水溶性高分子と、必要に応じて上記各種成分とを混合することにより、本発明のグラビアオフセット印刷用導電性ペーストを得ることができる。 [Method for producing conductive paste for gravure offset printing]
The method for producing the conductive paste for gravure offset printing according to the present invention is not particularly limited. First, a silver fine particle dispersion is prepared, and the silver fine particle dispersion, the organic solvent, the water-soluble polymer, and, if necessary. The conductive paste for gravure offset printing of the present invention can be obtained by mixing the above various components.
上記銀微粒子分散体の調製方法としては、還元により分解して銀を生成しうる銀化合物と、アミンとの混合液を調製する第１工程と、上記混合液中の上記銀化合物を還元することで表面の少なくとも一部に上記アミンが付着した銀微粒子を生成する第２工程とを含む方法が挙げられる。 As a method for preparing the silver fine particle dispersion, a first step of preparing a mixed solution of a silver compound that can be decomposed by reduction to produce silver and an amine, and reducing the silver compound in the mixed solution And a second step of generating silver fine particles in which the amine is attached to at least a part of the surface.
上記第１工程においては、アミンを銀１ｍｏｌに対して２ｍｏｌ以上添加することが好ましい。上記アミンの添加量を銀１ｍｏｌに対して２ｍｏｌ以上とすることで、還元によって生成される銀微粒子の表面に上記アミンを適量付着させることができ、上記銀微粒子に種々の分散媒に対する優れた分散性と低温焼結性とを付与することができる。 In the first step, it is preferable to add 2 mol or more of amine with respect to 1 mol of silver. By making the addition amount of the amine 2 mol or more with respect to 1 mol of silver, an appropriate amount of the amine can be attached to the surface of the silver fine particles produced by reduction, and the silver fine particles are excellently dispersed in various dispersion media. And low-temperature sinterability can be imparted.
なお、上記第１工程における混合液の組成、及び、上記第２工程における還元条件（例えば、加熱温度及び加熱時間等）は、得られる銀微粒子の粒子径をナノメートルサイズとするように調整することが好ましい。銀微粒子の粒子径をナノメートルサイズとすることで、融点降下が生じ、低温で焼成できるためである。得られる銀微粒子の粒子径は、１～２００ｎｍとすることがより好ましい。必要に応じてミクロンサイズの粒子が含まれていてもよい。上記第２工程で得られる銀微粒子分散体から銀微粒子を取り出す方法は特に限定されないが、例えば、その銀微粒子分散体の洗浄を行う方法等が挙げられる。 In addition, the composition of the liquid mixture in the first step and the reduction conditions (for example, the heating temperature and the heating time) in the second step are adjusted so that the particle diameter of the obtained silver fine particles is a nanometer size. It is preferable. This is because, by setting the particle diameter of the silver fine particles to a nanometer size, a melting point drop occurs and firing can be performed at a low temperature. The particle diameter of the obtained silver fine particles is more preferably 1 to 200 nm. Micron-sized particles may be included as necessary. The method for taking out the silver fine particles from the silver fine particle dispersion obtained in the second step is not particularly limited, and examples thereof include a method for washing the silver fine particle dispersion.
上記表面の少なくとも一部を有機成分で被覆された銀微粒子を得るための出発材料としては、種々の公知の銀化合物を用いることができ、例えば、銀塩又は銀塩の水和物を用いることができる。具体的には、硝酸銀、硫酸銀、塩化銀、酸化銀、酢酸銀、シュウ酸銀、ギ酸銀、亜硝酸銀、塩素酸銀、硫化銀等の銀塩が挙げられる。これらは還元可能なものであれば特に限定されず、適当な溶媒中に溶解させても、溶媒中に分散させたまま使用してもよい。また、これらは単独で用いても複数併用してもよい。なかでも、シュウ酸銀が好ましい。シュウ酸銀は、最も単純なジカルボン酸銀であり、シュウ酸銀を用いて合成されるシュウ酸銀アミン錯体は、低温かつ短時間で還元が進むことから、ナノメートルサイズの銀微粒子の合成に好適である。更に、シュウ酸銀を用いると、合成時には副生成物が発生せず、系外にシュウ酸イオン由来の二酸化炭素が出るのみであるため、合成後に精製の手間が少ない。 As a starting material for obtaining silver fine particles in which at least a part of the surface is coated with an organic component, various known silver compounds can be used, for example, a silver salt or a hydrate of silver salt is used. Can do. Specific examples include silver salts such as silver nitrate, silver sulfate, silver chloride, silver oxide, silver acetate, silver oxalate, silver formate, silver nitrite, silver chlorate, and silver sulfide. These are not particularly limited as long as they can be reduced, and may be dissolved in an appropriate solvent or may be used as dispersed in a solvent. These may be used alone or in combination. Of these, silver oxalate is preferred. Silver oxalate is the simplest silver dicarboxylate, and the silver oxalate amine complex synthesized using silver oxalate is reduced at a low temperature in a short time. Is preferred. Furthermore, when silver oxalate is used, no by-product is generated during the synthesis, and only carbon dioxide derived from oxalate ions is generated outside the system.
上記銀化合物を還元する方法としては、加熱が好ましい。上記加熱の方法は特に限定されない。上記加熱により上記銀化合物を還元する方法としては、例えば、シュウ酸銀等の銀化合物とアミン等の有機成分から生成される錯化合物を加熱して、上記錯化合物に含まれるシュウ酸イオン等の金属化合物を分解して生成する原子状の銀を凝集させる方法が挙げられる。上記方法により、アミン等の有機成分の保護膜に被覆された銀微粒子を製造することができる。 Heating is preferred as a method for reducing the silver compound. The heating method is not particularly limited. As a method of reducing the silver compound by the heating, for example, a complex compound produced from a silver compound such as silver oxalate and an organic component such as amine is heated, and the oxalate ion contained in the complex compound or the like. A method of aggregating atomic silver produced by decomposing a metal compound is mentioned. By the above method, silver fine particles coated with a protective film of an organic component such as amine can be produced.
このように、銀化合物の錯化合物をアミンの存在下で熱分解することで、アミンにより被覆された銀微粒子を製造する金属アミン錯体分解法においては、単一種の分子である銀アミン錯体の分解反応により原子状銀が生成するため、反応系内に均一に原子状銀を生成することが可能であり、複数の成分間の反応により銀原子を生成する場合に比較して、反応を構成する成分の組成揺らぎに起因する反応の不均一が抑制され、特に工業的規模で多量の銀粉末を製造する際に有利である。 Thus, in the metal amine complex decomposition method for producing silver fine particles coated with amine by thermally decomposing a complex compound of silver compound in the presence of amine, decomposition of silver amine complex which is a single kind of molecule is performed. Since atomic silver is generated by the reaction, it is possible to generate atomic silver uniformly in the reaction system, and the reaction is configured as compared to the case of generating silver atoms by reaction between multiple components. Inhomogeneity of the reaction due to fluctuations in the composition of the components is suppressed, which is particularly advantageous when a large amount of silver powder is produced on an industrial scale.
また、金属アミン錯体分解法においては、生成する銀原子にアミン分子が配位結合しており、上記銀原子に配位したアミン分子の働きにより凝集を生じる際の銀原子の運動がコントロールされるものと推察される。この結果として、金属アミン錯体分解法によれば非常に微細で、粒度分布が狭い金属粒子を製造することが可能となる。 In the metal amine complex decomposition method, an amine molecule is coordinated to the silver atom to be generated, and the movement of the silver atom during aggregation is controlled by the action of the amine molecule coordinated to the silver atom. Inferred. As a result, according to the metal amine complex decomposition method, it is possible to produce metal particles that are very fine and have a narrow particle size distribution.
更に、製造される銀微粒子の表面にも多数のアミン分子が比較的弱い力の配位結合を生じており、これらが銀微粒子の表面に緻密な保護膜を形成するため、保存安定性に優れる表面の清浄な有機被覆銀微粒子を製造することが可能となる。また、上記被膜を形成するアミン分子は加熱等により容易に脱離可能であるため、非常に低温で焼結可能な銀微粒子を製造することが可能となる。 Furthermore, a large number of amine molecules form a relatively weak coordination bond on the surface of the silver fine particles to be produced, and these form a dense protective film on the surface of the silver fine particles, so that the storage stability is excellent. It becomes possible to produce organic coated silver fine particles having a clean surface. In addition, since the amine molecules forming the film can be easily desorbed by heating or the like, silver fine particles that can be sintered at a very low temperature can be produced.
