WO2021111675A1 - Flame-retardant conductive paste and method for producing said flame-retardant conductive paste - Google Patents

Flame-retardant conductive paste and method for producing said flame-retardant conductive paste Download PDF

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WO2021111675A1
WO2021111675A1 PCT/JP2020/029975 JP2020029975W WO2021111675A1 WO 2021111675 A1 WO2021111675 A1 WO 2021111675A1 JP 2020029975 W JP2020029975 W JP 2020029975W WO 2021111675 A1 WO2021111675 A1 WO 2021111675A1
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Prior art keywords
flame
conductive paste
retardant
resin
coating film
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PCT/JP2020/029975
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French (fr)
Japanese (ja)
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美知夫 幸松
哲郎 古谷
智明 伊藤
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福田金属箔粉工業株式会社
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Priority to CN202080053202.6A priority Critical patent/CN114207742A/en
Publication of WO2021111675A1 publication Critical patent/WO2021111675A1/en

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    • 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
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/02—Elements
    • C08K3/08—Metals
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K5/00—Use of organic ingredients
    • C08K5/49—Phosphorus-containing compounds
    • C08K5/51—Phosphorus bound to oxygen
    • C08K5/52—Phosphorus bound to oxygen only
    • C08K5/521—Esters of phosphoric acids, e.g. of H3PO4
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L101/00—Compositions of unspecified macromolecular compounds
    • 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

Definitions

  • the present invention relates to a flame-retardant conductive paste. Specifically, since the flame-retardant conductive paste contains a phosphoric acid ester compound as a flame retardant, even if a fire breaks out in the vicinity, the dry coating film does not catch fire, or even if it catches fire, the fire is extinguished immediately afterwards.
  • the present invention relates to a flame-retardant conductive paste that can be suitably used for an electrode of a capacitor because it has excellent flame retardancy, has excellent conductivity, and has high adhesion to a base material and is difficult to peel off.
  • capacitors which are a type of electronic component, such as aluminum capacitors, ceramic capacitors, tantalum capacitors, and film capacitors.
  • the basic structure of a capacitor is a structure that stores electricity between conductors that are insulated with an insulating substance.
  • the two poles may become conductive, causing a short circuit and causing a fire.
  • the exterior resin has been made flame-retardant to prevent the combustion of capacitors in response to a fire caused by a short circuit.
  • flame-retardant materials for internal components, and electrodes are also required. Flame retardant is required.
  • Capacitor electrodes can be formed by applying a conductive paste in which a conductive material is dispersed in a resin to a dielectric and then curing it.
  • the conductive paste used for the electrode contains a flame retardant
  • the flame retardant can be imparted, but the specific resistance increases due to the added flame retardant, so that the conductivity decreases.
  • the proportion of the resin contained in the paste decreases, which lowers the film-forming property and the adhesion between the coating film and the base material. There is a risk of peeling.
  • the conventional conductive paste has heat resistance, it cannot be expected to be flame-retardant to the extent that the dry coating film can be prevented from catching fire due to a short-circuit fire.
  • Patent Document 1 describes a thermosetting conductive paste composition in which a phosphoric acid ester group-containing dispersant is blended with a thermosetting conductive paste composition containing a conductive powder, a thermosetting component, and a curing agent. Has been done.
  • the content of the phosphoric acid ester group-containing dispersant is 0.01 part by mass or more and less than 0.5 part by mass when the total amount of the conductive powder and the thermosetting component is 100 parts by mass. Since it is stated that the heat resistance and moisture resistance may decrease when 5 parts by mass or more are contained, the thermosetting conductive paste composition described in Patent Document 1 is flame-retardant to the extent that ignition can be prevented. I can't hope for it.
  • the dry coating material does not ignite, or even if it ignites, it has excellent flame retardancy that extinguishes the fire immediately afterwards, and it has high conductivity, and the adhesion between the coating film and the base material is high, so it peels off.
  • the above technical problem was achieved by obtaining the remarkable finding that a flame-retardant conductive paste that is difficult to obtain can be obtained.
  • the present invention is a flame-retardant conductive paste containing flake-shaped silver particles, a resin, a flame retardant, and an organic solvent, and the solid content of the flake-shaped silver particles, the resin, and the flame retardant is 40 to 90 weight by weight. %, The content of the flake-shaped silver particles in the solid content is 80 to 95% by weight, the weight ratio of the resin to the flame retardant is 91: 9 to 40:60, and the flame retardant is phosphorus. It is a flame retardant conductive paste that is an acid ester compound.
  • the present invention is the flame-retardant conductive paste in which the phosphoric acid ester compound is a condensed phosphoric acid ester compound.
  • the present invention is the flame-retardant conductive paste in which the ticko value of the flame-retardant conductive paste is 1.5 to 2.5.
  • the present invention is the flame-retardant conductive paste having a specific resistance of 2.5 ⁇ 10 -4 ⁇ ⁇ cm or less.
  • the present invention is a method for producing the flame-retardant conductive paste, which is produced by kneading silver particles, a resin, a flame retardant, and an organic solvent.
  • the present invention is a conductive paste containing a phosphoric acid ester compound, even if a fire occurs due to a short circuit inside the capacitor, the dry coating film should not be ignited, or the dry coating film should be extinguished immediately after ignition. It is a highly flame-retardant conductive paste that can prevent the combustion of capacitors.
  • the weight ratio of the resin: phosphoric acid ester compound is 91: 9 to 40:60, it is possible to form a dry coating film having high flame retardancy and strength.
  • the conductive material is flake-shaped silver particles, and the content of the flake-shaped silver particles in the solid content (hereinafter referred to as "solid content") composed of the flake-shaped silver particles, the resin and the flame retardant is 80 to 95% by weight. Therefore, it is possible to form a dry coating film having high conductivity.
  • the thixo value is 1.5 to 2.5, a coating film having a uniform film thickness can be formed, and the flame-retardant conductive paste contributes to work efficiency.
  • the flame-retardant conductive paste in the present invention can be suitably used for the electrodes of capacitors.
  • the present invention is a flame-retardant conductive paste containing flake-shaped silver particles, a resin, a flame retardant, and an organic solvent.
  • the flake-shaped silver particles in the present invention may be flake-shaped silver particles having an average particle size (d50) of 2 to 10 ⁇ m, a specific surface area of 0.2 to 1.5 m 2 / g, and an aspect ratio of 5 to 100. preferable. This is because it contributes to the improvement of conductivity.
  • the average particle size (d50) of silver particles can be measured with a laser diffraction type particle size distribution measuring device or the like.
  • the specific surface area of each silver particle can be measured by the BET method using a fluidized specific surface area automatic measuring device or the like.
  • the specific gravity of silver is set to 10.5, and the major axis (2r) of the flake shape is measured by observing with a field emission scanning electron microscope or the like. It can be calculated by incorporating the specific surface area (S) into [Equation 1] to obtain the thickness (t).
  • Flake-shaped silver particles can be produced by putting granular silver powder having an average particle size of 0.5 to 10 ⁇ m into a ball mill equipped with a stirring blade and rotating the stirring blade to form flakes.
