Thermosetting electroconductive resin composition, and method for producing electronic component

Abstract

A thermosetting electroconductive resin composition characterized by containing an electroconductive powder including a base metal, a thermosetting silicone resin having a hydroxyl group, and at least one of an amine-based additive and an acid-based additive. According to the present invention, it is possible to provide a thermosetting electroconductive resin composition for forming an electrode of an electronic component, the thermosetting electroconductive resin composition having high viscosity stability, suppressing any decrease in electroconductivity (the electroconductivity is excellent), and being capable of forming an electroconductive resin layer having exceptional moisture resistance, even when the thermosetting electroconductive resin composition contains a thermosetting silicone resin having a hydroxyl group and an electroconductive powder including a base metal such as Cu.

Description

Thermosetting conductive resin composition and method for manufacturing electronic components

[0001] The present invention relates to a thermosetting conductive resin composition for forming electrodes of electronic components, for producing electronic components by forming electrodes on an electrode-forming body for electronic components, such as a laminate for multilayer electronic components or an electrode-forming body for solid electrolytic capacitors.The present invention also relates to a method for producing electronic components by forming electrodes on an electrode-forming body for electronic components, such as a laminate for multilayer electronic components or an electrode-forming body for solid electrolytic capacitors.

[0002] In recent years, electronic devices have come to be used in harsher environments than before, and therefore electronic components mounted on electronic devices are also required to be able to withstand such harsh environments without breaking down.

[0003] Specifically, for example, even if a mobile device such as a smartphone is dropped, or an electronic device mounted in an automobile is subjected to vibrations while driving, high impact resistance is required so that cracks or interfacial peeling do not occur at the connection between the substrate and the electronic component, causing the electronic component to fall off from the substrate, or cracks do not occur in the electronic component itself.

[0004] Furthermore, since mobile devices and automobiles are sometimes exposed to high humidity environments, the electronic components installed in these devices and automobiles must have high moisture resistance to prevent moisture from entering the interior.

[0005] Here, Patent Document 1 discloses a composition that does not contain an epoxy resin and is composed of a gel-like silicone rubber (polydimethylsiloxane) and a conductive powder, and describes that by using this composition to form a conductive resin layer on the outer surface of the external electrode of a multilayer ceramic capacitor, the external electrode has moisture resistance in the sense that it can effectively block the penetration of a plating solution, and also has a bending strength that is even better than when a composition containing an epoxy resin is used.

[0006] JP 2014-135463 A

[0007] As described above, Patent Document 1 describes that a certain level of moisture resistance can be achieved by using silicone rubber. However, silicone rubber and silicone resin have very high insulating properties and are therefore often used for insulating purposes, and when used for conductive purposes, it is often difficult to achieve conductivity.

[0008] Therefore, the inventors conducted extensive research and found that forming a conductive resin layer using a thermosetting conductive resin composition containing a thermosetting silicone resin having a hydroxyl group can achieve both moisture resistance and conductivity. However, the inventors discovered that when a conductive powder containing a base metal such as Cu is used as the conductive powder in the composition, the viscosity of the conductive resin composition may increase over time, and the conductivity may decrease (good conductivity may not be obtained).

[0009] Therefore, an object of the present invention is to provide a conductive resin composition for forming electrodes of electronic components, which is capable of forming a conductive resin layer that has high viscosity stability, is inhibited from decreasing in conductivity (has good conductivity), and is excellent in moisture resistance, even when it contains a thermosetting silicone resin having hydroxyl groups and a conductive powder that contains a base metal such as Cu.

[0010] As a result of extensive research to solve the above problems, the present inventors have discovered that by including at least one additive selected from an amine-based additive and an acid-based additive in addition to a conductive powder containing a base metal such as Cu and a thermosetting silicone resin having a hydroxyl group, it is possible to obtain a thermosetting conductive resin composition that is capable of forming a conductive resin layer that has high viscosity stability, is inhibited from decreasing in conductivity (has good conductivity), and is excellent in moisture resistance, and have thereby completed the present invention.

[0011] That is, the present invention (1) provides a thermosetting conductive resin composition comprising: a conductive powder containing a base metal; a thermosetting silicone resin having a hydroxyl group; and at least one of an amine-based additive and an acid-based additive.

[0012] The present invention (2) also provides the thermosetting conductive resin composition of (1), wherein the molecular weight of the amine-based additive or the acid-based additive is in the range of 30 or more and 2,000 or less.

[0013] The present invention (3) also provides the thermosetting conductive resin composition according to (1) or (2), characterized in that the boiling point Tb or the 90% mass loss temperature Td90 of the amine-based additive or the acid-based additive under 1 atmosphere is 80°C or higher and 400°C or lower.

[0014] The present invention (4) also provides the thermosetting conductive resin composition according to any one of (1) to (3), wherein the amine additive contains at least one of a secondary amine and a tertiary amine.

[0015] The present invention (5) also provides the thermosetting conductive resin composition according to any one of (1) to (4), wherein the acid additive contains a dicarboxylic acid.

[0016] The present invention (6) also provides the thermosetting conductive resin composition of (1), characterized in that the content of the amine-based additive is 0.6 parts by mass or more and 10.0 parts by mass or less relative to 100 parts by mass of the thermosetting silicone resin having a hydroxyl group, and / or the content of the acid-based additive is 0.1 parts by mass or more and 1.6 parts by mass or less relative to 100 parts by mass of the conductive powder containing a base metal.

[0017] The present invention (7) also provides a method for producing an electronic component, comprising: a preparation step of preparing an electronic component electrode-forming body; and an electrode-forming step of forming an electrode on the outer surface of the electronic component electrode-forming body, wherein in the electrode-forming step, a thermosetting conductive resin composition according to any one of (1) to (6) is applied to the electronic component electrode-forming body, and then the thermosetting conductive resin composition is cured to form a conductive resin layer on the electronic component electrode-forming body.

[0018] According to the present invention, it is possible to provide a thermosetting conductive resin composition for forming electrodes of electronic components, which is capable of forming a conductive resin layer that has high viscosity stability, is inhibited from decreasing in conductivity (has good conductivity), and is excellent in moisture resistance, even when it contains a thermosetting silicone resin having hydroxyl groups and a conductive powder that contains a base metal such as Cu.

[0019] The thermosetting conductive resin composition of the present invention is a thermosetting conductive resin composition containing a conductive powder containing a base metal, a thermosetting silicone resin having hydroxyl groups, and at least one of an amine additive and an acid additive. This allows for the formation of a conductive resin layer with excellent moisture resistance and conductivity, and also provides excellent viscosity stability. While the reason for this effect is unclear, the inventors speculate as follows: When the composition contains a thermosetting silicone resin having hydroxyl groups and a conductive powder containing a base metal such as Cu, the reaction between the base metal such as Cu and the hydroxyl groups increases the viscosity of the composition over time and inhibits thermal curing. The presence of the amine additive in the composition allows the amine additive to coordinate with the hydroxyl groups of the resin, protecting the hydroxyl groups from the base metal such as Cu, thereby suppressing the increase in viscosity of the composition over time and inhibiting curing inhibition, thereby suppressing a decrease in the conductivity of the resulting conductive resin layer (ensuring good conductivity). Furthermore, the presence of an acid-based additive in the composition causes the acid-based additive to bond to the surface of the conductive powder, preventing contact between base metals such as Cu and the hydroxyl groups of the thermosetting silicone resin. This in turn suppresses an increase in viscosity of the composition over time, and also suppresses inhibition of curing, thereby suppressing a decrease in the conductivity of the resulting conductive resin layer (ensuring good conductivity).

[0020] The thermosetting conductive resin composition of the present invention is a thermosetting conductive resin composition that is cured by heating to form a cured film (conductive resin layer). The heating temperature is not particularly limited, but examples include a range of 150°C to 300°C, and a range of 180°C to 250°C.