また、固体状の銀化合物とアミンを混合して錯化合物等の複合化合物が生成する際に、被覆銀微粒子の被膜を構成する酸価をもつ分散剤に対して、アミンを混合して用いることにより、錯化合物等の複合化合物の生成が容易になり、短時間の混合で複合化合物を製造可能となる。また、上記アミンを混合して用いることにより、各種の用途に応じた特性を有する被覆銀微粒子の製造が可能である。 Also, when a solid silver compound and an amine are mixed to form a complex compound such as a complex compound, the amine is mixed with the dispersant having an acid value constituting the coating of the coated silver fine particles. This facilitates the generation of a complex compound such as a complex compound, and makes it possible to produce the complex compound by mixing in a short time. Further, by mixing and using the amine, it is possible to produce coated silver fine particles having characteristics according to various uses.
上記のようにして得られたアミンや酸価をもつ保護分散剤で被覆された銀微粒子を含む分散液には、銀微粒子の他に、金属塩の対イオン、分散剤、還元剤の残留物等が存在しており、液全体の電解質濃度や有機物濃度が高い傾向にある。このような状態の液は、電導度が高い等の理由で金属粒子の凝析が起こり、沈殿し易い。または、沈殿しなくても、金属塩の対イオン、分散に必要な量以上の過剰な分散剤、又は、還元剤の残留物等が残留していると、導電性を悪化させるおそれがある。そこで、上記銀微粒子を含む溶液を洗浄して余分な残留物を取り除くことにより、有機成分で被覆された銀微粒子を確実に得ることができる。 In the dispersion liquid containing silver fine particles coated with an amine or a protective dispersant having an acid value obtained as described above, in addition to the silver fine particles, a metal salt counter ion, a dispersant, and a reducing agent residue Etc. exist, and the electrolyte concentration and organic substance concentration of the whole liquid tend to be high. The liquid in such a state is likely to precipitate due to the coagulation of the metal particles due to high electrical conductivity. Or, even if it does not precipitate, if the counter ion of the metal salt, the excessive dispersant more than the amount necessary for dispersion, or the residue of the reducing agent remains, the conductivity may be deteriorated. Therefore, by washing the solution containing the silver fine particles to remove excess residues, the silver fine particles coated with the organic component can be reliably obtained.
上記洗浄方法としては、例えば、表面の少なくとも一部を有機成分で被覆された銀微粒子を含む分散液を一定時間静置し、上澄み液を取り除いた後、銀微粒子を沈殿させる溶媒（例えば、水、メタノール、メタノール／水混合溶媒等）を加えて撹枠し、再度一定期間静置して上澄み液を取り除く工程を幾度か繰り返す方法が挙げられる。他の方法としては、上記の静置の代わりに遠心分離を行う方法、限外濾過装置やイオン交換装置等により脱塩する方法等が挙げられる。このような洗浄によって余分な残留物を取り除くと共に溶媒を除去することにより、表面の少なくとも一部を有機成分で被覆された銀微粒子を得ることができる。 As the cleaning method, for example, a dispersion containing silver fine particles having at least a part of the surface coated with an organic component is allowed to stand for a certain period of time, and after removing the supernatant liquid, a solvent that precipitates silver fine particles (for example, water , Methanol, methanol / water mixed solvent, etc.), and a method of repeating the process several times by removing the supernatant liquid by standing again for a certain period of time. Examples of other methods include a method of performing centrifugation instead of the above standing, a method of desalting with an ultrafiltration device, an ion exchange device, or the like. By removing excess residues and removing the solvent by such washing, silver fine particles in which at least a part of the surface is coated with an organic component can be obtained.
上記銀微粒子分散体と有機溶媒と水溶性高分子とを混合する方法は特に限定されず、攪拌機やスターラー等を用いて従来公知の方法によって行うことができる。スパチュラのようなもので撹拌したりして、適当な出力の超音波ホモジナイザーを当ててもよい。 The method for mixing the silver fine particle dispersion, the organic solvent, and the water-soluble polymer is not particularly limited, and can be performed by a conventionally known method using a stirrer or a stirrer. An ultrasonic homogenizer with an appropriate output may be applied by stirring with a spatula or the like.
［導電性パターンの形成方法］
本発明のグラビアオフセット印刷用導電性ペーストを用いることで、グラビア版を用いたグラビアオフセット印刷法によって精細な導電性パターンを形成することができる。すなわち、グラビア版を用いたグラビアオフセット印刷法を用い、上記グラビア版は、印刷面にグラビアオフセット印刷用導電性ペーストが充填される凹部を有し、上記凹部の幅は、１０μｍ以下であり、上記グラビアオフセット印刷用導電性ペーストは、本発明のグラビアオフセット印刷用導電性ペーストである導電性パターンの形成方法もまた、本発明の一態様である。 [Method of forming conductive pattern]
By using the conductive paste for gravure offset printing of the present invention, a fine conductive pattern can be formed by a gravure offset printing method using a gravure plate. That is, using the gravure offset printing method using a gravure plate, the gravure plate has a recess filled with a conductive paste for gravure offset printing on the printing surface, the width of the recess is 10 μm or less, The conductive paste for gravure offset printing is also an embodiment of the present invention, and a method for forming a conductive pattern which is the conductive paste for gravure offset printing of the present invention.
以下に図１を用いて、グラビアオフセット印刷法を用いて基材６０に導電性ペーストを塗布する方法について説明する。図１は、グラビアオフセット印刷法の一例を模式的に示した概念図である。図１に示したように、グラビアオフセット印刷用印刷装置１００は、グラビア版４０と、ブランケット５０とを備える。グラビアオフセット印刷用印刷装置１００は、更に、グラビアオフセット印刷用導電性ペースト１０を上記グラビア版４０に塗布するためのピックアップロール２０と、余剰な導電性ペースト１０を取り除くブレード３０を備えることが好ましい。 Hereinafter, a method of applying a conductive paste to the substrate 60 using the gravure offset printing method will be described with reference to FIG. FIG. 1 is a conceptual diagram schematically showing an example of a gravure offset printing method. As shown in FIG. 1, the gravure offset printing apparatus 100 includes a gravure plate 40 and a blanket 50. The gravure offset printing apparatus 100 preferably further includes a pick-up roll 20 for applying the gravure offset printing conductive paste 10 to the gravure plate 40 and a blade 30 for removing excess conductive paste 10.
上記グラビア版４０は、印刷面に上記グラビアオフセット印刷用導電性ペースト１０が充填される凹部４１を有する。上記凹部４１の幅Ｗは、１０μｍ以下である。上記凹部４１の幅Ｗを１０μｍ以下とすることで、線幅が１０μｍ以下の導電性パターンを形成することができる。上記凹部４１の幅Ｗは、５μｍ以下であることが好ましく、３μｍ以下であることがより好ましい。本発明のグラビアオフセット印刷用導電性ペーストを用いることで、上記凹部４１の幅Ｗが３μｍ以下のグラビア版を用いても、断線することなく、線幅が３μｍ以下の微細導電性パターンを形成することができる。上記グラビア版４０は、板状であっても、筒状であってもよい。 The gravure plate 40 has a recess 41 in which the printing surface is filled with the conductive paste 10 for gravure offset printing. The width W of the recess 41 is 10 μm or less. By setting the width W of the recess 41 to 10 μm or less, a conductive pattern having a line width of 10 μm or less can be formed. The width W of the recess 41 is preferably 5 μm or less, and more preferably 3 μm or less. By using the gravure offset printing conductive paste of the present invention, a fine conductive pattern having a line width of 3 μm or less is formed without disconnection even when a gravure plate having a width W of 3 μm or less is used. be able to. The gravure plate 40 may be plate-shaped or cylindrical.
上記ブランケット５０は、シリコーンゴム層を有しているものが好ましい。上記ブランケット５０としては、例えば、金陽社製のシルブランシリーズ、藤倉ゴム工業社製の＃７００－ＳＴＤ等を用いることができる。上記ブランケット５０は、板状であっても、筒状であってもよい。 The blanket 50 preferably has a silicone rubber layer. As the blanket 50, for example, Syl Blanc series manufactured by Kinyo Co., Ltd., # 700-STD manufactured by Fujikura Rubber Industrial Co., Ltd., or the like can be used. The blanket 50 may be plate-shaped or cylindrical.
上記基材６０としては、グラビアオフセット印刷用導電性ペースト１０を塗布して加熱により焼成して導電性パターンを搭載することのできる、少なくとも１つの主面を有するものであれば、特に制限はないが、耐熱性に優れた基材であるのが好ましい。また、本発明のグラビアオフセット印刷用導電性ペーストは、従来の導電性インク及び導電性ペーストと比較して低い温度で加熱して焼成しても充分な導電性を有する導電性パターンを得ることができるため、この低い焼成温度よりも高い温度範囲で、従来よりも耐熱温度の低い基材を用いることが可能である。 The substrate 60 is not particularly limited as long as it has at least one main surface on which the conductive paste 10 for gravure offset printing can be applied and baked by heating to mount the conductive pattern. However, it is preferable that it is a base material excellent in heat resistance. Moreover, the conductive paste for gravure offset printing of the present invention can obtain a conductive pattern having sufficient conductivity even when heated and baked at a lower temperature than conventional conductive inks and conductive pastes. Therefore, it is possible to use a base material having a lower heat-resistant temperature than the conventional one in a temperature range higher than this low firing temperature.