  • the magnitude of the centrifugal force applied to the contents of the container of the stirring ball mill is not particularly limited, but the stirring blade may be rotated so that a centrifugal force of 5 to 300 G is applied to the contents of the container.
  • a well-known metallic ball may be put into the stirring ball mill.
  • the raw material granular silver powder is not particularly limited, and granular silver powder obtained by a conventionally known method such as an atomizing method, an electrolysis method or a chemical reduction method can be used.
  • the solvent to be added is not limited, and examples thereof include water, methanol, ethanol, propanol, butanol, pentanol, dimethyl ketone, diethyl ketone, diethyl ether, dimethyl ether, diphenyl ether, toluene and xylene. These solvents may be used alone or in combination of two or more.
  • the treatment agent to be added is not particularly limited, but nonionic surfactants such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, polyoxyethylene sorbitan fatty acid ester, and sorbitan fatty acid ester can be used. Can be mentioned. These surfactants may be used alone or in combination of two or more as appropriate.
  • fatty acids such as oleic acid, stearic acid and myristic acid can be used as the treatment agent. These fatty acids may be used alone or in combination of two or more.
  • the resin in the present invention is not particularly limited as long as it can be cured by irradiation with heat, ultraviolet rays, visible light, or the like, and the fluororesin, acrylic resin, polyester resin, melamine resin, silicon resin, epoxy resin, etc. Butyral resin, phenoxy resin, and polyimide resin can be exemplified.
  • the present invention contains a phosphoric acid ester compound as a flame retardant.
  • the phosphoric acid ester compound forms a polyphosphoric acid layer on the polymer surface of the coating film, the phosphoric acid ester compound blocks oxygen and imparts flame retardancy that does not ignite or tentatively extinguishes the fire immediately after ignition. it can.
  • the phosphoric acid ester compound is not particularly limited, but a condensed phosphoric acid ester compound is suitable.
  • condensed phosphoric acid ester compound examples include an aromatic condensed phosphoric acid ester compound and a halogen-containing condensed phosphoric acid ester compound, but an aromatic condensed phosphoric acid ester compound is preferable.
  • aromatic condensed phosphoric acid ester compound examples include CR-733S and CR-741 (both manufactured by Daihachi Chemical Industry Co., Ltd.).
  • halogen-containing condensed phosphoric acid ester compound CR-504L (manufactured by Daihachi Chemical Industry Co., Ltd.) can be exemplified.
  • the ratio of the resin to the phosphoric acid ester compound is preferably 91: 9 to 40:60 in terms of weight ratio.
  • the ratio of the phosphoric acid ester compound is more than 60, the concentration of the resin becomes too low and the adhesion to the substrate is lowered, so that the dry coating film may be peeled off and the strength of the coating film is maintained. It may not be possible.
  • the phosphate ester compound increases the specific resistance and decreases the conductivity.
  • the conductive paste in the present invention contains an organic solvent in order to dissolve the solid resin and adjust the viscosity.
  • the organic solvent contained in the present invention is not particularly limited, and examples thereof include isoamyl acetate, butyl carbitol acetate (BCA), butyl carbitol, butyl cellosolve, propylene glycol monomethyl ether, propylene glycol monoethyl ether, and texanol. Can be done.
  • the solid content contained in the flame-retardant conductive paste of the present invention is preferably 40 to 90% by weight, more preferably 80 to 90% by weight.
  • the content of flaky silver particles in the solid content is preferably 80 to 95% by weight, more preferably 88 to 93% by weight.
  • the content of the flake-shaped silver particles is less than 80% by weight, the conductivity is lowered, and if the content is more than 95% by weight, the amount of resin is too small and the strength of the dry coating film is lowered, which is not preferable. ..
  • the viscosity of the flame-retardant conductive paste in the present invention is preferably 20 to 300 dPa ⁇ s. This is because if it is less than 20 dPa ⁇ s or exceeds 300 dPa ⁇ s, a coating film having a uniform film thickness may not be formed.
  • Viscosity can be measured using a rotary viscometer.
  • the thixo value in the present invention is preferably 1.5 to 2.5. This is because if it is less than 1.5 or more than 2.5, a coating film having a uniform film thickness may not be formed.
  • the chixo value in the present invention can be obtained by measuring each viscosity (dPa ⁇ s) of 1 rpm and 10 rpm at 25 ° C. and incorporating it into [Equation 2].
  • the specific resistance of the dry coating film of the flame-retardant conductive paste in the present invention is preferably 2.5 ⁇ 10 -4 ⁇ ⁇ cm or less. This is because it can be used as an electrode of a capacitor.
  • the specific resistance of the dried coating film is calculated by the following [Equation 3] after measuring the resistance value ( ⁇ ) of the cured coating film with a resistance meter by the 4-terminal method.
  • the flame-retardant conductive paste in the present invention can be prepared by kneading flaky silver particles, a resin, a phosphoric acid ester compound and an organic solvent with a grinder for 30 to 60 minutes to adjust the viscosity.
  • a phosphoric acid ester compound may be added to a commercially available conductive paste to a desired concentration and kneaded for 3 to 5 minutes to prepare the paste.
  • the flame-retardant conductive paste in the present invention is applied onto a prepared tantalum or aluminum element and heated at 100 to 150 ° C. for 15 to 30 minutes, or cured by irradiation with ultraviolet rays or visible light depending on the type of resin.
  • the electrode can be formed by allowing the electrode to be formed.
  • Flake-shaped silver particles (average particle size (d50) 7 ⁇ m, specific surface area 0.3 m 2 / g, aspect ratio 10) are mixed with phenoxy resin and butyl carbitol acetate (BCA), and a 3-roll mill (manufactured by Imex Co., Ltd.) ) was uniformly kneaded to obtain a conductive paste.
  • BCA butyl carbitol acetate
  • the obtained conductive paste is 80% by weight of flake-shaped silver particles, 5% by weight of phenoxy resin, and 15% by weight of butyl carbitol acetate.
  • Each conductive paste of Example and Comparative Example was prepared by smelting.
  • the content of the flame retardant in each conductive paste may be expressed as the amount added (phr) with respect to 100% by weight of the resin.
  • the dry coating film was peeled from the base material, and the peeled surface was turned up and dried again at 150 ° C. for 30 minutes.
  • the time is a value at which the measurement is started when the lighter is released.
  • the resistivity of the dry coating film is as follows: After forming a coating film having a width of 4 mm, a length of 40 mm, and a thickness of 20 ⁇ m on a glass substrate, a resistivity meter Millioam High Tester 3540-02 (manufactured by Hioki Denki Co., Ltd.) is used by the 4-terminal method. The volume resistivity (specific resistance / ⁇ ⁇ cm) was calculated from the resistance value ( ⁇ ) by the above [Equation 3].
  • viscosity The viscosity (dPa ⁇ s) of each conductive paste at 25 ° C. was measured with a Viscotester VT-04 (manufactured by Rion Co., Ltd.).
  • the cellophane tape manufactured by Sekisui Co., Ltd.