[0021] The thermosetting conductive resin composition of the present invention contains a conductive powder. The thermosetting conductive resin composition of the present invention contains a conductive powder containing at least a base metal as the conductive powder. Examples of conductive powders containing a base metal include base metal powder, base metal alloy powders composed of an alloy of two or more base metals, precious metal-coated base metal powders in which the surface of a base metal powder is coated with a precious metal, and alloy powders of a base metal and a precious metal. Examples of conductive powders containing a base metal include copper powder, silver-coated copper powder, copper alloy powder, silver-lead alloy powder, tin powder, nickel powder, silver-coated nickel powder, copper-nickel alloy powder, iron powder, zinc powder, and aluminum powder. Silver powder is prone to ion migration, so a powder that does not contain silver, i.e., a base metal powder, particularly copper powder, is preferred because it is less susceptible to ion migration. Furthermore, from the perspective of low cost, silver-coated copper powder, copper powder, and copper alloy powders that do not contain expensive metal components such as precious metals or rare metals are preferred as conductive powders containing a base metal, with copper powder being particularly preferred. From the perspective of excellent conductivity, silver-coated copper powder is preferred as the conductive powder containing a base metal. For the silver-coated copper powder, it is sufficient that silver coats at least a portion of the copper powder surface. As described above, the thermosetting conductive resin composition of the present invention preferably contains Cu for various reasons. On the other hand, in a composition containing a thermosetting silicone resin having hydroxyl groups, problems of increased viscosity and decreased conductivity are likely to occur when a conductive powder containing a base metal is used. These problems are particularly likely to occur when a conductive powder containing Cu is used. In the thermosetting conductive resin composition of the present invention, the use of an amine-based additive or an acid-based additive can solve the problems that arise when a thermosetting silicone resin having hydroxyl groups is combined with a conductive powder containing a base metal. In particular, using Cu as the base metal can maximize the advantages of the conductive powder containing Cu while also solving the problems that arise when a thermosetting silicone resin having hydroxyl groups is combined with a conductive powder containing Cu. That is, in the present invention, the effects of the present invention are particularly pronounced when a conductive powder containing Cu, a thermosetting silicone resin having hydroxyl groups, and at least one of an amine-based additive and an acid-based additive are combined.In this specification, "base metal" refers to copper or metals with a greater ionization tendency than copper, such as copper, iron, nickel, aluminum, lead, zinc, and tin, and "noble metal" refers to metals with a lesser ionization tendency than copper, such as gold, silver, and platinum.

[0022] In the thermosetting conductive resin composition of the present invention, the shape of the conductive powder is not particularly limited, and examples thereof include a spherical shape and a flake shape. However, a flake shape is preferred in terms of excellent conductivity and adhesiveness.

[0023] The thermosetting conductive resin composition of the present invention can further contain other conductive powders in addition to the conductive powder containing a base metal described above. That is, the thermosetting conductive resin composition of the present invention may contain only a conductive powder containing a base metal as the conductive powder, or may contain a conductive powder containing a base metal and a conductive powder containing a precious metal. The shape of the other conductive powder is not particularly limited, and examples include spherical and flaky shapes. However, flaky shapes are preferred in terms of excellent conductivity and adhesiveness.

[0024] In the thermosetting conductive resin composition of the present invention, the content of the flaky conductive powder relative to the total conductive powder is preferably 20.0 mass% or more, more preferably 40.0 mass% or more, and particularly preferably 60.0 mass% or more. When the content of the flaky conductive powder relative to the total conductive powder is within the above range, the conductivity and adhesiveness of the obtained conductive resin layer are improved.

[0025] The aspect ratio of the flaky conductive powder is preferably 1.5 to 50.0, more preferably 2.0 to 30.0, and particularly preferably 5.0 to 20.0. When the aspect ratio of the flaky conductive powder is within the above range, the conductivity and adhesiveness of the resulting conductive resin layer are improved. In the present invention, the major axis and thickness of 50 randomly selected conductive powder particles were measured in scanning electron microscope (SEM) image observation, and the average value of the ratio of the major axis to the thickness (major axis / thickness) was taken as the aspect ratio of the flaky conductive powder.

[0026] The number-average particle diameter of the flaky conductive powder, as measured using a scanning electron microscope (SEM), is preferably 0.1 to 20.0 μm, more preferably 0.3 to 15.0 μm, even more preferably 0.5 to 10.0 μm, and particularly preferably 1.0 to 5.0 μm. Having the number-average particle diameter of the flaky conductive powder within the above range enhances the conductivity and adhesiveness of the resulting conductive resin layer. In the present invention, the major axes of 50 randomly selected conductive powder particles were measured in SEM (scanning electron microscope) image observation, and the average value was used as the number-average particle diameter of the flaky conductive powder.

[0027] The specific surface area of ​​the flake-shaped conductive powder is preferably 0.5 to 5.0 m ２ / g, particularly preferably 0.6 to 4.0 m ２ When the specific surface area of ​​the flaky conductive powder is within the above range, the resulting conductive resin layer has high conductivity and adhesiveness.

[0028] The volume-based cumulative 50% particle diameter (D ５０ ) is preferably 0.01 to 7.0 μm, particularly preferably 0.03 to 5.0 μm. ５０ When D is in the above range, the resulting conductive resin layer has high conductivity and adhesiveness. ５０ Regarding the particle size distribution, the 50% value (D ５０ ) was sought.

[0029] The specific surface area of ​​the spherical conductive powder is preferably 0.2 to 3.0 m ２ / g, particularly preferably 0.3 to 2.5 m ２ When the specific surface area of ​​the spherical conductive powder is within the above range, the resulting conductive resin layer has high conductivity and adhesiveness.

[0030] The thermosetting conductive resin composition of the present invention contains a resin binder. The thermosetting conductive resin composition of the present invention contains, as the resin binder, a thermosetting silicone resin having at least a hydroxyl group. The thermosetting silicone resin having a hydroxyl group is preferably a condensation-type thermosetting silicone resin that has a hydroxyl group and cures by undergoing a condensation reaction upon heating, more preferably a dehydration-condensation-type silicone resin that has a hydroxyl group and cures by undergoing a dehydration-condensation reaction upon heating, and particularly preferably a dehydration-condensation-type thermosetting silicone resin that has a hydroxyl group (silanol group) bonded to a silicon atom and cures by undergoing a dehydration-condensation reaction upon heating.

[0031] The content of the thermosetting silicone resin having a hydroxyl group relative to the total resin binder contained in the thermosetting conductive resin composition of the present invention is preferably 25.0 mass% or more, more preferably 30.0 mass% or more, more preferably 40.0 mass% or more, more preferably 50.0 mass% or more, more preferably 60.0 mass% or more, more preferably 70.0 mass% or more, more preferably 80.0 mass% or more, more preferably 90.0 mass% or more, and particularly preferably 95.0 mass% or more. When the thermosetting conductive resin composition contains a thermosetting silicone resin having a hydroxyl group in the above range, the moisture resistance of the conductive resin layer is increased, and the effect of reducing the resistivity and suppressing the viscosity increase caused by using an amine-based additive or an acid-based additive is enhanced.

[0032] A thermosetting silicone resin having a hydroxyl group cures by heating without the use of a curing agent or catalyst. The preferred type of heat-curing is a condensation-curing type, in which a condensation reaction proceeds when heated to cure the resin. A dehydration-condensation type, in which a dehydration-condensation reaction proceeds when heated to cure the resin, is particularly preferred.

[0033] The position and number of hydroxyl groups in the thermosetting silicone resin having hydroxyl groups are not particularly limited, and can be, for example, at one end of the polymer, both ends of the polymer, or the side chain of the polymer. From the viewpoint of excellent conductivity, it is preferable to have multiple hydroxyl groups at least on the side chain. The hydroxyl group may be bonded to a silicon atom, or to an atom other than a silicon atom (e.g., a carbon atom). In this specification, the OH group bonded to Si in a silanol group is also referred to as a hydroxyl group.

[0034] The main skeleton (main chain) of the thermosetting silicone resin having a hydroxyl group may contain a siloxane unit, and examples thereof include a polymer (polysiloxane) consisting of only siloxane units and a copolymer containing siloxane units. Examples of the copolymer containing siloxane units include a copolymer of at least one of a monomer, oligomer, and polymer containing siloxane units and at least one of a monomer, oligomer, and polymer not containing siloxane units. These polymers and copolymers may be linear or branched.