上記基材６０を構成する材料としては、例えば、ポリアミド（ＰＡ）、ポリイミド（ＰＩ）、ポリアミドイミド（ＰＡＩ）、ポリエチレンテレフタレート（ＰＥＴ）、ポリブチレンテレフタレート（ＰＢＴ）、ポリエチレンナフタレート（ＰＥＮ）等のポリエステル、ポリカーボネート（ＰＣ）、ポリエーテルスルホン（ＰＥＳ）、ビニル樹脂、フッ素樹脂、液晶ポリマー、セラミックス、ガラス又は金属等が挙げられる。また、上記基材６０は、例えば板状又はストリップ状等の種々の形状であってよく、リジッドでもフレキシブルでもよい。上記基材６０の厚さは、適宜選択することができる。接着性若しくは密着性の向上又はその他の目的のために、表面層が形成された基材や親水化処理等の表面処理を施した基材を用いてもよい。 Examples of the material constituting the substrate 60 include polyamide (PA), polyimide (PI), polyamideimide (PAI), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene naphthalate (PEN). Examples include polyester, polycarbonate (PC), polyethersulfone (PES), vinyl resin, fluororesin, liquid crystal polymer, ceramics, glass, metal, and the like. The substrate 60 may have various shapes such as a plate shape or a strip shape, and may be rigid or flexible. The thickness of the base material 60 can be appropriately selected. For the purpose of improving adhesion or adhesion, or other purposes, a base material on which a surface layer is formed or a base material that has been subjected to a surface treatment such as a hydrophilic treatment may be used.
上記導電性パターンの形成方法は、上記グラビアオフセット印刷用導電性ペースト１０を基材６０に塗布する塗布工程と、基材６０に塗布したグラビアオフセット印刷用導電性ペースト１０を焼成して導電性パターンを形成する焼成工程とを有することが好ましい。 The conductive pattern forming method includes a coating step of applying the gravure offset printing conductive paste 10 to the substrate 60, and baking the gravure offset printing conductive paste 10 applied to the substrate 60 to conduct the conductive pattern. It is preferable to have a firing step for forming the film.
以下に、図１を用いて上記塗布工程の一例を説明する。図１中、ピックアップロール２０、グラビア版４０及びブランケット５０に示した矢印は、それぞれの回転方向を示す。また、基材６０の下方の矢印は、基材６０の移動方向を示す。まず、ピックアップロール２０により導電性ペースト１０をグラビア版４０に塗布し、ブレード３０により余剰な導電性ペースト１０を取り除くことにより、上記グラビア版４０の印刷面に設けられた凹部４１に導電性ペースト１０が充填される（図１の（ａ））。次に、上記凹部４１に充填された導電性ペースト１０が、ブランケット５０に転写される（図１の（ｂ））。その後、上記ブランケット５０に転写された半固体／半液体状態（ウェット状態又は半乾燥状態）の導電性ペースト１０が基材（被着体）６０に転写される（図１の（ｃ））。以上の工程により、基材６０上に、グラビア版４０の表面に形成された印刷パターンに対して反転したパターンが印刷される。 Below, an example of the said application | coating process is demonstrated using FIG. In FIG. 1, the arrows shown on the pickup roll 20, the gravure plate 40, and the blanket 50 indicate the respective rotation directions. Moreover, the arrow below the base material 60 indicates the moving direction of the base material 60. First, the conductive paste 10 is applied to the gravure plate 40 by the pickup roll 20, and the excess conductive paste 10 is removed by the blade 30, whereby the conductive paste 10 is formed in the recess 41 provided on the printing surface of the gravure plate 40. Is filled ((a) of FIG. 1). Next, the conductive paste 10 filled in the concave portion 41 is transferred to the blanket 50 ((b) in FIG. 1). Thereafter, the semi-solid / semi-liquid (wet or semi-dried) conductive paste 10 transferred to the blanket 50 is transferred to the substrate (adhered body) 60 ((c) of FIG. 1). Through the above steps, a pattern that is reversed with respect to the print pattern formed on the surface of the gravure plate 40 is printed on the substrate 60.
導電性ペースト１０を用いて細線を印刷する場合、上記グラビア版４０からブランケット５０への転写時、及び、上記ブランケット５０から基材６０への転写時に、転写不良が起こりやすいが、本発明のグラビアオフセット印刷用導電性ペーストは、水溶性高分子を含有するため、ブランケット５０上に転写された導電性ペースト１０が広がり難く、また、基材６０への充分な密着性及び転写性を有するため、例えば、線幅が１０μｍ以下、特に線幅が３μｍ以下の導電性パターンであっても断線することなく形成することができる。 When a thin line is printed using the conductive paste 10, a transfer defect is likely to occur during transfer from the gravure plate 40 to the blanket 50 and from the blanket 50 to the substrate 60. Since the conductive paste for offset printing contains a water-soluble polymer, the conductive paste 10 transferred onto the blanket 50 is difficult to spread, and has sufficient adhesion and transferability to the substrate 60. For example, even a conductive pattern having a line width of 10 μm or less, particularly a line width of 3 μm or less, can be formed without disconnection.
ブランケット５０の表面に導電性ペースト１０を転写した後、短時間の放置により、低沸点溶剤が揮発及びブランケット５０中に吸収されることにより導電性ペースト１０の粘度が上昇することがある。これに対し、グラビアオフセット印刷用導電性ペースト１０を構成する有機溶媒が、ヒドロキシル基を含有し、常圧での沸点が２００℃以上である第１の有機溶媒、及び／又は、ブランケット膨潤率が２．０％以下の第２の有機溶媒を含有する場合は、ブランケット５０への有機溶媒の吸収が低減されるため、ブランケット５０表面での導電性ペースト１０の乾燥を大幅に抑制することができる。そのため、例えば、線幅が３μｍ以下の細線導電性パターンをより好適に形成することができる。 After transferring the conductive paste 10 to the surface of the blanket 50, the viscosity of the conductive paste 10 may increase due to volatilization of the low boiling point solvent and absorption into the blanket 50 when left for a short time. On the other hand, the organic solvent constituting the conductive paste 10 for gravure offset printing contains a hydroxyl group, the first organic solvent having a boiling point of 200 ° C. or higher at normal pressure, and / or the blanket swelling rate. When 2.0% or less of the second organic solvent is contained, absorption of the organic solvent into the blanket 50 is reduced, so that drying of the conductive paste 10 on the surface of the blanket 50 can be significantly suppressed. . Therefore, for example, a fine wire conductive pattern having a line width of 3 μm or less can be more suitably formed.
上記焼成工程における導電性ペーストの焼成温度は、１４０℃未満であることが好ましく、１２０℃以下であることがより好ましい。本発明のグラビアオフセット印刷用導電性ペーストを用いることで、１４０℃未満の温度で焼成しても、優れた導電性を有する導電性パターンを形成することができる。 The firing temperature of the conductive paste in the firing step is preferably less than 140 ° C, and more preferably 120 ° C or less. By using the conductive paste for gravure offset printing of the present invention, a conductive pattern having excellent conductivity can be formed even when baked at a temperature of less than 140 ° C.
上記焼成を行う方法は特に限定されるものではなく、例えば従来公知のギヤオーブン等を用いることができる。本発明の導電性パターンの形成方法は、本発明のグラビアオフセット印刷用導電性ペーストを用いるため、１４０℃未満（好ましくは１２０℃以下）の低温で加熱しても、高い導電性を発現する導電性パターンを形成することができる。上記焼成の温度の下限は必ずしも限定されず、基材上に導電性パターンを形成できる温度であって、かつ、本発明の効果を損なわない範囲で上記有機成分等を蒸発又は分解により除去できる温度であることが好ましい。本発明の効果を損なわない範囲で一部が残存していてもよいが、望ましくは全て除去されるのが好ましい。本発明の導電性パターンの形成方法は、１２０℃程度の低温で加熱処理できるため、比較的熱に弱い基材上にも導電性パターンを形成することができる。また、焼成時間は特に限定されるものではなく、焼成温度に応じて適宜調整することができる。 The method for performing the firing is not particularly limited, and for example, a conventionally known gear oven or the like can be used. Since the method for forming a conductive pattern of the present invention uses the conductive paste for gravure offset printing of the present invention, even when heated at a low temperature of less than 140 ° C. (preferably 120 ° C. or less), a conductive material that exhibits high conductivity. Sex patterns can be formed. The lower limit of the firing temperature is not necessarily limited, and is a temperature at which a conductive pattern can be formed on a substrate, and the temperature at which the organic components and the like can be removed by evaporation or decomposition within a range not impairing the effects of the present invention. It is preferable that A part may remain within the range that does not impair the effects of the present invention, but it is preferable that all be removed. Since the method for forming a conductive pattern of the present invention can be heat-treated at a low temperature of about 120 ° C., the conductive pattern can be formed even on a substrate that is relatively weak against heat. Further, the firing time is not particularly limited, and can be appropriately adjusted according to the firing temperature.