  • the dry coating film did not adhere to the peeled cellophane tape, and no peeling was observed.
  • Those that were evaluated as ⁇ , those in which part of the dry coating film adhered to the cellophane tape and peeling was observed were evaluated as ⁇ , and those in which all of the dry coating film adhered to the cellophane tape and completely peeled off were evaluated as ⁇ . ..
  • the conductive paste in the present invention has high flame retardancy, so that it does not ignite even if the lighter's fire is brought close to it, or it is extinguished immediately after ignition and dried.
  • the specific resistance of the coating film is low, and in addition, it is a flame-retardant conductive paste that is difficult to peel off.
  • the present invention is a conductive paste that has excellent conductivity of a dry coating film and has high adhesion to a substrate and is difficult to peel off. Therefore, it can be suitably used for a capacitor electrode, and a fire may occur in the vicinity. Even if it does, it does not ignite, or even if it ignites, it has a high flame retardancy that it extinguishes immediately afterwards. Therefore, when used for a capacitor electrode, it is possible to prevent combustion of the capacitor due to a short-circuit fire. It is a conductive and conductive paste. Therefore, the present invention is an invention with high industrial applicability.

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Abstract

[Problem] To provide a flame-retardant conductive paste which is capable of forming a dried coating film that exhibits excellent flame retardancy such that the dried coating film does not catch fire even if there is an outbreak of fire in the vicinity thereof, or such that even in cases where the dried coating film caught fire, the fire is immediately put out, while having excellent electrical conductivity and high adhesion to a base material, thereby being not susceptible to separation from the base material, and which is suitable for use in an electrode of a capacitor. [Solution] A flame-retardant conductive paste which contains flake-like silver particles, a resin, a flame retardant and an organic solvent, wherein: the solid content that is composed of the flake-like silver particles, the resin and the flame retardant is from 40% by weight to 90% by weight; the content of the flake-like silver particles in the solid content is from 80% by weight to 95% by weight; the weight ratio of the resin to the flame retardant is from 91:9 to 40:60; and the flame retardant is composed of a phosphoric acid ester compound.

Description

難燃性導電性ペースト及び該難燃性導電性ペーストの製造方法Flame-retardant conductive paste and method for producing the flame-retardant conductive paste
　本発明は難燃性導電性ペーストに関する。詳しくは、該難燃性導電性ペーストは、難燃剤としてリン酸エステル化合物を含有するため、近辺で出火があったとしても、乾燥塗膜に引火しないか、仮令、引火したとしても直後に鎮火するという優れた難燃性を備えると共に、導電性に優れ、しかも、基材に対する密着性が高くて剥離し難いため、コンデンサの電極に好適に使用できる難燃性導電性ペーストに関する。 The present invention relates to a flame-retardant conductive paste. Specifically, since the flame-retardant conductive paste contains a phosphoric acid ester compound as a flame retardant, even if a fire breaks out in the vicinity, the dry coating film does not catch fire, or even if it catches fire, the fire is extinguished immediately afterwards. The present invention relates to a flame-retardant conductive paste that can be suitably used for an electrode of a capacitor because it has excellent flame retardancy, has excellent conductivity, and has high adhesion to a base material and is difficult to peel off.
　電子部品の一種であるコンデンサには、アルミコンデンサ、セラミックコンデンサ、タンタルコンデンサ、フィルムコンデンサ等の種類がある。 There are various types of capacitors, which are a type of electronic component, such as aluminum capacitors, ceramic capacitors, tantalum capacitors, and film capacitors.
　コンデンサの基本構造は、絶縁性物質で絶縁されている導体間で電気を蓄える構造である。 The basic structure of a capacitor is a structure that stores electricity between conductors that are insulated with an insulating substance.
　しかし、導体を絶縁している絶縁性物質によって十分に絶縁できない状態になると、両極間が導通されて短絡が生じ、出火することがある。 However, if the insulating substance that insulates the conductor makes it impossible to sufficiently insulate, the two poles may become conductive, causing a short circuit and causing a fire.
　短絡による出火に対し、従来は、外装樹脂を難燃化することで、コンデンサの燃焼を防止してきたが、内部構成部材の材料についても難燃化の要求は高まっており、電極に対しても難燃化が要求されている。 Conventionally, the exterior resin has been made flame-retardant to prevent the combustion of capacitors in response to a fire caused by a short circuit. However, there is an increasing demand for flame-retardant materials for internal components, and electrodes are also required. Flame retardant is required.
　コンデンサの電極は導電材料を樹脂に分散させた導電性ペーストを誘電体に塗布した後、硬化させて形成することができる。 Capacitor electrodes can be formed by applying a conductive paste in which a conductive material is dispersed in a resin to a dielectric and then curing it.
　電極に使用する導電性ペーストに難燃剤を含有させると、難燃性は付与できるが、添加した難燃剤によって比抵抗が高まるため導電性が低下する。 If the conductive paste used for the electrode contains a flame retardant, the flame retardant can be imparted, but the specific resistance increases due to the added flame retardant, so that the conductivity decreases.
　特に、短絡出火によっても乾燥塗膜に引火しないよう難燃剤の添加量を増やせば、導電性が非常に低下し、コンデンサの電極としては使用できない虞がある。 In particular, if the amount of flame retardant added is increased so that the dry coating film is not ignited even by a short-circuit fire, the conductivity is greatly reduced and there is a risk that it cannot be used as a capacitor electrode.
　また、難燃剤の含有量が高くなると、ペーストが含有する樹脂の割合が減少することから、製膜性や、塗膜と基材との密着性を低下させるので、乾燥塗膜が誘電体から剥離する虞が生じる。 Further, as the content of the flame retardant increases, the proportion of the resin contained in the paste decreases, which lowers the film-forming property and the adhesion between the coating film and the base material. There is a risk of peeling.
　したがって、従来の導電性ペーストは、耐熱性はあったとしても、短絡出火による乾燥塗膜への引火が防止できる程度の難燃性は望めなかった。 Therefore, even if the conventional conductive paste has heat resistance, it cannot be expected to be flame-retardant to the extent that the dry coating film can be prevented from catching fire due to a short-circuit fire.
　そこで、短絡出火があっても乾燥塗膜への引火を防止できるか、仮令、引火しても直後に鎮火する優れた難燃性を有し、コンデンサの燃焼を抑制できると共に、高い導電性を備え、塗膜と基材との密着性が高くて剥離し難く、コンデンサの電極に好適に使用できる難燃性導電性ペーストの開発が望まれている。 Therefore, it is possible to prevent the dry coating film from catching fire even if there is a short-circuit fire, or it has excellent flame retardancy that extinguishes the fire immediately after it catches fire. Therefore, it is desired to develop a flame-retardant conductive paste that has high adhesion between the coating film and the base material and is difficult to peel off, and can be suitably used for the electrode of a capacitor.