[0035] The thermosetting silicone resin having a hydroxyl group may have a functional group other than a hydroxyl group on the side chain or end of the polymer, such as an alkenyl group, a hydrogensilyl group, a (meth)acryloyl group, an epoxy group, an amino group, a carbinol group, a mercapto group, a carboxy group, a phenol group, an aryl group, an alkyl group such as a methyl group, an aromatic group such as a phenyl group, etc. As the functional group of the thermosetting silicone resin, an alkyl group such as a methyl group and an aromatic group such as a phenyl group are preferred in terms of moisture resistance, a hydroxyl group is preferred in terms of conductivity, and an epoxy group is preferred in terms of adhesiveness.

[0036] The thermosetting silicone resin having a hydroxyl group may be a modified resin in which various oligomers or polymers are introduced (grafted) into the side chains or ends of the polymer, or may be a crosslinked resin in which resins are crosslinked with each other.

[0037] The molecular weight (weight average molecular weight Mw) of the hydroxyl group-containing thermosetting silicone resin is not particularly limited, but is preferably 1,000 to 300,000, and particularly preferably 2,000 to 200,000.

[0038] The thermosetting conductive resin composition of the present invention may further contain a curing agent or a catalyst, for example, platinum-based, titanium-based, aluminum-based, zinc-based, iron-based, or phosphoric acid-based curing agents or catalysts.

[0039] The thermosetting conductive resin composition of the present invention may contain a resin binder other than the thermosetting silicone resin having a hydroxyl group, as long as the effects of the present invention are not impaired. The resin binder other than the thermosetting silicone resin having a hydroxyl group may be a thermosetting resin or a thermoplastic resin. Examples of the resin binder other than the thermosetting silicone resin having a hydroxyl group include cellulose-based resins such as ethyl cellulose, acetal-based resins such as polyvinyl acetal resin, polyimide resins, polyamide resins, polyamideimide resins, epoxy resins, acrylic resins, butadiene-based resins such as polybutadiene, (meth)acrylic resins, styrene resins, phenolic resins, alkyd resins, polyurethane resins, and silicone resins other than the thermosetting silicone resin having a hydroxyl group.

[0040] The content of the resin binder in the thermosetting conductive resin composition of the present invention is preferably 3.0 to 30.0 parts by mass, more preferably 3.0 to 28.0 parts by mass, more preferably 3.0 to 25.0 parts by mass, more preferably 5.0 to 25.0 parts by mass, more preferably 7.0 to 23.0 parts by mass, and particularly preferably 11.0 to 20.0 parts by mass, per 100.0 parts by mass of the conductive powder. Having the resin binder content within the above range makes it easy to obtain a conductive resin layer with excellent conductivity and adhesiveness. Furthermore, excellent printability is likely to be achieved when the thermosetting conductive resin composition is applied to an electrode-forming body.

[0041] The thermosetting conductive resin composition of the present invention contains at least one additive selected from the group consisting of an amine-based additive and an acid-based additive. By including an amine-based additive and / or an acid-based additive in the thermosetting conductive resin composition of the present invention, viscosity stability can be improved and a decrease in conductivity can be suppressed (good conductivity can be obtained), even when the thermosetting conductive resin composition contains a thermosetting silicone resin having a hydroxyl group and a conductive powder containing a base metal. The use of an amine-based additive as an additive is particularly preferred, as it makes it easier to achieve the effects of the present invention. Furthermore, the use of an amine-based additive and an acid-based additive in combination as additives is also preferred, as it makes it easier to achieve the effects of the present invention.

[0042] The amine additive is not particularly limited, and examples thereof include primary amines, secondary amines, and tertiary amines. In particular, when the amine additive is a secondary amine or a tertiary amine, the effects of the present invention can be more suitably obtained, and therefore it is preferable, and among these, secondary amines are preferable.

[0043] The molecular weight of the amine additive is preferably in the range of 10 to 5000, more preferably in the range of 20 to 3000, even more preferably in the range of 30 to 2000, still more preferably in the range of 40 to 1000, even more preferably in the range of 50 to 500, still more preferably in the range of 80 to 350, and particularly preferably in the range of 100 to 300. When the molecular weight of the amine additive is in the above range, the effects of the present invention can be more suitably obtained.

[0044] The number of carbon atoms in the amine additive is preferably 6 or more and 20 or less, and particularly preferably 7 or more and 18 or less, so that the effects of the present invention can be more suitably obtained.

[0045] The pKa of the amine additive measured in water at 25° C. is preferably 7.5 or more and 12.0 or less, whereby the effects of the present invention can be more suitably obtained.

[0046] The boiling point Tb or 90% mass loss temperature Td90 of the amine additive at 1 atmosphere is preferably from −100° C. to +30° C., more preferably from −75° C. to +20° C., and particularly preferably from −50° C. to +10° C., when the curing temperature of the conductive resin composition is used as the reference temperature. The boiling point Tb or 90% mass loss temperature Td90 of the amine additive at 1 atmosphere is preferably from 80° C. to 400° C., more preferably from 80° C. to 350° C., more preferably from 80° C. to 300° C., still more preferably from 100° C. to 250° C., and particularly preferably from 120° C. to 230° C. When the boiling point Tb or 90% mass loss temperature Td90 of the amine additive at 1 atmosphere is within the above range, the additive acts in the conductive resin composition until just before curing, making it easier to achieve the effects of the present invention. Furthermore, when the boiling point Tb or 90% mass loss temperature Td90 of the amine additive at 1 atmosphere is within the above range, it is likely to vaporize or decompose before curing is complete, so it is less likely to interfere with curing and the effects of the present invention are more likely to be achieved. Furthermore, since it is less likely to remain in the cured film, the resulting conductive resin layer is more likely to have excellent conductivity and moisture resistance. In this specification, the "90% mass loss temperature Td90" refers to the temperature at which 90% mass loss occurs when heated at a heating rate of 10°C / min under conditions of 1 atmosphere and air atmosphere.

[0047] Examples of the amine additive include monoamines, diamines, and triamines, and the use of diamines and triamines is preferred because the effects of the present invention can be significantly achieved, and the use of diamines is particularly preferred because the effects of the present invention can be more significantly achieved. More specific examples of the amine additive include monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monopropylamine, dipropylamine, diisopropylamine, tripropylamine, monobutylamine, dibutylamine, tributylamine, monopentylamine, dipentylamine, tripentylamine, monohexylamine, dihexylamine, trihexylamine, monoheptylamine, diheptylamine, triheptylamine, monooctylamine, dioctylamine, dimethyloctylamine, trioctylamine, dimethylethylamine, diethanolamine, polyoxyethylene laurylamine, N-lauryldiethanolamine, 3- (2-ethylhexyloxy)propylamine, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane, poly(tetramethylene / 3-methyltetramethylene ether) glycol bis(4-aminobenzoate), polytetramethylene oxide-di-p-aminobenzoate, and triethanolamine are mentioned. When the amine additive contains at least one selected from dibutylamine, triethanolamine, diisopropylamine, dihexylamine, dimethyloctylamine, and polyoxyethylene laurylamine, the effects of the present invention can be more suitably obtained, which is preferable. In particular, when the amine additive contains at least one selected from dibutylamine, triethanolamine, and polyoxyethylene laurylamine, the effects of the present invention can be even more suitably obtained, which is preferable.

[0048] The acid additive is not particularly limited as long as it is an organic acid, and examples thereof include carboxylic acids such as monocarboxylic acids, dicarboxylic acids, and tricarboxylic acids. In particular, when the acid additive is a dicarboxylic acid, the effects of the present invention can be more suitably obtained, and therefore it is preferred. Examples of dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, octenylsuccinic acid, and octadecylbutanedioic acid. In particular, when the acid additive is octadecylbutanedioic acid, the effects of the present invention can be more suitably obtained, and therefore it is preferred.