本発明においては、基本的には不要であるが、上記基材と導電性パターンとの密着性を更に高めるため、上記基材の表面処理を行ってもよい。上記表面処理方法としては、例えば、コロナ処理、プラズマ処理、ＵＶ処理、電子線処理等のドライ処理を行う方法、基材上にあらかじめプライマー層や導電性ペースト受容層を設ける方法等が挙げられる。 In the present invention, although basically unnecessary, surface treatment of the substrate may be performed in order to further improve the adhesion between the substrate and the conductive pattern. 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.
上記焼成工程後の導電性パターンの膜厚は、例えば、０．１～５μｍであり、好ましくは０．１～１μｍである。本発明の導電性パターンの形成方法は、本発明のグラビアオフセット印刷用導電性ペーストを用いるため、膜厚が０．１～５μｍ程度であっても、充分な導電性を有する導電性パターンが得られる。 The film thickness of the conductive pattern after the firing step is, for example, 0.1 to 5 μm, preferably 0.1 to 1 μm. Since the method for forming a conductive pattern of the present invention uses the conductive paste for gravure offset printing of the present invention, a conductive pattern having sufficient conductivity can be obtained even when the film thickness is about 0.1 to 5 μm. It is done.
なお、導電性パターンの膜厚ｔは、レーザー顕微鏡（例えば、キーエンス社製のレーザー顕微鏡ＶＫ－９５１０）で測定可能である。また、導電性パターンの膜厚ｔは、下記式を用いて求めることができる。
　式：ｔ＝ｍ／（ｄ×Ｍ×ｗ）
ｍ：導電性パターン重量（スライドガラス上に形成した導電性パターンの重さを電子天秤で測定）
ｄ：導電性パターン密度（ｇ／ｃｍ３）（銀の場合は１０．５ｇ／ｃｍ３）
Ｍ：導電性パターン長（ｃｍ）（スライドガラス上に形成した導電性パターンの長さをＪＩＳ１級相当のスケールで測定）
ｗ：導電性パターン幅（ｃｍ）（スライドガラス上に形成した導電性パターンの幅をＪＩＳ１級相当のスケールで測定） The film thickness t of the conductive pattern can be measured with a laser microscope (for example, a laser microscope VK-9510 manufactured by Keyence Corporation). The film thickness t of the conductive pattern can be obtained using the following formula.
Formula: t = m / (d × M × w)
m: Weight of the conductive pattern (Measure the weight of the conductive pattern formed on the slide glass with an electronic balance)
d: Conductive pattern density (g / cm 3 ) (10.5 g / cm 3 in the case of silver)
M: Conductive pattern length (cm) (Measured length of conductive pattern formed on slide glass on a scale equivalent to JIS class 1)
w: Conductive pattern width (cm) (Measured width of the conductive pattern formed on the slide glass on a scale equivalent to JIS class 1)
本発明の導電性パターンの形成方法により得られる導電性パターンの体積抵抗値は、１１０μΩ・ｃｍ以下であることが好ましく、１００μΩ・ｃｍ以下であることがより好ましく、５０μΩ・ｃｍ以下であることが更に好ましい。上記体積抵抗値は、例えば、以下の方法により測定することができる。まず、ＰＥＴ基材上に幅１ｍｍ、長さ１．５ｃｍの導電性ペーストのパターンを形成し、ギヤオーブン中で１２０℃、３０分間焼成することにより焼結させ、被膜（導電性パターン）を形成する。その後、被膜の抵抗値Ｒ、及び、被膜の厚さｔを測定する。被膜の抵抗値Ｒは、例えば、三和電気計器社製の「デジタルマルチメーターＰＭ－３」を用いて測定することができる。被膜の厚さｔは、例えば、キーエンス社製の形状測定レーザマイクロスコープ「ＶＫ－Ｘ１００」を用いて測定することができる。得られた値から、下記式（１）に基づき体積抵抗値を換算することができる。
　式（１）：（体積抵抗値ρｖ）＝（抵抗値Ｒ）×（被膜幅ｗ）×（被膜厚さｔ）／（端子間距離Ｌ） The volume resistance value of the conductive pattern obtained by the conductive pattern forming method of the present invention is preferably 110 μΩ · cm or less, more preferably 100 μΩ · cm or less, and 50 μΩ · cm or less. Further preferred. The volume resistance value can be measured, for example, by the following method. First, a conductive paste pattern with a width of 1 mm and a length of 1.5 cm is formed on a PET substrate, and sintered by baking at 120 ° C. for 30 minutes in a gear oven to form a coating (conductive pattern) To do. Thereafter, the resistance value R of the coating and the thickness t of the coating are measured. The resistance value R of the film can be measured using, for example, “Digital Multimeter PM-3” manufactured by Sanwa Electric Instruments Co., Ltd. The thickness t of the coating can be measured, for example, using a shape measurement laser microscope “VK-X100” manufactured by Keyence Corporation. From the obtained value, the volume resistance value can be converted based on the following formula (1).
Formula (1): (Volume resistance value ρv) = (resistance value R) × (film width w) × (film thickness t) / (distance L between terminals)
本発明の導電性パターンの形成方法を用いて、基材上に導電性パターンを描画する導電性基板の製造方法もまた、本発明の一態様である。上記基材としては、本発明の導電性パターンの形成方法で説明した基材と同様のものを用いることができる。本発明の導電性基板の製造方法は、本発明のグラビアオフセット印刷用導電性ペーストを用いた導電性パターンの形成方法を用いるため、例えば、線幅が１０μｍ以下、特に線幅が３μｍ以下の細線導電性パターンの形成することができる。そのため、精密な電子回路を備えた導電性基板を製造することができる。上記導電性基板としては、例えば、電子回路基板等が挙げられる。上記導電性パターンは、例えば、電子回路基板上に形成される配線等である。 The manufacturing method of the conductive substrate which draws a conductive pattern on a base material using the formation method of the conductive pattern of the present invention is also one mode of the present invention. As said base material, the thing similar to the base material demonstrated with the formation method of the electroconductive pattern of this invention can be used. Since the method for producing a conductive substrate of the present invention uses the method for forming a conductive pattern using the conductive paste for gravure offset printing of the present invention, for example, a thin wire having a line width of 10 μm or less, particularly a line width of 3 μm or less. A conductive pattern can be formed. Therefore, a conductive substrate provided with a precise electronic circuit can be manufactured. Examples of the conductive substrate include an electronic circuit substrate. The conductive pattern is, for example, a wiring formed on an electronic circuit board.
以下、本発明について実施例を掲げて更に詳しく説明するが、本発明はこれらの実施例のみに限定されるものではない。 EXAMPLES Hereinafter, although an Example is hung up and demonstrated in more detail about this invention, this invention is not limited only to these Examples.
＜合成例１＞
（銀微粒子分散体の調製）
３－メトキシプロピルアミン（炭素数：４）９．０ｇと、高分子分散剤であるＤＩＳＰＥＲＢＹＫ－１０２　０．２ｇとを混合し、マグネティックスターラーにてよく撹拌してアミン混合液を生成した。次いで、撹拌を行いながら、シュウ酸銀３．０ｇを添加した。シュウ酸銀の添加後、室温で攪拌を続けることでシュウ酸銀を粘性のある白色の物質へと変化させ、上記変化が外見的に終了したと認められる時点で撹拌を終了した（第１工程）。 <Synthesis Example 1>
(Preparation of silver fine particle dispersion)
9.0 g of 3-methoxypropylamine (carbon number: 4) and 0.2 g of DISPERBYK-102 which is a polymer dispersant were mixed and stirred well with a magnetic stirrer to produce an amine mixture. Next, 3.0 g of silver oxalate was added while stirring. After the addition of silver oxalate, stirring was continued at room temperature to change the silver oxalate to a viscous white substance, and stirring was terminated when the above change was apparently finished (first step) ).
得られた混合液をオイルバスに移し、１２０℃で加熱撹拌を行った。撹拌の開始直後に二酸化炭素の発生を伴う反応が開始し、その後、二酸化炭素の発生が完了するまで撹拌を行うことで、銀微粒子がアミン混合物中に懸濁した懸濁液を得た（第２工程）。 The obtained mixed solution was transferred to an oil bath and heated and stirred at 120 ° C. The reaction with the generation of carbon dioxide started immediately after the start of stirring, and then stirring was performed until the generation of carbon dioxide was completed, thereby obtaining a suspension in which silver fine particles were suspended in the amine mixture (No. 1). 2 steps).