特開２０１６－１３１０７０JP 2016-131070
　特許文献１には、導電性粉末と熱硬化性成分と硬化剤とを含有する熱硬化型導電性ペースト組成物にリン酸エステル基含有分散剤を配合した熱硬化型導電性ペースト組成物が記載されている。 Patent Document 1 describes a thermosetting conductive paste composition in which a phosphoric acid ester group-containing dispersant is blended with a thermosetting conductive paste composition containing a conductive powder, a thermosetting component, and a curing agent. Has been done.
　しかしながら、リン酸エステル基含有分散剤の含有量は導電性粉末及び熱硬化性成分の合計量を１００質量部としたときに、０．０１質量部以上０．５質量部未満であり、０．５質量部以上含有させると、耐熱性および耐湿性が低下する場合があると記載されていることから、特許文献１記載の熱硬化型導電性ペースト組成物に引火が防止できる程度の難燃性は望めない。 However, the content of the phosphoric acid ester group-containing dispersant is 0.01 part by mass or more and less than 0.5 part by mass when the total amount of the conductive powder and the thermosetting component is 100 parts by mass. Since it is stated that the heat resistance and moisture resistance may decrease when 5 parts by mass or more are contained, the thermosetting conductive paste composition described in Patent Document 1 is flame-retardant to the extent that ignition can be prevented. I can't hope for it.
　本発明者らは、前記諸問題点を解決することを技術的課題とし、試行錯誤的な数多くの試作・実験を重ねた結果、フレーク状銀粒子と樹脂と難燃剤と有機溶剤を含有する難燃性導電性ペーストであって、前記フレーク状銀粒子と前記樹脂と前記難燃剤からなる固形分が４０～９０重量％であり、前記固形分における前記フレーク状銀粒子の含有量が８０～９５重量％であり、前記樹脂対前記難燃剤の重量比が９１：９～４０：６０であり、前記難燃剤がリン酸エステル化合物である難燃性導電性ペーストであれば、近辺で出火があったとしても乾燥塗膜に引火しないか、仮令、引火したとしても直後に鎮火する優れた難燃性を備えると共に、導電性が高く、また、塗膜と基材との密着性が高くて剥離し難い難燃性導電性ペーストが得られるという刮目すべき知見を得て、前記技術的課題を達成したものである。 The present inventors have made it a technical problem to solve the above-mentioned problems, and as a result of repeating many trials and trials and experiments, it is difficult to contain flaky silver particles, a resin, a flame retardant, and an organic solvent. A flammable conductive paste in which the solid content of the flake-shaped silver particles, the resin and the flame retardant is 40 to 90% by weight, and the content of the flake-shaped silver particles in the solid content is 80 to 95. If the weight ratio of the resin to the flame retardant is 91: 9 to 40:60, and the flame retardant is a flame retardant conductive paste that is a phosphate ester compound, a fire may occur in the vicinity. Even if it does, the dry coating material does not ignite, or even if it ignites, it has excellent flame retardancy that extinguishes the fire immediately afterwards, and it has high conductivity, and the adhesion between the coating film and the base material is high, so it peels off. The above technical problem was achieved by obtaining the remarkable finding that a flame-retardant conductive paste that is difficult to obtain can be obtained.
　前記技術的課題は次のとおり、本発明によって解決できる。 The technical problem can be solved by the present invention as follows.
　本発明は、フレーク状銀粒子と樹脂と難燃剤と有機溶剤を含有する難燃性導電性ペーストであって、前記フレーク状銀粒子と前記樹脂と前記難燃剤からなる固形分が４０～９０重量％であり、前記固形分における前記フレーク状銀粒子の含有量が８０～９５重量％であり、前記樹脂対前記難燃剤の重量比が９１：９～４０：６０であり、前記難燃剤がリン酸エステル化合物である難燃性導電性ペーストである。 The present invention is a flame-retardant conductive paste containing flake-shaped silver particles, a resin, a flame retardant, and an organic solvent, and the solid content of the flake-shaped silver particles, the resin, and the flame retardant is 40 to 90 weight by weight. %, The content of the flake-shaped silver particles in the solid content is 80 to 95% by weight, the weight ratio of the resin to the flame retardant is 91: 9 to 40:60, and the flame retardant is phosphorus. It is a flame retardant conductive paste that is an acid ester compound.
　また、本発明は、前記リン酸エステル化合物が縮合リン酸エステル化合物である前記難燃性導電性ペーストである。 Further, the present invention is the flame-retardant conductive paste in which the phosphoric acid ester compound is a condensed phosphoric acid ester compound.
　また、本発明は、前記難燃性導電性ペーストのチクソ値が１．５～２．５である前記難燃性導電性ペーストである。 Further, the present invention is the flame-retardant conductive paste in which the ticko value of the flame-retardant conductive paste is 1.5 to 2.5.
　また、本発明は、前記難燃性導電性ペーストの比抵抗が２．５×１０－４Ω・ｃｍ以下である前記難燃性導電性ペーストである。 Further, the present invention is the flame-retardant conductive paste having a specific resistance of 2.5 × 10 -4 Ω · cm or less.
　また、本発明は、銀粒子と樹脂と難燃剤と有機溶剤とを混錬して製造する前記難燃性導電性ペーストの製造方法である。 Further, the present invention is a method for producing the flame-retardant conductive paste, which is produced by kneading silver particles, a resin, a flame retardant, and an organic solvent.
　本発明は、リン酸エステル化合物を含有する導電性ペーストであるから、コンデンサ内部において短絡による出火が起こったとしても、乾燥塗膜には引火しないか、仮令、引火しても直後に鎮火させることができ、コンデンサの燃焼を防止することができる難燃性の高い導電性ペーストである。 Since the present invention is a conductive paste containing a phosphoric acid ester compound, even if a fire occurs due to a short circuit inside the capacitor, the dry coating film should not be ignited, or the dry coating film should be extinguished immediately after ignition. It is a highly flame-retardant conductive paste that can prevent the combustion of capacitors.
　また、本発明は、樹脂：リン酸エステル化合物の重量比が９１：９～４０：６０であるから、難燃性が高くて強度のある乾燥塗膜を形成できる。 Further, in the present invention, since the weight ratio of the resin: phosphoric acid ester compound is 91: 9 to 40:60, it is possible to form a dry coating film having high flame retardancy and strength.
　また、導電材料がフレーク状銀粒子であり、フレーク状銀粒子と樹脂と難燃剤からなる固形分（以下「固形分」と言う）中のフレーク状銀粒子の含有量は８０～９５重量％であるので、導電性が高い乾燥塗膜を形成できる。 Further, the conductive material is flake-shaped silver particles, and the content of the flake-shaped silver particles in the solid content (hereinafter referred to as "solid content") composed of the flake-shaped silver particles, the resin and the flame retardant is 80 to 95% by weight. Therefore, it is possible to form a dry coating film having high conductivity.
　また、チクソ値が１．５～２．５であれば、均一な膜厚の塗膜を形成でき、また、作業効率に資する難燃性導電性ペーストになる。 Further, when the thixo value is 1.5 to 2.5, a coating film having a uniform film thickness can be formed, and the flame-retardant conductive paste contributes to work efficiency.
　したがって、本発明における難燃性導電性ペーストはコンデンサの電極に好適に使用できる。 Therefore, the flame-retardant conductive paste in the present invention can be suitably used for the electrodes of capacitors.