[0049] The molecular weight of the acid-based additive is preferably in the range of 10 to 5000, more preferably in the range of 20 to 3000, even more preferably in the range of 30 to 2000, still more preferably in the range of 100 to 1000, and particularly preferably in the range of 250 to 750. When the molecular weight of the acid-based additive is in the above range, the effects of the present invention can be more suitably obtained.

[0050] The number of carbon atoms in the acid additive is preferably from 10 to 35, and particularly preferably from 15 to 25. This allows the effects of the present invention to be more suitably obtained.

[0051] The pKa of the acid additive measured in water at 25° C. is preferably 2.0 or more and 6.5 or less, whereby the effects of the present invention can be more suitably obtained.

[0052] The boiling point or 90% mass loss temperature Td90 of the acid-based additive at 1 atmosphere is preferably from −100° C. to +30° C., preferably from −75° C. to +20° C., and more preferably from −50° C. to +10° C., when the curing temperature of the conductive resin composition is used as the reference temperature. The boiling point Tb or 90% mass loss temperature Td90 of the acid-based additive at 1 atmosphere is preferably from 80° C. to 350° C., more preferably from 80° C. to 300° C., still more preferably from 100° C. to 250° C., and particularly preferably from 120° C. to 230° C. When the boiling point Tb or 90% mass loss temperature Td90 of the acid-based additive at 1 atmosphere is within the above range, the acid-based additive acts in the conductive resin composition until just before curing, making it easier to achieve the effects of the present invention. Furthermore, when the boiling point Tb or the 90% mass loss temperature Td90 of the acid-based additive at 1 atmosphere is within the above range, the acid-based additive is likely to vaporize or decompose before the completion of curing, so that the curing is less likely to be hindered and the effects of the present invention are more likely to be achieved. Furthermore, since the acid-based additive is less likely to remain in the film after curing, the resulting conductive resin layer is likely to have excellent conductivity and moisture resistance.

[0053] When the thermosetting conductive resin composition of the present invention contains only the amine additive among the amine additive and the acid additive, the content of the amine additive contained in the thermosetting conductive resin composition of the present invention is preferably 0.3 parts by mass or more and 20.0 parts by mass or less, more preferably 0.6 parts by mass or more and 10.0 parts by mass or less, and particularly preferably 1.8 parts by mass or more and 6.0 parts by mass or less, relative to 100 parts by mass of the thermosetting silicone resin having a hydroxyl group. When the content of the amine additive is within the above range, the effects of the present invention can be more suitably obtained.

[0054] When the thermosetting conductive resin composition of the present invention contains only the amine additive among the amine additive and the acid additive, the content of the amine additive contained in the thermosetting conductive resin composition of the present invention is preferably 0.05 parts by mass or more and 3.2 parts by mass or less, more preferably 0.1 parts by mass or more and 1.6 parts by mass or less, and particularly preferably 0.3 parts by mass or more and 1.4 parts by mass or less, relative to 100 parts by mass of the conductive powder containing a base metal. When the content of the amine additive is within the above range, the effects of the present invention can be more suitably obtained.

[0055] When the thermosetting conductive resin composition of the present invention contains only an acid-based additive among the amine-based additive and the acid-based additive, the content of the acid-based additive contained in the thermosetting conductive resin composition of the present invention is preferably 0.3 parts by mass or more and 20.0 parts by mass or less, more preferably 0.6 parts by mass or more and 10.0 parts by mass or less, and particularly preferably 1.8 parts by mass or more and 6.0 parts by mass or less, relative to 100 parts by mass of the thermosetting silicone resin having a hydroxyl group. When the content of the acid-based additive is within the above range, the effects of the present invention can be more suitably obtained.

[0056] When the thermosetting conductive resin composition of the present invention contains only the acid-based additive among the amine-based additive and the acid-based additive, the content of the acid-based additive contained in the thermosetting conductive resin composition of the present invention is preferably 0.05 parts by mass or more and 3.2 parts by mass or less, more preferably 0.1 parts by mass or more and 1.6 parts by mass or less, and particularly preferably 0.3 parts by mass or more and 1.4 parts by mass or less, relative to 100 parts by mass of the conductive powder containing a base metal. When the content of the acid-based additive is within the above range, the effects of the present invention can be more suitably obtained.

[0057] When the thermosetting conductive resin composition of the present invention contains both an amine-based additive and an acid-based additive, the total content of the amine-based additive and the acid-based additive contained in the thermosetting conductive resin composition of the present invention is preferably 0.3 parts by mass or more and 20.0 parts by mass or less, more preferably 0.6 parts by mass or more and 10.0 parts by mass or less, and particularly preferably 1.8 parts by mass or more and 6.0 parts by mass or less, relative to 100 parts by mass of the thermosetting silicone resin having a hydroxyl group. When the total content of the amine-based additive and the acid-based additive is within the above range, the effects of the present invention can be more suitably obtained.

[0058] When the thermosetting conductive resin composition of the present invention contains both an amine-based additive and an acid-based additive, the total content of the amine-based additive and the acid-based additive contained in the thermosetting conductive resin composition of the present invention is preferably 0.05 parts by mass or more and 3.2 parts by mass or less, more preferably 0.1 parts by mass or more and 1.6 parts by mass or less, and particularly preferably 0.3 parts by mass or more and 1.4 parts by mass or less, relative to 100 parts by mass of the conductive powder containing a base metal. When the total content of the amine-based additive and the acid-based additive is within the above range, the effects of the present invention can be more suitably obtained.

[0059] When the thermosetting conductive resin composition of the present invention contains both an amine-based additive and an acid-based additive, the content of the amine-based additive contained in the thermosetting conductive resin composition of the present invention is preferably 0.3 parts by mass or more and 20.0 parts by mass or less, more preferably 0.6 parts by mass or more and 10.0 parts by mass or less, and particularly preferably 1.8 parts by mass or more and 6.0 parts by mass or less, relative to 100 parts by mass of the thermosetting silicone resin having a hydroxyl group. Also, the content of the acid-based additive contained in the thermosetting conductive resin composition of the present invention is preferably 0.05 parts by mass or more and 3.2 parts by mass or less, more preferably 0.1 parts by mass or more and 1.6 parts by mass or less, and particularly preferably 0.3 parts by mass or more and 1.4 parts by mass or less, relative to 100 parts by mass of the conductive powder containing a base metal.

[0060] The thermosetting conductive resin composition of the present invention may further contain an organic solvent. The organic solvent contained is not particularly limited, and examples thereof include terpineol, dihydroterpineol, dihydroterpineol acetate, secondary butyl alcohol, butyl carbitol, butyl carbitol acetate, and benzyl alcohol. From the viewpoint of adhesion strength, acetate-based solvents are preferred, and butyl carbitol acetate is particularly preferred.

[0061] In addition to the above components, the thermosetting conductive resin composition of the present invention may contain additives such as antifoaming agents, plasticizers, dispersants, and rheology modifiers, as necessary. Examples of plasticizers include dimethyl phthalate, diethyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, di-n-octyl phthalate, butyl benzyl phthalate, dioctyl adipate, diisononyl adipate, dibutyl sebacate, diethyl sebacate, dioctyl sebacate, tricresyl phosphate, chlorinated paraffin, and cyclohexane 1,2-dicarboxylic acid diisononyl ester (DINCH). Examples of rheology modifiers include silica powder.

[0062] The thermosetting conductive resin composition of the present invention is suitably used for forming external electrodes of multilayer electronic components and cathodes of solid electrolytic capacitors.