上記懸濁液の分散媒を置換するため、メタノールと水の混合溶媒１０ｍＬを加えて撹拌後、遠心分離により銀微粒子を沈殿させて分離した。次に、分離した銀微粒子に対してメタノールと水の混合溶媒１０ｍＬを加え、撹拌及び遠心分離を行うことで銀微粒子を沈殿させて精製分離した。分離した銀微粒子を室温で２０分乾燥させ、スラリー状の合成例１の銀微粒子分散体を得た。 In order to replace the dispersion medium of the suspension, 10 mL of a mixed solvent of methanol and water was added and stirred, and then silver fine particles were precipitated and separated by centrifugation. Next, 10 mL of a mixed solvent of methanol and water was added to the separated silver fine particles, and stirring and centrifugation were performed to precipitate and separate the silver fine particles. The separated silver fine particles were dried at room temperature for 20 minutes to obtain a slurry-like silver fine particle dispersion of Synthesis Example 1.
合成例１で得られた銀微粒子分散体に含まれる銀微粒子の平均粒子径は、３２ｎｍであった。上記平均粒子径は、得られた銀微粒子分散体を分散溶媒で１００倍希釈し、堀場製作所社製の粒子径分布測定装置（型番：ＬＢ－５５０）を用いて、動的光散乱法により算出した。分散溶媒としてはターピネオールを用い、溶媒屈折率を１．４８３として測定した。 The average particle diameter of the silver fine particles contained in the silver fine particle dispersion obtained in Synthesis Example 1 was 32 nm. The average particle size is calculated by the dynamic light scattering method using a particle size distribution measuring device (model number: LB-550) manufactured by Horiba, Ltd. by diluting the obtained silver fine particle dispersion 100 times with a dispersion solvent. did. Turpineol was used as a dispersion solvent, and the solvent refractive index was measured as 1.383.
＜実施例１＞
キョーワジオールＰＤ－９を３．０重量部とターピネオールを１４．０重量部混合した有機溶媒に、水溶性高分子としてポリビニルピロリドンＫ３０を３．０重量部溶解した水溶性高分子混合溶液を調製した。上記水溶性高分子が溶けにくい場合は、必要に応じて加温してもよい。 <Example 1>
A water-soluble polymer mixed solution was prepared by dissolving 3.0 parts by weight of polyvinylpyrrolidone K30 as a water-soluble polymer in an organic solvent in which 3.0 parts by weight of Kyowadiol PD-9 and 14.0 parts by weight of terpineol were mixed. . If the above water-soluble polymer is difficult to dissolve, it may be heated as necessary.
合成例１の銀微粒子分散体（ナノ銀）８０．０重量部に対して、上記水溶性高分子混合溶液２０重量部を加え、撹拌棒で混合し、自転・公転ミキサーを用いて撹拌し、続いてデフォーミングを行い、実施例１に係る導電性ペーストを得た。 To 80.0 parts by weight of the silver fine particle dispersion (nanosilver) of Synthesis Example 1, 20 parts by weight of the water-soluble polymer mixed solution is added, mixed with a stirring rod, and stirred using a rotation / revolution mixer. Subsequently, deformation was performed to obtain a conductive paste according to Example 1.
＜実施例２＞
合成例１の銀微粒子分散体８０重量部に対して、加える水溶性高分子をポリビニルピロリドンＫ３０　３．０重量部から、ポリビニルピロリドンＫ２５　３．０重量部に変えたこと以外は、実施例１と同様にして実施例２に係る導電性ペーストを得た。 <Example 2>
Example 1 except that the water-soluble polymer added is changed from 3.0 parts by weight of polyvinylpyrrolidone K30 to 3.0 parts by weight of polyvinylpyrrolidone K25 with respect to 80 parts by weight of the silver fine particle dispersion of Synthesis Example 1. Similarly, a conductive paste according to Example 2 was obtained.
＜実施例３＞
実施例３では、銀微粒子として、平均粒子径０．３μｍのサブミクロンサイズの銀微粒子（サブミクロン銀）（希少金属材料研究所社製、粒径分布０．２～１．０μｍ）を用いた。水溶性高分子混合溶液としては、有機溶媒としてキョーワジオールＰＤ－９を３．０重量部、及び、ターピネオールを１３．０重量部に、水溶性高分子としてポリビニルピロリドンＫ３０を３．０重量部、増粘剤としてＣｒｙｓｔａｓｅｎｓｅＭＰを０．５重量部、高分子分散剤としてＳＯＬＳＰＥＲＳＥ４１０００を０．５重量部溶解した混合溶液を用いた。上記サブミクロンサイズの銀微粒子８０．０重量部に対して、上記水溶性高分子混合溶液を２０重量部加えたこと以外は、実施例１と同様にして実施例３に係る導電性ペーストを得た。 <Example 3>
In Example 3, submicron-sized silver fine particles (submicron silver) (manufactured by Rare Metal Materials Laboratory, particle size distribution 0.2 to 1.0 μm) were used as silver fine particles. . As the water-soluble polymer mixed solution, 3.0 parts by weight of Kyowadiol PD-9 as an organic solvent and 13.0 parts by weight of terpineol, 3.0 parts by weight of polyvinylpyrrolidone K30 as a water-soluble polymer, A mixed solution in which 0.5 part by weight of CrystasenseMP was dissolved as a thickener and 0.5 part by weight of SOLPERSE41000 was dissolved as a polymer dispersant was used. A conductive paste according to Example 3 was obtained in the same manner as Example 1 except that 20 parts by weight of the water-soluble polymer mixed solution was added to 80.0 parts by weight of the submicron-sized silver fine particles. It was.
＜実施例４＞
銀微粒子として、合成例１の銀微粒子分散体６０．０重量部と実施例３で用いたサブミクロンサイズの銀微粒子（希少金属材料研究所社製、粒径分布０．２～１．０μｍ）２０．０重量部とを混合したものを用いた。上記銀微粒子８０．０重量部に対して、実施例３で調製した水溶性高分子混合溶液を２０．０重量部加えたこと以外は、実施例１と同様にして実施例４に係る導電性ペーストを得た。 <Example 4>
As silver fine particles, 60.0 parts by weight of the silver fine particle dispersion of Synthesis Example 1 and the submicron-sized silver fine particles used in Example 3 (manufactured by Rare Metals Laboratory, Inc., particle size distribution 0.2 to 1.0 μm) What mixed 20.0 weight part was used. The conductivity according to Example 4 was the same as Example 1 except that 20.0 parts by weight of the water-soluble polymer mixed solution prepared in Example 3 was added to 80.0 parts by weight of the silver fine particles. A paste was obtained.
＜実施例５＞
実施例５では、キョーワジオールＰＤ－９を３．０重量部、ターピネオールを１４．０重量部混合した有機溶媒に代えて、２－エチル－１，３－ヘキサンジオール異性体混合物を３．０重量部、ターピネオールを１４．０重量部混合した有機溶媒を用いた。合成例１の銀微粒子分散体８０．０重量部に対して、上記混合有機溶媒を１７．０重量部加えたこと以外は、実施例１と同様にして実施例５に係る導電性ペーストを得た。 <Example 5>
In Example 5, instead of the organic solvent in which 3.0 parts by weight of Kyowadiol PD-9 and 14.0 parts by weight of terpineol were mixed, 3.0 weight parts of 2-ethyl-1,3-hexanediol isomer mixture was used. An organic solvent mixed with 14.0 parts by weight of terpineol was used. A conductive paste according to Example 5 was obtained in the same manner as in Example 1 except that 17.0 parts by weight of the mixed organic solvent was added to 80.0 parts by weight of the silver fine particle dispersion of Synthesis Example 1. It was.
＜実施例６＞
実施例６では、ターピネオールを混合せず、２－エチル－１，３－ヘキサンジオール異性体混合物のみの有機溶媒を用いた。
合成例１の銀微粒子分散体８０．０重量部に対して、上記２－エチル－１，３－ヘキサンジオール異性体混合物を１７．０重量部加えたこと以外は、実施例１と同様にして実施例６に係る導電性ペーストを得た。 <Example 6>
In Example 6, an organic solvent containing only 2-ethyl-1,3-hexanediol isomer mixture was used without mixing terpineol.
Example 1 was repeated except that 17.0 parts by weight of the 2-ethyl-1,3-hexanediol isomer mixture was added to 80.0 parts by weight of the silver fine particle dispersion of Synthesis Example 1. A conductive paste according to Example 6 was obtained.