乾燥塗膜に着火した状態（着火あり）と着火しなかった、又は、着火直後に鎮火した状態（着火なし）を表す図である。It is a figure which shows the state which ignited the dry coating film (with ignition) and the state which did not ignite, or extinguished immediately after ignition (without ignition).
　本発明は、フレーク状銀粒子と樹脂と難燃剤と有機溶剤を含有する難燃性導電性ペーストである。 The present invention is a flame-retardant conductive paste containing flake-shaped silver particles, a resin, a flame retardant, and an organic solvent.
　本発明おけるフレーク状銀粒子は、平均粒径（ｄ５０）２～１０μm、比表面積０．２～１．５ｍ２/ｇ、アスペクト比５～１００のフレーク(薄片)状の銀粒子であることが好ましい。導電性の向上に資するからである。 The flake-shaped silver particles in the present invention may be flake-shaped silver particles having an average particle size (d50) of 2 to 10 μm, a specific surface area of 0.2 to 1.5 m 2 / g, and an aspect ratio of 5 to 100. preferable. This is because it contributes to the improvement of conductivity.
　銀粒子の平均粒径（ｄ５０）は、レーザー回折式粒子径分布測定装置等で測定することができる。 The average particle size (d50) of silver particles can be measured with a laser diffraction type particle size distribution measuring device or the like.
　各銀粒子の比表面積は、流動式比表面積自動測定装置等を使用し、ＢＥＴ法によって測定することができる。 The specific surface area of each silver particle can be measured by the BET method using a fluidized specific surface area automatic measuring device or the like.
　各銀粒子のアスペクト比(長径（２ｒ）／厚み（ｔ）)は、銀の比重を１０．５とし、電界放射型走査電子顕微鏡等で観察してフレーク形状の長径（２ｒ）を測定し、比表面積（Ｓ）を［式１］に算入して厚み（ｔ）を求めることによって算出できる。 For the aspect ratio (major axis (2r) / thickness (t)) of each silver particle, the specific gravity of silver is set to 10.5, and the major axis (2r) of the flake shape is measured by observing with a field emission scanning electron microscope or the like. It can be calculated by incorporating the specific surface area (S) into [Equation 1] to obtain the thickness (t).
［式１］　体積(πｒ２ｔ）×１０．５×比表面積(Ｓ)＝表面積（２πｒ２+２πｒｔ） [Equation 1] Volume (πr 2 t) × 10.5 × Specific surface area (S) = surface area (2πr 2 + 2πrt)
　フレーク状銀粒子は撹拌翼を備えたボールミルに平均粒径が０．５～１０μｍの粒状銀粉を入れ、撹拌翼を回転させてフレーク状にすることで作製することができる。 Flake-shaped silver particles can be produced by putting granular silver powder having an average particle size of 0.5 to 10 μm into a ball mill equipped with a stirring blade and rotating the stirring blade to form flakes.
　撹拌ボールミルの容器の内容物に対して加えられる遠心力の大きさは特に限定されないが、容器の内容物に対して５～３００Ｇの遠心力が加わるように撹拌翼を回転させればよい。 The magnitude of the centrifugal force applied to the contents of the container of the stirring ball mill is not particularly limited, but the stirring blade may be rotated so that a centrifugal force of 5 to 300 G is applied to the contents of the container.
　また、撹拌ボールミルには、周知の金属性のボールを投入しても良い。 Further, a well-known metallic ball may be put into the stirring ball mill.
　原料の粒状銀粉は、特に限定されず、従来周知のアトマイズ法、電解法または化学還元法等の方法で得られた粒状銀粉を使用することができる。 The raw material granular silver powder is not particularly limited, and granular silver powder obtained by a conventionally known method such as an atomizing method, an electrolysis method or a chemical reduction method can be used.
　撹拌ボールミルには粒径等の調整のために撹拌時に各種溶媒や各種処理剤を入れることができる。 Various solvents and various treatment agents can be added to the stirring ball mill during stirring to adjust the particle size and the like.
　投入する溶媒は限定されないが、例えば水、メタノール、エタノール、プロパノール、ブタノール、ペンタノール、ジメチルケトン、ジエチルケトン、ジエチルエーテル、ジメチルエーテル、ジフェニルエーテル、トルエン及びキシレンが挙げられる。これらの溶媒は、単独でまたは２種類以上を適宜組み合わせて使用することもできる。 The solvent to be added is not limited, and examples thereof include water, methanol, ethanol, propanol, butanol, pentanol, dimethyl ketone, diethyl ketone, diethyl ether, dimethyl ether, diphenyl ether, toluene and xylene. These solvents may be used alone or in combination of two or more.
　投入する処理剤は特に限定されないが、ポリオキシエチレンアルキルエーテル、ポリオキシエチレンアルキルフェニルエーテル、ポリオキシエチレン脂肪酸エステル、ポリオキシエチレンソルビタン脂肪酸エステル、及び、ソルビタン脂肪酸エステル等の非イオン性界面活性剤を挙げることができる。
　これらの界面活性剤は、単独でまたは２種類以上を適宜組み合わせて使用することもできる。 The treatment agent to be added is not particularly limited, but nonionic surfactants such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, polyoxyethylene sorbitan fatty acid ester, and sorbitan fatty acid ester can be used. Can be mentioned.
These surfactants may be used alone or in combination of two or more as appropriate.
　また、処理剤として、オレイン酸、ステアリン酸及びミリスチン酸等の脂肪酸を使用することもできる。これらの脂肪酸は単独でまたは２種類以上を適宜組み合わせて使用することもできる。 Further, fatty acids such as oleic acid, stearic acid and myristic acid can be used as the treatment agent. These fatty acids may be used alone or in combination of two or more.
　本発明における樹脂は熱又は紫外線や可視光等の照射で硬化させることができるものであれば特に限定されるものではなく、フッ素樹脂、アクリル樹脂、ポリエステル樹脂、メラミン樹脂、シリコン樹脂、エポキシ樹脂、ブチラール樹脂、フェノキシ樹脂、ポリイミド樹脂を例示することができる。 The resin in the present invention is not particularly limited as long as it can be cured by irradiation with heat, ultraviolet rays, visible light, or the like, and the fluororesin, acrylic resin, polyester resin, melamine resin, silicon resin, epoxy resin, etc. Butyral resin, phenoxy resin, and polyimide resin can be exemplified.
　本発明は、難燃剤としてリン酸エステル化合物を含有する。 The present invention contains a phosphoric acid ester compound as a flame retardant.
　リン酸エステル化合物は、塗膜の高分子表面にリン酸エステル化合物がポリリン酸層を形成するため、酸素が遮断され、引火しないか、仮令、引火しても直後に鎮火する難燃性を付与できる。 Since the phosphoric acid ester compound forms a polyphosphoric acid layer on the polymer surface of the coating film, the phosphoric acid ester compound blocks oxygen and imparts flame retardancy that does not ignite or tentatively extinguishes the fire immediately after ignition. it can.