[0063] The moisture permeability of the thermosetting conductive resin composition of the present invention is preferably 80.0 mg or less, more preferably 40.0 mg or less, even more preferably 20.0 mg or less, and particularly preferably 10.0 mg or less. When the moisture permeability is within the above range, when a conductive resin layer is formed using the conductive resin composition of the present invention, an electronic component having excellent moisture resistance can be obtained. The method for measuring the moisture permeability of the conductive resin composition of the present invention is not particularly limited, and can be measured, for example, by the moisture permeability measurement test described below. <Moisture Permeability Measurement Test> A conductive resin composition was cast onto a PET film to a thickness of 250 μm and cured at 200° C. for 60 minutes. The resulting cured film was cut into a circle with a diameter of 7.5 mm and fixed with an adhesive to a 5 ml glass bottle containing 2 g of silica gel so as to cover the bottle. The glass bottle was then placed in a 750 ml container containing 100 ml of purified water so that the cured film would not come into contact with the purified water, and the glass bottle was placed in a dryer set at 65° C. in a sealed state and left to stand for 15 hours. The moisture permeability was then calculated using the following formula (1): Moisture permeability (weight increase)=weight of glass bottle after being placed in dryer−weight of glass bottle before being placed in dryer (1).

[0064] The specific resistance of the conductive resin layer obtained by using the thermosetting conductive resin composition of the present invention is preferably 1.0×10 ５ μΩ cm or less, more preferably 5.0 × 10 ４ μΩ cm or less, more preferably 1.0 × 10 ４ μΩ cm or less, more preferably 5.0 × 10 ３ μΩ cm or less, more preferably 1.0 × 10 ３ The resistivity is μΩ·cm or less. The method for measuring the resistivity of the conductive resin composition of the present invention is not particularly limited, and can be measured, for example, by the following resistivity measurement test. <Resistivity Measurement Test> The conductive resin composition is cast onto a glass slide substrate to a width of 1 cm, length of 5 cm, and thickness of 50 μm, and cured at 200° C. for 60 minutes to obtain a cured film. The resistance of the surface of the cured film is then measured by the four-terminal method using a digital multimeter (e.g., KEITHLEY 2002, manufactured by Keithley Instruments), and the resistivity is calculated from the obtained value and the sample thickness.

[0065] The resistivity reduction rate of the thermosetting conductive resin composition of the present invention is preferably 15% or more, more preferably 30% or more, more preferably 50% or more, more preferably 70% or more, more preferably 80% or more, even more preferably 90% or more, and particularly preferably 95% or more. When the resistivity reduction rate is within the above range, when a conductive resin layer is formed using the thermosetting conductive resin composition of the present invention, an electronic component with excellent conductivity can be obtained. The method for calculating the resistivity reduction rate of the thermosetting conductive resin composition of the present invention is not particularly limited, and can be calculated, for example, by the resistivity reduction rate calculation method described below. <Method for Calculating Resistivity Reduction Rate> When a thermosetting conductive resin composition of the present invention containing the additive of the present invention (at least one of an amine-based additive and an acid-based additive) is defined as composition (X), and a thermosetting conductive resin composition having the same composition as composition (X) except that it does not contain the additive of the present invention (at least one of an amine-based additive and an acid-based additive) is defined as composition (Y), the resistivities of compositions (X) and (Y) are measured by the resistivity measurement test described above, and the obtained resistivities are defined as (A) and (B), respectively. Then, the resistivity reduction rate is calculated by the following formula (2):

[0066] The method for measuring the viscosity of the thermosetting conductive resin composition of the present invention is not particularly limited. For example, the viscosity can be measured using a rotational viscometer (manufactured by Brookfield, model number: HADV-II+Pro or HBDV-II+) at 25°C and a shear rate of 4 (1 / s).

[0067] The viscosity increase rate of the thermosetting conductive resin composition of the present invention is preferably 10.0 times or less, more preferably 8.0 times or less, more preferably 6.0 times or less, more preferably 4.0 times or less, even more preferably 2.0 times or less, and particularly preferably 1.5 times or less. A viscosity increase rate within the above range results in a thermosetting conductive resin composition with excellent viscosity stability. When the viscosity stability is low, the viscosity increases over time. An increase in viscosity can result in poor print shape. For example, when the thermosetting conductive resin composition of the present invention is printed on an electrode-forming substrate for electronic components, such as a laminate for a multilayer electronic component or a cathode-forming substrate for a solid electrolytic capacitor, to form an external electrode or a cathode, the print shape may be poor. Poor print shape can result in, for example, thin corners of the external electrode of a multilayer electronic component or the cathode of a solid electrolytic capacitor, which can result in the desired moisture resistance being lost when the electronic component is formed. Because the thermosetting conductive resin composition of the present invention has excellent viscosity stability, electronic components with high moisture resistance can be reliably obtained when the conductive resin composition of the present invention is used to form electronic components. The method for calculating the viscosity increase rate of the thermosetting conductive resin composition of the present invention is not particularly limited, and can be, for example, calculated by the following viscosity increase rate calculation method. <Viscosity Increase Rate Calculation Method> The viscosity of the thermosetting conductive resin composition of the present invention one day after production and one week after production are measured by the above-mentioned viscosity measurement method, and then the viscosity increase rate is calculated by the following formula (3): Viscosity increase rate [times] = viscosity one week after production / viscosity one day after production (3)

[0068] (Viscosity Increase Inhibition Rate) The viscosity increase inhibition rate of the thermosetting conductive resin composition of the present invention is preferably 10% or more, more preferably 20% or more, more preferably 30% or more, more preferably 40% or more, more preferably 50% or more, more preferably 60% or more, more preferably 70% or more, even more preferably 80% or more, and particularly preferably 90% or more. When the viscosity increase inhibition rate is within the above range, a thermosetting conductive resin composition with excellent viscosity stability can be obtained. Excellent viscosity stability makes it easier to stably obtain electronic components with high moisture resistance, for the same reasons as described above. The method for calculating the viscosity increase inhibition rate of the thermosetting conductive resin composition of the present invention is not particularly limited, and can be calculated, for example, by the viscosity increase inhibition rate calculation method described below. <Method for Calculating Viscosity Increase Suppression Rate> When the thermosetting conductive resin composition of the present invention containing the additive according to the present invention (at least one of an amine-based additive and an acid-based additive) is defined as composition (X), and a thermosetting conductive resin composition having the same composition as composition (X) except that it does not contain the additive (at least one of an amine-based additive and an acid-based additive) is defined as composition (Y), the viscosity increase rates of composition (X) and composition (Y) are measured by the above-mentioned viscosity increase rate measurement test, and the obtained viscosity increase rates are defined as (C) and (D), respectively. Then, the viscosity increase suppression rate is calculated by the following formula (4): Viscosity increase suppression rate [%]=(1−((C) / (D)))×100 (4)

[0069] The adhesive strength of the conductive resin layer obtained using the thermosetting conductive resin composition of the present invention is preferably 3.0 kg or more, more preferably 4.0 kg or more, even more preferably 5.0 kg or more, and particularly preferably 6.0 kg or more. The adhesive strength of the conductive resin layer obtained using the thermosetting conductive resin composition of the present invention is not particularly limited, but can be, for example, 20.0 kg or less. When a conductive resin layer having an adhesive strength within the above range is formed between the metal layer and plating layer of the external electrode of a multilayer electronic component, cracks and interfacial peeling are less likely to occur at the connection between the substrate and the electronic component, and cracks are less likely to occur in the electronic component itself, thereby improving the impact resistance of the electronic component. Therefore, by forming the conductive resin composition of the present invention between the metal layer and plating layer of the external electrode of a multilayer electronic component, the impact resistance of the electronic component can be improved. Furthermore, excellent adhesive strength makes the conductive resin layer less likely to peel from the electrode-forming body for electronic components, making it easier to maintain the moisture resistance of the electronic component. The method for measuring adhesive strength is not particularly limited, but it can be measured, for example, by the adhesive strength measurement test described below. <Adhesion Strength Measurement Test> The conductive resin composition is cast onto a slide glass substrate to a thickness of 50 μm, and an alumina chip measuring 1.5 mm in length, 3.0 mm in width, and 1.0 mm in height is placed on it. The composition is cured at 200°C for 60 minutes, and a force is applied in the horizontal direction at a speed of 0.3 mm / s using a bond tester (manufactured by Seishin Shoji Co., Ltd., model number: SS-30WD) to measure the value when the alumina chip peels off.