＜実施例７＞
水溶性高分子の添加量を３．０重量部から７．０重量部に変えたこと、キョーワジオールＰＤ－９を３．０重量部、ターピネオールを１０．０重量部混合した有機溶媒を用いたこと以外は、実施例１と同様にして実施例７に係る導電性ペーストを得た。 <Example 7>
The addition amount of the water-soluble polymer was changed from 3.0 parts by weight to 7.0 parts by weight, and an organic solvent mixed with 3.0 parts by weight of Kyowadiol PD-9 and 10.0 parts by weight of terpineol was used. A conductive paste according to Example 7 was obtained in the same manner as Example 1 except that.
＜実施例８＞
水溶性高分子の添加量を３．０重量部から８．０重量部に変えたこと、キョーワジオールＰＤ－９を３．０重量部、ターピネオールを９．０重量部混合した有機溶媒を用いたこと以外は、実施例１と同様にして実施例８に係る導電性ペーストを得た。 <Example 8>
The addition amount of the water-soluble polymer was changed from 3.0 parts by weight to 8.0 parts by weight, and an organic solvent mixed with 3.0 parts by weight of Kyowadiol PD-9 and 9.0 parts by weight of terpineol was used. A conductive paste according to Example 8 was obtained in the same manner as Example 1 except that.
＜比較例１＞
ポリビニルピロリドンＫ３０に代えて、水溶性ではないポリビニルアセトアセタール樹脂（積水化学工業社製、エスレックＫＳ－１０）を３．０重量部加えたこと以外は、実施例１と同様にして比較例１に係る導電性ペーストを得た。 <Comparative Example 1>
Comparative Example 1 was carried out in the same manner as in Example 1 except that 3.0 parts by weight of non-water-soluble polyvinyl acetoacetal resin (manufactured by Sekisui Chemical Co., Ltd., ESREC KS-10) was added instead of polyvinyl pyrrolidone K30. Such a conductive paste was obtained.
＜比較例２＞
ポリビニルピロリドンＫ３０に代えて、水溶性ではないポリビニルブチラール樹脂（積水化学工業社製、エスレックＢＬ－１）を３．０重量部加えたこと以外は、実施例１と同様にして比較例２に係る導電性ペーストを得た。 <Comparative example 2>
According to Comparative Example 2 in the same manner as in Example 1, except that 3.0 parts by weight of polyvinyl butyral resin (manufactured by Sekisui Chemical Co., Ltd., ESREC BL-1), which is not water-soluble, was added instead of polyvinyl pyrrolidone K30. A conductive paste was obtained.
＜比較例３＞
ポリビニルピロリドンＫ３０に代えて、水溶性ではないポリメタクリル酸メチルを３．０重量部加えたこと以外は、実施例１と同様にして比較例３に係る導電性ペーストを得た。 <Comparative Example 3>
A conductive paste according to Comparative Example 3 was obtained in the same manner as Example 1 except that 3.0 parts by weight of polymethyl methacrylate that was not water-soluble was added instead of polyvinyl pyrrolidone K30.
＜比較例４＞
ポリビニルピロリドンＫ３０に代えて、水溶性ではない塩化ビニル－酢酸ビニルコポリマー（ソルバインＡＬ）を３．０重量部加えたこと以外は、実施例１と同様にして比較例４に係る導電性ペーストを得た。 <Comparative example 4>
A conductive paste according to Comparative Example 4 was obtained in the same manner as in Example 1 except that 3.0 parts by weight of a non-water-soluble vinyl chloride-vinyl acetate copolymer (Sorvain AL) was added instead of polyvinylpyrrolidone K30. It was.
＜比較例５＞
ポリビニルピロリドンＫ３０に代えて、水溶性ではない塩化ビニル－酢酸ビニルコポリマー（ソルバインＭ５）を３．０重量部加えたこと以外は、実施例１と同様にして比較例５に係る導電性ペーストを得た。 <Comparative Example 5>
A conductive paste according to Comparative Example 5 was obtained in the same manner as in Example 1 except that 3.0 parts by weight of a non-water-soluble vinyl chloride-vinyl acetate copolymer (Sorvain M5) was added instead of polyvinyl pyrrolidone K30. It was.
＜比較例６＞
ポリビニルピロリドンＫ３０に代えて、水溶性ではない非晶性ポリエステル樹脂（バイロン２００）を３．０重量部加えたこと以外は、実施例１と同様の操作を行ったが、溶媒にバイロン２００が溶解せず、導電性ペーストは得られなかった。 <Comparative Example 6>
The same operation as in Example 1 was performed except that 3.0 parts by weight of non-water-soluble amorphous polyester resin (Byron 200) was added instead of polyvinylpyrrolidone K30, but Byron 200 was dissolved in the solvent. No conductive paste was obtained.
＜比較例７＞
水溶性高分子を添加せずに、合成例１の銀微粒子分散体８０．０重量部に対して、キョーワジオールＰＤ－９を３．０重量部、ターピネオールを１７．０重量部混合した有機溶媒を加えたこと以外は、実施例１と同様にして比較例７に係る導電性ペーストを得た。 <Comparative Example 7>
Organic solvent prepared by mixing 3.0 parts by weight of Kyowadiol PD-9 and 17.0 parts by weight of terpineol with respect to 80.0 parts by weight of the silver fine particle dispersion of Synthesis Example 1 without adding a water-soluble polymer The electroconductive paste which concerns on the comparative example 7 was obtained like Example 1 except having added.
［有機溶媒のブランケット膨潤率］
上記実施例及び比較例で用いた有機溶媒のブランケット膨潤率を、以下の方法により測定した。上記ブランケット膨潤率の測定には、実施例及び比較例で用いたシリコーンブランケット（金陽社製　シルブランＳＰ１１－１（ゴム層０．６ｍｍ　ＰＥＴ層０．２５ｍｍ））を用いた。 [Blanket swelling rate of organic solvent]
The blanket swelling rate of the organic solvent used in the above Examples and Comparative Examples was measured by the following method. For the measurement of the blanket swelling rate, the silicone blanket (Sil Blanc SP11-1 (rubber layer 0.6 mm, PET layer 0.25 mm) manufactured by Kinyo Co., Ltd.) used in Examples and Comparative Examples was used.
上記ブランケットを縦１ｃｍ、横１ｃｍに切り出し、重量を測定した。その後、切り出したブランケットを各種有機溶剤（２０ｇ）に完全に浸漬させ、１０時間放置した。浸漬は室温条件下（２５℃±５℃）にて行った。１０時間後にブランケットを各有機溶剤中から取り出し、付着した溶剤を拭き取り、１分以内に浸漬後のブランケットの重量を測量し、浸漬前後における重量増加率を求めた。得られた数値をブランケット膨潤率とした。下記表１に、各有機溶媒の沸点及び測定したブランケット膨潤率を示した。 The blanket was cut into 1 cm length and 1 cm width, and the weight was measured. Thereafter, the cut blanket was completely immersed in various organic solvents (20 g) and left for 10 hours. Immersion was performed under room temperature conditions (25 ° C. ± 5 ° C.). After 10 hours, the blanket was taken out from each organic solvent, the adhered solvent was wiped off, the weight of the blanket after immersion was measured within 1 minute, and the weight increase rate before and after immersion was determined. The obtained numerical value was defined as the blanket swelling rate. Table 1 below shows the boiling point of each organic solvent and the measured blanket swelling rate.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
［評価試験］
上記実施例及び比較例で得られた導電性ペーストについて、（１）分散性、（２）希釈性、（３）グラビアオフセット印刷での印刷適性、及び、（４）密着性を評価した。更に、上記導電性ペーストで形成された導電性パターンについて、（５）体積抵抗値を測定した。各評価試験の結果を、下記表２及び表３に示した。なお、下記（３）の印刷適性において、幅３μｍ又は５μｍの導電性パターンを形成できた実施例及び比較例に対して、下記（３）印刷適性における導電性パターンの広がり、（４）密着性及び（５）体積抵抗値の評価を行った。 [Evaluation test]
The conductive pastes obtained in the above Examples and Comparative Examples were evaluated for (1) dispersibility, (2) dilution, (3) printability in gravure offset printing, and (4) adhesion. Furthermore, (5) volume resistance value was measured about the conductive pattern formed with the said conductive paste. The results of each evaluation test are shown in Table 2 and Table 3 below. In addition, in the printability of (3) below, with respect to Examples and Comparative Examples in which a conductive pattern having a width of 3 μm or 5 μm was formed, the following (3) Spread of the conductive pattern in printability, (4) Adhesiveness And (5) volume resistance value was evaluated.
（１）分散性
導電性ペーストを分散溶媒（ターピネオール）で２倍希釈して容器中に静置し、室温で１日放置し、その後、沈殿の有無及び上澄みの状態を目視で観察することにより、導電性ペーストの分散性を評価した。容器下に沈降物がほとんど認められない場合を「○」、沈降物が少量認められた場合を「△」、容器上下で明らかに濃度差があり、沈降物がはっきり認められる場合を「×」と評価した。 (1) By diluting the dispersible conductive paste twice with a dispersion solvent (terpineol), allowing it to stand in a container and leaving it at room temperature for 1 day, and then visually observing the presence or absence of precipitation and the state of the supernatant. The dispersibility of the conductive paste was evaluated. “○” when almost no sediment is observed under the container, “△” when a small amount of sediment is observed, and “×” when there is a clear difference in concentration between the top and bottom of the container and sediment is clearly observed. It was evaluated.