　リン酸エステル化合物は特に限定されないが、縮合リン酸エステル化合物が好適である。 The phosphoric acid ester compound is not particularly limited, but a condensed phosphoric acid ester compound is suitable.
　縮合リン酸エステル化合物としては、芳香族縮合リン酸エステル化合物や含ハロゲン縮合リン酸エステル化合物が挙げられるが、芳香族縮合リン酸エステル化合物が好ましい。 Examples of the condensed phosphoric acid ester compound include an aromatic condensed phosphoric acid ester compound and a halogen-containing condensed phosphoric acid ester compound, but an aromatic condensed phosphoric acid ester compound is preferable.
　芳香族縮合リン酸エステル化合物としては、ＣＲ－７３３Ｓ、ＣＲ－７４１（いずれも大八化学工業株式会社製）を例示することができる。 Examples of the aromatic condensed phosphoric acid ester compound include CR-733S and CR-741 (both manufactured by Daihachi Chemical Industry Co., Ltd.).
　含ハロゲン縮合リン酸エステル化合物としては、ＣＲ－５０４Ｌ（大八化学工業株式会社製）を例示することができる。 As the halogen-containing condensed phosphoric acid ester compound, CR-504L (manufactured by Daihachi Chemical Industry Co., Ltd.) can be exemplified.
　樹脂とリン酸エステル化合物の割合は重量比で９１：９～４０：６０が好ましい。 The ratio of the resin to the phosphoric acid ester compound is preferably 91: 9 to 40:60 in terms of weight ratio.
　リン酸エステル化合物の割合が９未満であると、十分な難燃性が付与できず、引火の虞があり、引火すれば直後に鎮火しない虞があるからである。 This is because if the ratio of the phosphoric acid ester compound is less than 9, sufficient flame retardancy cannot be imparted and there is a risk of ignition, and if it ignites, there is a risk that the fire will not be extinguished immediately.
　また、リン酸エステル化合物の割合が６０よりも多いと、樹脂の濃度が低くなり過ぎて基材との密着性が低下するので乾燥塗膜が剥がれる虞があり、また、塗膜の強度が維持できない虞もある。加えて、リン酸エステル化合物によって比抵抗が上昇し、導電性が低下するからである。 Further, if the ratio of the phosphoric acid ester compound is more than 60, the concentration of the resin becomes too low and the adhesion to the substrate is lowered, so that the dry coating film may be peeled off and the strength of the coating film is maintained. It may not be possible. In addition, the phosphate ester compound increases the specific resistance and decreases the conductivity.
　本発明おける導電性ペーストは、固形樹脂を溶解したり、粘度を調整したりするために有機溶剤を含有する。 The conductive paste in the present invention contains an organic solvent in order to dissolve the solid resin and adjust the viscosity.
　本発明が含有する有機溶剤は特に限定されるものではないが、酢酸イソペンチル、ブチルカルビトールアセテート(ＢＣＡ)、ブチルカルビトール、ブチルセロソルブ、プロピレングリコールモノメチルエーテル、プロピレングリコールモノエチルエーテル、テキサノールを例示することができる。 The organic solvent contained in the present invention is not particularly limited, and examples thereof include isoamyl acetate, butyl carbitol acetate (BCA), butyl carbitol, butyl cellosolve, propylene glycol monomethyl ether, propylene glycol monoethyl ether, and texanol. Can be done.
　本発明の難燃性導電性ペーストが含有する固形分は４０～９０重量％が好ましく、更に好ましくは８０～９０重量％である。 The solid content contained in the flame-retardant conductive paste of the present invention is preferably 40 to 90% by weight, more preferably 80 to 90% by weight.
　固形分が４０重量％未満であると、粘度が低くなりすぎて、また、９０重量％を超えれば粘度が高くなりすぎて、均一な膜厚の塗膜を形成できない虞があるからである。 This is because if the solid content is less than 40% by weight, the viscosity becomes too low, and if it exceeds 90% by weight, the viscosity becomes too high, and a coating film having a uniform film thickness may not be formed.
　固形分におけるフレーク状銀粒子の含有量は８０～９５重量％が好ましく、より好ましくは、８８～９３重量％である。 The content of flaky silver particles in the solid content is preferably 80 to 95% by weight, more preferably 88 to 93% by weight.
　フレーク状銀粒子の含有量が８０重量％未満であると導電性が低下し、９５重量％を超えて含有すれば、樹脂が少なくなり過ぎて乾燥塗膜の強度が低下するのでいずれも好ましくない。 If the content of the flake-shaped silver particles is less than 80% by weight, the conductivity is lowered, and if the content is more than 95% by weight, the amount of resin is too small and the strength of the dry coating film is lowered, which is not preferable. ..
　本発明における難燃性導電性ペーストの粘度は２０～３００ｄＰａ・ｓが好ましい。２０ｄＰａ・ｓ未満、又は、３００ｄＰａ・ｓを超えると均一な膜厚の塗膜が形成できない虞があるからである。 The viscosity of the flame-retardant conductive paste in the present invention is preferably 20 to 300 dPa · s. This is because if it is less than 20 dPa · s or exceeds 300 dPa · s, a coating film having a uniform film thickness may not be formed.
　また、粘度が３００ｄＰａ・ｓを超えると、作業効率が悪くなる虞がある。 Further, if the viscosity exceeds 300 dPa · s, the work efficiency may deteriorate.
　粘度は、回転式粘度計を用いて測定することができる。 Viscosity can be measured using a rotary viscometer.
　本発明におけるチクソ値は１．５～２．５が好ましい。
　１．５未満、又は、２．５を超えると均一な膜厚の塗膜が形成できない虞があるからである。 The thixo value in the present invention is preferably 1.5 to 2.5.
This is because if it is less than 1.5 or more than 2.5, a coating film having a uniform film thickness may not be formed.
　本発明におけるチクソ値とは、２５℃における１ｒｐｍと１０ｒｐｍの各粘度（ｄＰａ・ｓ）を測定し、［式２］に算入して得ることができる。 The chixo value in the present invention can be obtained by measuring each viscosity (dPa · s) of 1 rpm and 10 rpm at 25 ° C. and incorporating it into [Equation 2].
［式２］　１ｒｐｍ粘度(ｄＰａ・ｓ)／１０ｒｐｍ粘度(ｄＰａ・ｓ) [Equation 2] 1 rpm viscosity (dPa · s) / 10 rpm viscosity (dPa · s)
　本発明における難燃性導電性ペーストの乾燥塗膜の比抵抗は２．５×１０－４Ω・ｃｍ以下であることが好ましい。コンデンサの電極に使用できるからである。 The specific resistance of the dry coating film of the flame-retardant conductive paste in the present invention is preferably 2.5 × 10 -4 Ω · cm or less. This is because it can be used as an electrode of a capacitor.
　乾燥塗膜の比抵抗は、硬化させた塗膜の抵抗値（Ω）を４端子法によって抵抗計で測定した後、下記［式３］にて算出する。 The specific resistance of the dried coating film is calculated by the following [Equation 3] after measuring the resistance value (Ω) of the cured coating film with a resistance meter by the 4-terminal method.