[0070] The cured film density of the thermosetting conductive resin composition of the present invention is preferably 2.0 g / cm ３ More preferably, 2.5 g / cm ３ More preferably, 3.0 g / cm ３ More preferably, it is 3.5 g / cm ３ More preferably, it is 4.0 g / cm ３That is all. When the cured film density is within the above range, when a conductive resin layer is formed using the conductive resin composition of the present invention, an electronic component having excellent conductivity and moisture resistance can be obtained. The method for measuring the density of the cured film of the conductive resin composition of the present invention is not particularly limited. For example, the conductive resin composition is cast on a PET film to a thickness of 250 μm to form a coating film, and the coating film is cured under conditions of air atmosphere, 200° C., and 60 minutes to form a cured film. The obtained cured film is cut into a circle, and the weight and volume of the cut cured film are measured, and the volume (cm ３ The cured film density (g / cm) was calculated as the ratio of the weight (g) to the ３ ) can be calculated.

[0071] The thermosetting conductive resin composition of the present invention is suitable as a thermosetting conductive resin composition for forming electrodes on an electrode-formed body (hereinafter also referred to as an electrode-formed body for electronic components) in the manufacture of electronic components. The thermosetting conductive resin composition of the present invention is particularly suitable as a thermosetting conductive resin composition for forming external electrodes on a laminate for multilayer electronic components and for forming a cathode on a cathode-formed body for solid electrolytic capacitors.

[0072] In one use example, the thermosetting conductive resin composition of the present invention can be used in a method for manufacturing electronic components, which includes a preparation step of preparing an electrode-forming body for electronic components and an electrode-forming step of forming electrodes on the outer surface of the electrode-forming body for electronic components. In the electrode-forming step, the thermosetting conductive resin composition of the present invention is used to form a conductive resin layer on the electrode-forming body for electronic components, thereby forming an electrode.

[0073] The preparation step is a step of preparing an electrode-formed body for electronic components. The electrode-formed body for electronic components refers to the object on which electrodes are formed in the manufacturing process of electronic components. Examples of electrode-formed bodies for electronic components include laminates for multilayer electronic components consisting of multiple ceramic layers and multiple internal electrode layers, cathode-formed bodies for solid electrolytic capacitors consisting of an anode and a dielectric layer formed on the surface of the anode, and electrode-formed bodies for chip resistors having end electrodes.

[0074] A laminate for a multilayer electronic component comprises a plurality of ceramic layers and a plurality of internal electrode layers. In the laminate for a multilayer electronic component, adjacent ceramic layers are connected to each other by the internal electrode layer interposed therebetween. Examples of the laminate for a multilayer electronic component include laminates for multilayer ceramic capacitors, laminates for multilayer ceramic inductors, and laminates for piezoelectric actuators.

[0075] Examples of materials for forming the ceramic layers constituting the laminate for multilayer electronic components include barium titanate, strontium titanate, calcium titanate, barium zirconate, strontium zirconate, calcium zirconate, and strontium calcium zirconate.

[0076] Examples of materials for forming the internal electrode layers constituting the laminate for multilayer electronic components include nickel, palladium, silver, copper, and gold, or alloys containing one or more of these (e.g., an alloy of silver and palladium).

[0077] The cathode-forming body for a solid electrolytic capacitor comprises an anode and a dielectric layer formed on the surface of the anode. Examples of the combination of materials for the anode and the dielectric layer include tantalum and tantalum pentoxide, aluminum and aluminum oxide, and niobium and niobium pentoxide.

[0078] The electrode formation step is a step of forming an electrode on the outer surface of an electronic component electrode-forming body. In the present invention, forming a conductive resin layer on an electronic component electrode-forming body includes both forming a conductive resin layer directly on the surface of the electronic component electrode-forming body and forming a conductive resin layer on the surface of the electronic component electrode-forming body after forming another layer or film (e.g., a metal layer, a conductor layer) on the electronic component electrode-forming body first. Therefore, in the electronic component obtained by the electronic component manufacturing method of the present invention, there are two cases: a conductive resin layer is formed directly on the surface of the electronic component electrode-forming body, and a conductive resin layer is formed with another layer or film (e.g., a metal layer, a conductor layer) interposed between the electronic component electrode-forming body and the conductive resin layer.

[0079] In the electrode formation step, the position, method, thickness, number of electrodes, type of metal constituting the electrodes, shape of the conductive powder used to form the electrodes, etc. are appropriately selected depending on the electronic component to be manufactured.

[0080] In the electrode formation step, a conductive resin layer is formed on an electrode-forming body for electronic components using the thermosetting conductive resin composition of the present invention.

[0081] In the electrode formation step, the thermosetting conductive resin composition of the present invention is applied to an electrode-forming body for electronic components to form a layer of the thermosetting conductive resin composition of the present invention at a predetermined position on the electrode-forming body for electronic components, and then the thermosetting conductive resin composition of the present invention is cured to form a conductive resin layer. The curing is carried out by heating.

[0082] In the electrode formation step, a conductive resin layer can be formed directly on the surface of an electronic component electrode-forming body by applying the thermosetting conductive resin composition of the present invention directly to the surface of the electronic component electrode-forming body. Furthermore, in the electrode formation step, an appropriate step can be included depending on the type of electronic component before forming the conductive resin layer on the electronic component electrode-forming body. For example, in the case of a laminated electronic component, the electrode formation step involves forming a metal layer at a predetermined position on the electronic component electrode-forming body, applying the thermosetting conductive resin composition of the present invention to the surface of the metal layer, or the like, to form a layer of the thermosetting conductive resin composition of the present invention at a predetermined position on the electronic component electrode-forming body, and then curing the thermosetting conductive resin composition of the present invention to form a conductive resin layer on the surface of the metal layer. For example, in the case of a solid electrolytic capacitor, the electrode formation step involves forming a conductive layer consisting of a carbon layer at a predetermined position on a cathode-forming body for a solid electrolytic capacitor, applying the thermosetting conductive resin composition of the present invention to the surface of the conductive layer, thereby forming a thermosetting conductive resin composition layer at a predetermined position on the electrode-forming body for an electronic component, and then curing the thermosetting conductive resin composition to form a conductive resin layer on the surface of the conductive layer. Furthermore, in the electrode formation step, after forming the conductive resin layer on the electrode-forming body for an electronic component, appropriate steps may be included depending on the type of electronic component. For example, in the case of a laminated electronic component, the electrode formation step involves forming a conductive resin layer at a predetermined position on the electrode-forming body for an electronic component, and then forming a plating layer on the surface of the conductive resin layer.

[0083] In the electrode formation step, an electrode can be formed by forming a conductive resin layer on the electrode-forming body for electronic components. That is, in this embodiment, the electrode is composed only of the conductive resin layer.

[0084] In the electrode formation process, when a conductive resin layer is formed on an electronic component electrode-forming body using the thermosetting conductive resin composition of the present invention, the thermosetting conductive resin composition of the present invention is applied to the electronic component electrode-forming body by a dipping method, and a layer of the thermosetting conductive resin composition of the present invention can be formed at a predetermined position on the electronic component electrode-forming body.

[0085] The first form of the electrode formation step (hereinafter also referred to as electrode formation step (1)) is an electrode formation step in the case where the electronic component electrode formation body is a laminate for a multilayer electronic component comprising a ceramic layer and an internal electrode layer. The electrode formation step (1) includes at least a conductive resin layer formation step (1A) in which a conductive resin layer is formed on the outer surface of the laminate for a multilayer electronic component using the thermosetting conductive resin composition of the present invention. The electrode formation step (1) is not particularly limited as long as it includes a conductive resin layer formation step (1A) in which a conductive resin layer is formed on the outer surface of the laminate for a multilayer electronic component using the conductive resin composition of the present invention. For example, an electrode formation step (1) including at least a metal layer formation step, a conductive resin layer formation step (1A), and a plating layer formation step can be mentioned.