（２）希釈性
導電性ペーストを分散媒（ターピネオール）で１００倍希釈し、希釈直後（初期）の分散性と、室温で１週間放置した後の分散性を、それぞれ目視で評価した。凝集や銀鏡が見られない場合を「○」、一部凝集や銀鏡が見られた場合を「△」、凝集・沈殿が生じた場合を「×」と評価した。 (2) Dilutable conductive paste was diluted 100 times with a dispersion medium (terpineol), and the dispersibility immediately after the dilution (initial) and the dispersibility after standing at room temperature for 1 week were evaluated visually. The case where aggregation or silver mirror was not observed was evaluated as “◯”, the case where partial aggregation or silver mirror was observed as “Δ”, and the case where aggregation / precipitation occurred was evaluated as “x”.
（３）印刷適性
手刷りによる簡易グラビアオフセット印刷法を用いて、以下の方法により印刷適性の評価を行った。グラビア版としては、幅３μｍ、深さ５μｍの凹部が複数設けられた第１のグラビア版、及び、幅５μｍ、深さ５μｍの凹部が複数設けられた第２のグラビア版を準備した。凹部の幅が３μｍのグラビア版（第１のグラビア版）、凹部の幅が５μｍのグラビア版（第２のグラビア版）は共に、シンク・ラボラトリー株式会社製の「平板バラードめっき凹版」を用いた。 (3) Printability Using a simple gravure offset printing method by hand printing, printability was evaluated by the following method. As the gravure plate, a first gravure plate having a plurality of recesses having a width of 3 μm and a depth of 5 μm and a second gravure plate having a plurality of recesses having a width of 5 μm and a depth of 5 μm were prepared. Both the gravure plate having a recess width of 3 μm (first gravure plate) and the gravure plate having a recess width of 5 μm (second gravure plate) used “plate ballad plating intaglio plate” manufactured by Sink Laboratories. .
上記第１及び第２のグラビア版の凹部に、ドクターブレードにより実施例及び比較例の導電性ペーストを充填した後、シリコーンブランケットを巻きつけたゴムローラーに押圧、接触させ、所望のパターンをブランケット上に転写させた。その後、該ブランケット上の塗膜を、枚葉のＰＥＴフィルム（厚さ１００μｍ）に押圧、転写して印刷し、線幅約３μｍと５μｍの印刷パターン（印刷配線）を作製した。上記シリコーンブランケットとしては、金陽社製シルブランＳＰ１１－１（ゴム層０．６ｍｍ　ＰＥＴ層０．２５ｍｍ）を用いた。 The concave portions of the first and second gravure plates are filled with the conductive pastes of the examples and comparative examples by a doctor blade, and then pressed and brought into contact with a rubber roller around which a silicone blanket is wound so that a desired pattern is formed on the blanket. Was transcribed. Thereafter, the coating film on the blanket was pressed and transferred to a sheet of PET film (thickness: 100 μm) and printed to produce printed patterns (printed wiring) having line widths of about 3 μm and 5 μm. As the silicone blanket, Silblanc SP11-1 (rubber layer 0.6 mm, PET layer 0.25 mm) manufactured by Kinyo Co., Ltd. was used.
線（導電性パターン）の直線性に特に優れ、断線箇所なしのものを「◎」、線の直線性に優れ、断線箇所なしのものを「○」、線の直線性に劣り、断線箇所なしのものを「△」、線の直線性に劣り、断線箇所があるものを「×」として評価した。また、線（導電性パターン）の拡がりが無いものを「○」、線の拡がりが僅かにあるものを「△」、線の拡がりが有り明らかな線太りがあるものを「×」とした。 Especially excellent in the linearity of the wire (conductive pattern), “◎” when there is no disconnection, “○” when there is no wire disconnection, “○” when there is no disconnection, poor linearity of the wire, no disconnection The case was evaluated as “Δ”, the case where the linearity of the line was inferior and there was a broken portion was evaluated as “x”. Further, “◯” indicates that the line (conductive pattern) does not expand, “Δ” indicates that the line is slightly expanded, and “x” indicates that the line is expanded and there is an obvious line weight.
（４）密着性試験
プルオフ法によって密着性を評価した。印刷適性評価に用いたＰＥＴ基板上の印刷配線にセロテープ（登録商標）を貼り付け、引き剥がした際の破断状況で評価した。具体的には、印刷配線の５か所に対してセロテープを強く擦り付け、垂直方向に強く引きはがして評価した。印刷配線の剥離が生じたセロテープの枚数が０～１枚の場合を「○」、２～３枚の場合を「△」、４～５枚の場合を「×」とし、全剥離でなく部分的な剥離であっても剥離したものとし１枚として数えた。 (4) Adhesion test Adhesion was evaluated by the pull-off method. The evaluation was performed based on the state of rupture when Cellotape (registered trademark) was affixed to the printed wiring on the PET substrate used for the printability evaluation and peeled off. Specifically, the tape was strongly rubbed against five places of the printed wiring, and was peeled off in the vertical direction for evaluation. When the number of cellophane tapes that have been peeled off is 0 to 1, “○” is used for 2 to 3 sheets, “△” is used for 4 to 5 sheets, and “×” is used for 4 to 5 sheets. Even if it was a typical peeling, it was assumed that it was peeled and counted as one sheet.
（５）体積抵抗値
グラビアオフセット印刷により、実施例及び比較例で得られた導電性ペーストを用いて、ＰＥＴ基材上に幅１ｍｍ、長さ１．５ｃｍの導電性ペーストのパターンを形成し、ギヤオーブン中で１２０℃、３０分間焼成することにより焼結させ、被膜（導電性パターン）を形成した。三和電気計器社製の「デジタルマルチメーターＰＭ－３」を用いて、上記被膜の両端での抵抗値Ｒを測定した。また、キーエンス社製の形状測定レーザマイクロスコープ「ＶＫ－Ｘ１００」を用いて、上記被膜の厚さｔを測定した。その後、下記式（１）に基づき、測定端子間距離と被膜の厚さｔから体積抵抗値を換算した。体積抵抗値が５０μΩ・ｃｍ以下の場合を「◎」、５０μΩ・ｃｍを超え、１００μΩ・ｃｍ以下の場合を「〇」、１００μΩ・ｃｍを超え、１１０μΩ・ｃｍ以下の場合を「△」、１１０μΩ・ｃｍを超える場合を「×」と評価した。結果を表２及び３に示した。
　　式（１）：（体積抵抗値ρｖ）＝（抵抗値Ｒ）×（被膜幅ｗ）×（被膜厚さｔ）／（端子間距離Ｌ） (5) By using the conductive paste obtained in the examples and comparative examples by volume resistance gravure offset printing, a pattern of the conductive paste having a width of 1 mm and a length of 1.5 cm is formed on the PET substrate. Sintering was performed by firing at 120 ° C. for 30 minutes in a gear oven to form a coating (conductive pattern). Using a “Digital Multimeter PM-3” manufactured by Sanwa Denki Keiki Co., Ltd., the resistance value R at both ends of the coating was measured. Further, the thickness t of the coating was measured using a shape measurement laser microscope “VK-X100” manufactured by Keyence Corporation. Then, based on the following formula (1), the volume resistance value was converted from the distance between the measurement terminals and the thickness t of the coating. When the volume resistance value is 50 μΩ · cm or less, “◎”, when it exceeds 50 μΩ · cm, when it is 100 μΩ · cm or less, “◯”, when it exceeds 100 μΩ · cm, and when it is 110 μΩ · cm or less, “△”, 110 μΩ -The case where it exceeded cm was evaluated as "x". The results are shown in Tables 2 and 3.