［式３］　抵抗値(Ω)×断面積(ｃｍ２)／長さ(ｃｍ) [Equation 3] Resistance value (Ω) x cross-sectional area (cm 2 ) / length (cm)
　本発明における難燃性導電性ペーストは、フレーク状銀粒子、樹脂、リン酸エステル化合物及び有機溶剤を擂潰機で３０～６０分混錬し、粘度を調整し作製することができる。
　また、市販の導電性ペーストに所望の濃度になるようにリン酸エステル化合物を添加し、３～５分混錬して作製してもよい。 The flame-retardant conductive paste in the present invention can be prepared by kneading flaky silver particles, a resin, a phosphoric acid ester compound and an organic solvent with a grinder for 30 to 60 minutes to adjust the viscosity.
Alternatively, a phosphoric acid ester compound may be added to a commercially available conductive paste to a desired concentration and kneaded for 3 to 5 minutes to prepare the paste.
　本発明における難燃性導電性ペーストは、下処理されたタンタルやアルミ素子上に塗布し、１００～１５０℃で１５～３０分加熱するか、樹脂の種類により、紫外線や可視光線の照射で硬化させることで電極を形成させることができる。 The flame-retardant conductive paste in the present invention is applied onto a prepared tantalum or aluminum element and heated at 100 to 150 ° C. for 15 to 30 minutes, or cured by irradiation with ultraviolet rays or visible light depending on the type of resin. The electrode can be formed by allowing the electrode to be formed.
　本発明の実施例を以下に示すが、本発明はこれに限定されない。 Examples of the present invention are shown below, but the present invention is not limited thereto.
　フレーク状銀粒子（平均粒径（ｄ５０）７μm、比表面積０．３ｍ２/ｇ、アスペクト比１０）とフェノキシ樹脂及びブチルカルビトールアセテート（ＢＣＡ）とを混ぜ合わせ、３本ロールミル（アイメックス株式会社製）で均一に混錬して導電性ペーストを得た。 Flake-shaped silver particles (average particle size (d50) 7 μm, specific surface area 0.3 m 2 / g, aspect ratio 10) are mixed with phenoxy resin and butyl carbitol acetate (BCA), and a 3-roll mill (manufactured by Imex Co., Ltd.) ) Was uniformly kneaded to obtain a conductive paste.
　得られた導電性ペーストは、フレーク状銀粒子８０重量％、フェノキシ樹脂５重量％、ブチルカルビトールアセテート１５重量％である。 The obtained conductive paste is 80% by weight of flake-shaped silver particles, 5% by weight of phenoxy resin, and 15% by weight of butyl carbitol acetate.
　作製した導電性ペーストと、芳香族縮合リン酸エステル化合物ＣＲ－７３３Ｓ（比重１．３、粘度６００ｍＰａ・ｓ）、又は、ＣＲ－７４１（４０℃における比重１．３、粘度２３００ｍＰａ・ｓ）、又は、含ハロゲン縮合リン酸エステル化合物ＣＲ－５０４Ｌ（比重１．３、粘度１０００ｍＰａ・ｓ）を表１～３に示す通り混合し、混錬機ＡＲＥ－３１０（株式会社シンキー製）にて１分間混錬して実施例及び比較例の各導電性ペーストを作製した。 The prepared conductive paste and the aromatic condensed phosphoric acid ester compound CR-733S (specific gravity 1.3, viscosity 600 mPa · s) or CR-741 (specific gravity 1.3 at 40 ° C., viscosity 2300 mPa · s), or , Halogen-containing condensed phosphoric acid ester compound CR-504L (specific gravity 1.3, viscosity 1000 mPa · s) is mixed as shown in Tables 1 to 3, and mixed in a kneader ARE-310 (manufactured by Shinky Co., Ltd.) for 1 minute. Each conductive paste of Example and Comparative Example was prepared by smelting.
　各導電性ペーストの難燃剤の含有量については樹脂１００重量％に対する添加量（ｐｈｒ）で表すことがある。 The content of the flame retardant in each conductive paste may be expressed as the amount added (phr) with respect to 100% by weight of the resin.
（着火試験）
　フッ素コーティングした基材に実施例及び比較例の各導電性ペーストを約１７０μｍの厚みで塗布し、オーブンにて１５０℃で３０分乾燥させた。 (Ignition test)
Each of the conductive pastes of Examples and Comparative Examples was applied to a fluorine-coated base material to a thickness of about 170 μm, and dried in an oven at 150 ° C. for 30 minutes.
　残存する有機溶剤のバラツキを解消するために、乾燥塗膜を基材から剥離し、剥離面を上にして、再度１５０℃で３０分乾燥させた。 In order to eliminate the variation in the remaining organic solvent, the dry coating film was peeled from the base material, and the peeled surface was turned up and dried again at 150 ° C. for 30 minutes.
　その後、短冊状にカットした乾燥塗膜の端部にライターで点火し着火の有無及び鎮火の有無を観察した。 After that, the edge of the dry coating film cut into strips was ignited with a lighter, and the presence or absence of ignition and the presence or absence of fire extinguishing were observed.
　着火しなかったものを◎、着火後１秒以内に鎮火したものを〇、着火後３秒以内に鎮火したものを△、鎮火せずに乾燥塗膜全体が燃焼したものを×として評価した。
　なお、時間はライターを離した時点から測定開始した値である。 Those that did not ignite were evaluated as ⊚, those that extinguished within 1 second after ignition were evaluated as 〇, those that extinguished within 3 seconds after ignition were evaluated as Δ, and those that burned the entire dry coating film without extinguishing were evaluated as ×.
The time is a value at which the measurement is started when the lighter is released.
（比抵抗）
　乾燥塗膜の比抵抗は、ガラス基板上に４ｍｍ幅×４０ｍｍ長さ×２０μｍ厚さの塗膜を形成した後、４端子法で抵抗計ミリオームハイテスタ３５４０－０２（日置電機株式会社製）にて測定し、抵抗値（Ω）から前記［式３］にて、体積固有抵抗（比抵抗／Ω・ｃｍ）を算出した。 (Specific resistance)
The resistivity of the dry coating film is as follows: After forming a coating film having a width of 4 mm, a length of 40 mm, and a thickness of 20 μm on a glass substrate, a resistivity meter Millioam High Tester 3540-02 (manufactured by Hioki Denki Co., Ltd.) is used by the 4-terminal method. The volume resistivity (specific resistance / Ω · cm) was calculated from the resistance value (Ω) by the above [Equation 3].
（粘度）
　各導電性ペーストの２５℃における粘度（ｄＰａ・ｓ）をビスコテスターＶＴ－０４(リオン株式会社製)にて測定した。 (viscosity)
The viscosity (dPa · s) of each conductive paste at 25 ° C. was measured with a Viscotester VT-04 (manufactured by Rion Co., Ltd.).