[0086] The metal layer forming step is a step of forming a metal layer electrically connected to the internal electrode layer on the outer surface of the laminate for multilayer electronic components. Examples of metals that form the metal layer include at least one of Cu, Ag, Pd, Ni, Sn, Al, Au, and Pt, or alloys containing at least one of these. The method for forming the metal layer is not particularly limited, and examples include dipping, plating, roll coating, screen printing, and sputtering. The thickness, shape, position, number, etc. of the metal layer are selected appropriately.

[0087] The conductive resin layer forming step (1A) is a step of forming a conductive resin layer on the surface of the metal layer formed in the metal layer forming step, using the thermosetting conductive resin composition of the present invention.

[0088] In the conductive resin layer forming step (1A), the thermosetting conductive resin composition of the present invention is applied to the surface of the metal layer formed in the metal layer forming step, thereby forming a layer of the thermosetting conductive resin composition of the present invention on the surface of the metal layer, and then the thermosetting conductive resin composition of the present invention is cured to form a conductive resin layer. The method for forming the conductive resin layer is not particularly limited, and examples include a dipping method, a screen printing method, and a roll coating method. Of these, the dipping method is preferred. The thickness, shape, position, number, etc. of the thermosetting conductive resin composition layer of the present invention are selected as appropriate.

[0089] The plating layer forming step is a step of forming a plating layer on the surface of the conductive resin layer. Examples of metals that form the plating layer include at least one of Ni, Cu, Sn, Ag, and Au, or alloys containing at least one of these. The method for forming the plating layer is not particularly limited, and examples include electrolytic plating and electroless plating. The thickness, shape, position, number, and other aspects of the plating layer are appropriately selected.

[0090] The second form of the electrode formation step (hereinafter also referred to as electrode formation step (2)) is an electrode formation step when the body to be formed with an electrode for an electronic component is a body to be formed with a cathode for a solid electrolytic capacitor. The electrode formation step (2) includes at least a conductive resin layer formation step (2A) in which a conductive resin layer is formed on the outer surface of the body to be formed with a cathode for a solid electrolytic capacitor using the thermosetting conductive resin composition of the present invention. The electrode formation step (2) is not particularly limited as long as it includes a conductive resin layer formation step (2A) in which a conductive resin layer is formed on the outer surface of the body to be formed with a cathode for a solid electrolytic capacitor using the thermosetting conductive resin composition of the present invention. For example, the electrode formation step (2) may include at least a solid electrolyte layer formation step, a carbon layer formation step, and a conductive resin layer formation step (2A).

[0091] The solid electrolyte layer forming step is a step of forming a solid electrolyte layer on the outer surface of a cathode-forming body for a solid electrolytic capacitor. The method for forming the solid electrolyte layer is not particularly limited, and the solid electrolyte layer can be formed using a known solid electrolyte produced by a chemical method, such as a conductive polymer such as polypyrrole, polyaniline, polythiophene, or polyacetylene.

[0092] The carbon layer forming step is a step of forming a carbon layer on the solid electrolyte layer. The method for forming the carbon layer is not particularly limited, and examples thereof include a method in which a carbon paste containing a resin, a solvent, and carbon powder is applied to the solid electrolyte layer by a dipping method, followed by drying and / or curing. The carbon powder is not particularly limited, but graphite powder is preferred.

[0093] The conductive resin layer forming step (2A) is a step of forming a conductive resin layer on the carbon layer using the thermosetting conductive resin composition of the present invention. The method for forming the conductive resin layer is not particularly limited, and examples thereof include a method of applying the conductive resin composition of the present invention by a dipping method, a screen printing method, a roll coating method, or the like, and then curing the thermosetting conductive resin composition.

[0094] Another example of the electrode formation step is an electrode formation step (3) in which the electronic component electrode formation body is a chip resistor electrode formation body having end surface electrodes. The electrode formation step (3) includes at least a step of forming a conductive resin layer on the end surface electrodes. The method for forming the conductive resin layer is not particularly limited, and examples include a method in which the thermosetting conductive resin composition of the present invention is applied by a dipping method, a screen printing method, a roll coating method, or the like, and then the thermosetting conductive resin composition of the present invention is cured. An electrode formation body for a chip resistor having end surface electrodes includes, for example, an insulating substrate, a pair of upper surface electrodes formed on the insulating substrate, a resistor formed between the pair of upper surface electrodes, a protective layer formed to cover a portion of the pair of upper surface electrodes and the resistor, and end surface electrodes formed on the end surfaces of the insulating substrate.

[0095] Another example of the electrode formation step is an electrode formation step (4) in which the electronic component electrode-forming body is a substrate. The electrode formation step (4) includes at least a step of forming a conductive resin layer on the substrate. The method for forming the conductive resin layer is not particularly limited, and examples include a method in which the thermosetting conductive resin composition of the present invention is applied by screen printing, inkjet printing, or dispenser printing, and then the conductive composition of the present invention is cured. Examples of the substrate include an alumina substrate, a glass epoxy substrate, a paper phenol substrate, and a paper epoxy substrate.

[0096] Another example of the electrode formation step is the electrode formation step (5) in which the electrode-forming body for electronic components is a film. The electrode formation step (5) includes at least a step of forming a conductive resin layer on the film. The method for forming the conductive resin layer is not particularly limited, and examples include a method in which the thermosetting conductive resin composition of the present invention is applied by screen printing, inkjet printing, or dispenser printing, and then the conductive composition of the present invention is cured. Examples of the film include a polyimide film and a PET film.

[0097] The present invention will be described below based on specific experimental examples, but the present invention is not limited to these.

[0098] <Production of Spherical Silver-Coated Copper Powder> Spherical silver-coated copper powder (conductive powder 1) was produced by coating with silver in a ratio of 10 parts by mass to 90 parts by mass of spherical copper powder (Mitsui Metals, model number: MA-CO3K). The 50% value (D ５０ The specific surface area was measured by the BET method.

[0099] <Production of flaky silver-coated copper powder> Spherical silver-coated copper powder was produced by the method described above, and the obtained spherical silver-coated copper powder was pulverized in a ball mill using palmitic acid as a lubricant to produce flaky silver-coated copper powder (conductive powder 2). The number average particle diameter (D ５０ The specific surface area was measured by the BET method.

[0100] <Production of spherical silver powder> First, spherical silver powder (conductive powder 5) was prepared based on the spray pyrolysis method described in Japanese Patent Publication No. 63-31522. That is, for the spherical silver powder, an aqueous solution in which a silver salt was dissolved was spray-pyrolyzed, and the collected silver powder was classified to obtain D ５０ The value of D was adjusted. Note that the 50% value of the cumulative volume fraction (D ５０The specific surface area was measured by the BET method.

[0101] <Production of flaky silver powder> Spherical silver powder was produced by the above-mentioned method, and the obtained spherical silver powder was pulverized in a ball mill using stearic acid as a lubricant to produce flaky silver powder (conductive powder 3). The number average particle diameter (D ５０ The specific surface area was measured by the BET method.