Formula (1): (Volume resistance value ρv) = (resistance value R) × (film width w) × (film thickness t) / (distance L between terminals)
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
実施例１～８の導電性ペーストは、いずれも分散性及び希釈性に優れるものであった。また、実施例１～８の導電性ペーストを用いると、グラビアオフセット印刷で幅が３μｍの導電性パターンを形成することができた。また、ナノメートルサイズの銀微粒子のみを用いた実施例１、２、５～８の方が印刷適性は高いものの、実施例３及び４の結果より、ナノメートルサイズの銀微粒子だけでなく、サブミクロンサイズの銀微粒子の単独、又は、ナノメートルサイズとサブミクロンサイズの銀微粒子とを混合しても、線幅の狭い導電性パターンの印刷が可能であることが分かった。水溶性高分子の添加量が８重量部である実施例８は、体積抵抗値がやや上昇するものの、細線印刷は可能であった。更に、実施例６の結果から、有機溶媒として、テルペン系溶媒を用いなくともジオール溶媒のみで細線の形成が可能であることから、有機溶媒が有するヒドロキシル基の数は問題にならないことが分かった。 The conductive pastes of Examples 1 to 8 were all excellent in dispersibility and dilutability. When the conductive pastes of Examples 1 to 8 were used, a conductive pattern with a width of 3 μm could be formed by gravure offset printing. Although Examples 1, 2, and 5-8 using only nanometer-sized silver fine particles have higher printability, the results of Examples 3 and 4 show that not only nanometer-sized silver fine particles but also sub It has been found that a conductive pattern having a narrow line width can be printed by using micron-sized silver fine particles alone or by mixing nanometer-sized and submicron-sized silver fine particles. In Example 8 in which the addition amount of the water-soluble polymer was 8 parts by weight, fine line printing was possible although the volume resistance value was slightly increased. Furthermore, from the results of Example 6, it was found that the number of hydroxyl groups in the organic solvent is not a problem because it is possible to form a fine line only with a diol solvent without using a terpene solvent as the organic solvent. .
一方で、比較例１～６の結果より、ポリビニルピロリドン以外の水溶性を有さない樹脂剤では、線幅が３μｍ以下の細線印刷において、導電性ペーストを転写できないことが分かった。また、比較例７より、樹脂剤を添加しない場合には、印刷時に導電性パターンの拡がりが顕著に出てしまい、所望の線幅でも印刷ができなくなることが分かった。 On the other hand, from the results of Comparative Examples 1 to 6, it was found that the resin paste having no water solubility other than polyvinylpyrrolidone cannot transfer the conductive paste in fine line printing with a line width of 3 μm or less. Further, from Comparative Example 7, it was found that when the resin agent was not added, the conductive pattern expanded significantly during printing, and printing could not be performed with a desired line width.
１０　グラビアオフセット印刷用導電性ペースト
２０　ピックアップロール
３０　ブレード
４０　グラビア版
４１　凹部
５０　ブランケット
６０　基材（被着体）
１００　グラビアオフセット印刷用印刷装置 DESCRIPTION OF SYMBOLS 10 Conductive paste 20 for gravure offset printing Pickup roll 30 Blade 40 Gravure plate 41 Recess 50 Blanket 60 Base material (Substrate)
100 Printing device for gravure offset printing

Claims (8)

  1. 銀微粒子と、有機溶媒と、水溶性高分子とを含有し、
    前記銀微粒子の平均粒子径は１μｍ以下であることを特徴とするグラビアオフセット印刷用導電性ペースト。     Contains silver fine particles, an organic solvent, and a water-soluble polymer,
    The conductive paste for gravure offset printing, wherein the silver fine particles have an average particle size of 1 μm or less.
  2. 前記水溶性高分子は、環状構造を有する重合性化合物を含有することを特徴とする請求項１に記載のグラビアオフセット印刷用導電性ペースト。 The conductive paste for gravure offset printing according to claim 1, wherein the water-soluble polymer contains a polymerizable compound having a cyclic structure.
  3. 前記水溶性高分子は、ポリビニルピロリドンを含有することを特徴とする請求項１又は２に記載のグラビアオフセット印刷用導電性ペースト。 The conductive paste for gravure offset printing according to claim 1, wherein the water-soluble polymer contains polyvinylpyrrolidone.
  4. 前記水溶性高分子の含有量は、前記導電性ペースト全体に対して、３～８重量％であることを特徴とする請求項１～３のいずれかに記載のグラビアオフセット印刷用導電性ペースト。 The conductive paste for gravure offset printing according to any one of claims 1 to 3, wherein the content of the water-soluble polymer is 3 to 8% by weight with respect to the entire conductive paste.
  5. 前記有機溶媒は、ヒドロキシル基を含有し、常圧での沸点が２００℃以上である第１の有機溶媒を含有することを特徴とする請求項１～４のいずれかに記載のグラビアオフセット印刷用導電性ペースト。 5. The gravure offset printing according to claim 1, wherein the organic solvent contains a first organic solvent containing a hydroxyl group and having a boiling point of 200 ° C. or higher at normal pressure. Conductive paste.
  6. 前記有機溶媒は、ブランケット膨潤率が２．０％以下の第２の有機溶媒を、前記導電性ペースト全体に対して、３．０～３０重量％含有することを特徴とする請求項１～５のいずれかに記載のグラビアオフセット印刷用導電性ペースト。 6. The organic solvent contains 3.0 to 30% by weight of a second organic solvent having a blanket swelling ratio of 2.0% or less based on the whole of the conductive paste. The conductive paste for gravure offset printing according to any one of the above.
  7. グラビア版を用いたグラビアオフセット印刷法を用い、
    前記グラビア版は、印刷面にグラビアオフセット印刷用導電性ペーストが充填される凹部を有し、
    前記凹部の幅は、１０μｍ以下であり、
    前記グラビアオフセット印刷用導電性ペーストは、請求項１～６のいずれかに記載のグラビアオフセット印刷用導電性ペーストであることを特徴とする導電性パターンの形成方法。     Using gravure offset printing method using gravure plate,
    The gravure plate has a concave portion filled with a conductive paste for gravure offset printing on the printing surface,
    The width of the recess is 10 μm or less,
    The method for forming a conductive pattern, wherein the conductive paste for gravure offset printing is the conductive paste for gravure offset printing according to any one of claims 1 to 6.
  8. 請求項７に記載の導電性パターンの形成方法を用いて、基材上に導電性パターンを描画することを特徴とする導電性基板の製造方法。 A method for producing a conductive substrate, comprising: drawing a conductive pattern on a substrate using the method for forming a conductive pattern according to claim 7.
PCT/JP2017/044157 2017-02-14 2017-12-08 Conductive paste for gravure offset printing, method for forming conductive pattern, and method for manufacturing conductive substrate WO2018150697A1 (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021246858A1 (en) * 2020-06-03 2021-12-09 Mimos Berhad Method of preparing silver nanoparticles for use as ink
WO2023224555A3 (en) * 2022-05-17 2024-01-04 National University Of Singapore A composition and a composite material

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008050378A (en) * 2005-09-26 2008-03-06 Mitsubishi Materials Corp Printing ink and method for manufacturing coated film using the ink
JP2009534498A (en) * 2006-04-18 2009-09-24 東進セミケム株式会社 Paste composition for printing
JP2010177084A (en) * 2009-01-30 2010-08-12 Mitsuboshi Belting Ltd Metal nanoparticle paste and conductive base material
JP2011076899A (en) * 2009-09-30 2011-04-14 Taiyo Holdings Co Ltd Conductive paste
JP2014125635A (en) * 2012-12-26 2014-07-07 Industrial Technology Research Institute Composition for gravure offset printing and gravure offset printing method
JP2014186902A (en) * 2013-03-25 2014-10-02 Fujifilm Corp Production method of conductive film
JP2015166447A (en) * 2014-02-12 2015-09-24 ナガセケムテックス株式会社 Ink composition and transparent electrode
WO2017159611A1 (en) * 2016-03-15 2017-09-21 石原ケミカル株式会社 Fine copper particle dispersion liquid, electroconductive film formation method, and circuit board

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TWI494953B (en) * 2009-10-07 2015-08-01 Sakamoto Jun A conductive thin film structure, and a method for producing a conductive thin film structure

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008050378A (en) * 2005-09-26 2008-03-06 Mitsubishi Materials Corp Printing ink and method for manufacturing coated film using the ink
JP2009534498A (en) * 2006-04-18 2009-09-24 東進セミケム株式会社 Paste composition for printing
JP2010177084A (en) * 2009-01-30 2010-08-12 Mitsuboshi Belting Ltd Metal nanoparticle paste and conductive base material
JP2011076899A (en) * 2009-09-30 2011-04-14 Taiyo Holdings Co Ltd Conductive paste
JP2014125635A (en) * 2012-12-26 2014-07-07 Industrial Technology Research Institute Composition for gravure offset printing and gravure offset printing method
JP2014186902A (en) * 2013-03-25 2014-10-02 Fujifilm Corp Production method of conductive film
JP2015166447A (en) * 2014-02-12 2015-09-24 ナガセケムテックス株式会社 Ink composition and transparent electrode
WO2017159611A1 (en) * 2016-03-15 2017-09-21 石原ケミカル株式会社 Fine copper particle dispersion liquid, electroconductive film formation method, and circuit board

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021246858A1 (en) * 2020-06-03 2021-12-09 Mimos Berhad Method of preparing silver nanoparticles for use as ink
WO2023224555A3 (en) * 2022-05-17 2024-01-04 National University Of Singapore A composition and a composite material

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