（チクソ値）
　各導電性ペーストの２５℃における１ｒｐｍ及び１０ｒｐｍの粘度（ｄＰａ・ｓ）をコーンプレート型粘度計ＨＢＤＶ－IIIスピンドルＣＰＥ－４２(ブルックフィールド社製)にて測定した後、前記［式２］にてチクソ値を算出した。 (Chixo value)
After measuring the viscosities (dPa · s) of each conductive paste at 25 ° C. at 1 rpm and 10 rpm with a cone plate type viscometer HBDV-III spindle CPE-42 (manufactured by Brookfield), the above [Formula 2] was used. The viscosity value was calculated.
（剥離試験）
　比抵抗を測定した後のガラス基板上の乾燥塗膜の上にセロハンテープ（セキスイ株式会社製）を張り付けた後に剥がし、剥がしたセロハンテープに乾燥塗膜が付着せず、全く剥離が観察されなかったものを〇、乾燥塗膜の一部がセロハンテープに付着し、剥離が観察されたものを△、乾燥塗膜の全部がセロハンテープに付着して、完全に剥離したものを×として評価した。 (Peeling test)
After measuring the specific resistance, the cellophane tape (manufactured by Sekisui Co., Ltd.) was attached on the dry coating film on the glass substrate and then peeled off. The dry coating film did not adhere to the peeled cellophane tape, and no peeling was observed. Those that were evaluated as 〇, those in which part of the dry coating film adhered to the cellophane tape and peeling was observed were evaluated as Δ, and those in which all of the dry coating film adhered to the cellophane tape and completely peeled off were evaluated as ×. ..
　結果を表１～表３に示す。
　なお、表１はＣＲ－７３３Ｓ、表２はＣＲ－５０４Ｌ、表３はＣＲ－７４１の各難燃剤を使用した。 The results are shown in Tables 1 to 3.
The flame retardants of CR-733S in Table 1, CR-504L in Table 2, and CR-741 in Table 3 were used.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
　表１～表３に示した通り、本発明における導電性ペーストは、難燃性が高いので、ライターの火を近づけても着火しないか、又は、着火しても直後に鎮火し、また、乾燥塗膜の比抵抗は低く、加えて、剥離し難い難燃性導電性ペーストである。 As shown in Tables 1 to 3, the conductive paste in the present invention has high flame retardancy, so that it does not ignite even if the lighter's fire is brought close to it, or it is extinguished immediately after ignition and dried. The specific resistance of the coating film is low, and in addition, it is a flame-retardant conductive paste that is difficult to peel off.
　本発明は、乾燥塗膜の導電性に優れ、また、基材との密着性が高くて剥離し難い導電性ペーストであるため、コンデンサの電極に好適に使用でき、また、近辺で出火があったとしても引火しないか、又は、引火しても直後に鎮火するという高い難燃性を備えるため、コンデンサの電極に使用した場合には、短絡出火によるコンデンサの燃焼を防止することができる難燃性導電性ペーストである。
　したがって、本発明は産業上の利用可能性の高い発明である。 INDUSTRIAL APPLICABILITY The present invention is a conductive paste that has excellent conductivity of a dry coating film and has high adhesion to a substrate and is difficult to peel off. Therefore, it can be suitably used for a capacitor electrode, and a fire may occur in the vicinity. Even if it does, it does not ignite, or even if it ignites, it has a high flame retardancy that it extinguishes immediately afterwards. Therefore, when used for a capacitor electrode, it is possible to prevent combustion of the capacitor due to a short-circuit fire. It is a conductive and conductive paste.
Therefore, the present invention is an invention with high industrial applicability.

Claims (5)

  1. フレーク状銀粒子と樹脂と難燃剤と有機溶剤を含有する難燃性導電性ペーストであって、前記フレーク状銀粒子と前記樹脂と前記難燃剤からなる固形分が４０～９０重量％であり、前記固形分における前記フレーク状銀粒子の含有量が８０～９５重量％であり、前記樹脂対前記難燃剤の重量比が９１：９～４０：６０であり、前記難燃剤がリン酸エステル化合物である難燃性導電性ペースト。 A flame-retardant conductive paste containing flake-shaped silver particles, a resin, a flame retardant, and an organic solvent, wherein the solid content of the flake-shaped silver particles, the resin, and the flame retardant is 40 to 90% by weight. The content of the flake-shaped silver particles in the solid content is 80 to 95% by weight, the weight ratio of the resin to the flame retardant is 91: 9 to 40:60, and the flame retardant is a phosphoric acid ester compound. A flame retardant conductive paste.
  2. 前記リン酸エステル化合物が縮合リン酸エステル化合物である請求項１記載の難燃性導電性ペースト。 The flame-retardant conductive paste according to claim 1, wherein the phosphoric acid ester compound is a condensed phosphoric acid ester compound.
  3. 前記難燃性導電性ペーストのチクソ値が１．５～２．５である請求項１又は２記載の難燃性導電性ペースト。 The flame-retardant conductive paste according to claim 1 or 2, wherein the chixo value of the flame-retardant conductive paste is 1.5 to 2.5.
  4. 前記難燃性導電性ペーストの比抵抗が２．５×１０－４Ω・ｃｍ以下である請求項１乃至３いずれか記載の難燃性導電性ペースト。 The flame-retardant conductive paste according to any one of claims 1 to 3, wherein the specific resistance of the flame-retardant conductive paste is 2.5 × 10 -4 Ω · cm or less.
  5. 銀粒子と樹脂と難燃剤と有機溶剤とを混錬して製造する請求項１乃至４いずれか記載の難燃性導電性ペーストの製造方法。 The method for producing a flame-retardant conductive paste according to any one of claims 1 to 4, which is produced by kneading silver particles, a resin, a flame retardant, and an organic solvent.
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Publication number Priority date Publication date Assignee Title
JP2001502375A (en) * 1996-10-22 2001-02-20 シルバーライン リミテッド Metal pigment component
JP2004221005A (en) * 2003-01-17 2004-08-05 Toyobo Co Ltd Conductive paste
JP2017162776A (en) * 2016-03-11 2017-09-14 福田金属箔粉工業株式会社 Conductive paste
CN108003771A (en) * 2017-12-19 2018-05-08 杭州湘隽阻燃科技有限公司 A kind of halogen-free flameproof electromagnetic shielding material and preparation method and application
CN108117727A (en) * 2017-12-19 2018-06-05 罗洪梅 A kind of heat-resisting low warpage conduction PC/PCT alloys of high-rigidity high-ductility and preparation method thereof

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001502375A (en) * 1996-10-22 2001-02-20 シルバーライン リミテッド Metal pigment component
JP2004221005A (en) * 2003-01-17 2004-08-05 Toyobo Co Ltd Conductive paste
JP2017162776A (en) * 2016-03-11 2017-09-14 福田金属箔粉工業株式会社 Conductive paste
CN108003771A (en) * 2017-12-19 2018-05-08 杭州湘隽阻燃科技有限公司 A kind of halogen-free flameproof electromagnetic shielding material and preparation method and application
CN108117727A (en) * 2017-12-19 2018-06-05 罗洪梅 A kind of heat-resisting low warpage conduction PC/PCT alloys of high-rigidity high-ductility and preparation method thereof

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