[0102] <Preparation of Conductive Resin Compositions> Conductive powders and silicone resins were blended in the blending ratios shown in Tables 1 and 2 to prepare conductive resin compositions. The units of values ​​shown in Tables 1 and 2 are parts by mass. In the tables, "BCA" is an abbreviation for butyl carbitol acetate, and "BZA" is an abbreviation for benzyl alcohol. Conductive Powder 1: Spherical silver-coated copper powder, D ５０ : 4.0μm, specific surface area: 0.5m ２ / g Conductive powder 2 Flake-shaped silver-coated copper powder, aspect ratio: 20, D ５０ : 8.0μm, specific surface area: 1.5m ２ / g Conductive powder 3 Flake silver powder, aspect ratio: 30, D ５０ : 6.0μm, specific surface area: 1.0m ２ / g Conductive powder 4 Spherical nickel powder, D ５０ :0.8μm, specific surface area: 1.2m ２ / g ・Conductive powder 5 Spherical silver powder, D ５０ : 2.3μm, specific surface area: 0.5m ２ / g Silicone Resin 1 A thermosetting silicone resin having a hydroxyl group, dehydration condensation type, manufactured by Shin-Etsu Chemical Co., Ltd., Model No. ES-1001N. As the silicone resin 1, two different lots, Lot A and Lot B, were used. Silicone resin 2: A thermosetting silicone resin without a hydroxyl group, addition curing type, manufactured by Shin-Etsu Chemical Co., Ltd., model number: X-40-2756 (one-component type containing a curing catalyst), other functional groups: alkenyl group, methyl group, phenyl group Amine additive 1: Dibutylamine Secondary amine, molecular weight: 129.2, number of carbon atoms: 8, boiling point: 159°C, pKa: 11.3 Amine additive 2: N-lauryldiethanolamine Tertiary amine, molecular weight: 273.5, number of carbon atoms: 16, pKa: 14 Amine additive 3: Triethanolamine Tertiary amine, molecular weight: 149.2, number of carbon atoms: 6, boiling point: 335.4, pKa: 7.8 Amine additive 4: Diisopropylamine Secondary amine, molecular weight: 101.2, number of carbon atoms: 6, boiling point: 84°C, pKa: 11.1 Amine additive 5: Dihexylamine Amine additive 6: dimethyloctylamine, secondary amine, molecular weight: 185.4, number of carbon atoms: 12, boiling point: 194°C Amine additive 6: dimethyloctylamine, tertiary amine, molecular weight: 157.3, number of carbon atoms: 10, boiling point: 195°C Acid additive 1: octadecylbutanedioic acid dicarboxylic acid, molecular weight: 369, number of carbon atoms: 22, Td90: 350°C Acid additive 2: octenylsuccinic acid dicarboxylic acid, molecular weight: 228.3, number of carbon atoms: 12 Acid / base mixed additive 1 HIPLAAD ED401, manufactured by Kusumoto Chemicals Co., Ltd. Note that the amount of resin in the tables below refers to the amount of resin itself excluding the solvent.

[0103] Comparative Example 1 Silicone resin 1, conductive powder 1, conductive powder 2, and butyl carbitol acetate were mixed in the ratios shown in Table 1, and then kneaded using a three-roll mill (manufactured by Inoue Seisakusho) to obtain a paste composition.

[0104] (Example 1) Silicone resin 1, conductive powder 1, conductive powder 2, amine additive 1, and butyl carbitol acetate were mixed in the ratios shown in Table 1, and then kneaded using a three-roll mill (manufactured by Inoue Seisakusho) to obtain a paste composition.

[0105] (Example 2) Silicone resin 1, conductive powder 1, conductive powder 2, amine additive 2, and butyl carbitol acetate were mixed in the ratios shown in Table 1, and then kneaded using a three-roll mill (manufactured by Inoue Seisakusho) to obtain a paste-like composition.

[0106] (Examples 3 to 22, Comparative Examples 2 to 6) The components shown in Table 1 or Table 2 were mixed in the ratios shown in Table 1 or Table 2, and then kneaded using a three-roll mill (manufactured by Inoue Seisakusho) to obtain paste-like compositions.

[0107] The paste-like compositions obtained in Examples 1 to 19, Examples 21 and 22, Comparative Examples 1 to 3, and Comparative Examples 5 and 6 were diluted with butyl carbitol acetate, and the paste-like compositions obtained in Example 20 and Comparative Example 4 were diluted with benzyl alcohol to adjust the viscosity to 30 Pa s at 25°C and a shear rate of 4 (1 / s), and then the following evaluations were carried out. The results are shown in Tables 3 and 4.

[0108] <Performance Evaluation> (Moisture Permeability) The conductive resin composition was cast onto a PET film to a thickness of 250 μm and cured at 200°C for 60 minutes to obtain a cured film. The obtained cured film was cut into a circle with a diameter of 7.5 mm and fixed with an adhesive to a 5 ml glass bottle containing 2 g of silica gel. The glass bottle was then placed in a 750 ml container containing 100 ml of purified water so that the cured film would not come into contact with the purified water, and the sealed container was placed in a dryer set at 65°C and left to stand for 15 hours. The weight of the glass bottle was measured before and after placing it in the dryer, and the weight increase was taken as the moisture permeability. A moisture permeability of more than 80.0 mg was rated as "fail, poor moisture resistance," and a moisture permeability of 80.0 mg or less was rated as "pass, high moisture resistance."

[0109] (Specific Resistivity) The conductive resin composition was cast onto a slide glass substrate to a width of 1 cm, length of 5 cm, and thickness of 50 μm, and cured at 200° C. for 60 minutes to obtain a cured film. The resistance of the cured film surface was measured by the four-terminal method using a digital multimeter (KEITHLEY 2002, manufactured by Keithley Instruments), and the specific resistance was calculated from the obtained value and the sample thickness.

[0110] (Resistivity Reduction Rate) The resistivity of the viscosity-adjusted paste composition (X) containing an additive (at least one of an amine-based additive and an acid-based additive), calculated by the method described above, and the resistivity of the viscosity-adjusted paste composition (Y) having the same composition as the paste composition (X) except that it does not contain an additive (at least one of an amine-based additive and an acid-based additive), were designated as (A) and (B), respectively, and the resistivity reduction rate was calculated by the following formula: Resistivity reduction rate [%] = (1 - ((A) / (B))) × 100

[0111] (Viscosity Increase Rate) The viscosity of the viscosity-adjusted paste composition one day after preparation and one week or four weeks after preparation was measured using a rotational viscometer (Brookfield, model number: HADV-II+Pro or HBDV-II+) at 25°C and a shear rate of 4 (1 / s), and the ratio of the viscosity one day after preparation to the viscosity one week or four weeks after preparation was calculated as the viscosity increase rate. The viscosity-adjusted paste composition was stored in a sealed container at 25°C. Note that for Examples 21 and 22 and Comparative Examples 5 and 6, the viscosity increase rate was calculated based on the viscosity four weeks after preparation, and for the other Examples and Comparative Examples, the viscosity increase rate was calculated based on the viscosity one week after preparation.

[0112] (Viscosity Increase Inhibition Rate) The viscosity increase rate of the viscosity-adjusted paste composition (X) containing an additive (at least one of an amine-based additive and an acid-based additive) and the viscosity increase rate of the viscosity-adjusted paste composition (Y) having the same composition as the paste composition (X) except that it does not contain an additive (at least one of an amine-based additive and an acid-based additive), calculated by the above-mentioned method, were designated as (C) and (D), respectively, and the resistivity reduction rate was calculated by the following formula: Viscosity increase inhibition rate [%] = (1 - ((C) / (D))) × 100

[0113] (Adhesion Strength) The conductive resin composition was cast onto a glass slide substrate to a thickness of 50 μm, and an aluminum cylinder having a diameter of 3 mm was placed on top, followed by curing at 200° C. for 60 minutes. Using a bond tester (manufactured by Seishin Shoji Co., Ltd., model number: SS-30WD), the film was pulled in the vertical direction at a rate of 0.5 mm / s, and the value at break was measured.

[0114] (Cured Film Density) The conductive resin composition was cast onto a PET film to a thickness of 250 μm to form a coating film, and the coating film was cured in an air atmosphere at 150° C. for 10 minutes to form a cured film. The obtained cured film was cut into a circle, and the weight and volume of the cut cured film were measured to determine the volume (cm ３ The cured film density (g / cm) was calculated as the ratio of the weight (g) to the ３ ) was calculated.

[0115]

[0116]

[0117]

[0118]

[0119] The results in Tables 3 and 4 show that Examples 1 and 2 have extremely low resistivity compared to Comparative Example 1 and also have high viscosity stability compared to Comparative Example 1. This demonstrates that electronic components with superior conductivity can be manufactured compared to when the conductive resin composition of Comparative Example 1 is used. Furthermore, because the viscosity stability is higher than that of Comparative Example 1, the coating shape is good even when electronic components are manufactured using a conductive resin composition that has been produced for a certain period of time. As a result, it was demonstrated that electronic components with high moisture resistance can be manufactured compared to when the conductive resin composition of Comparative Example 1 is used. Furthermore, in Examples 3 to 22, as in Examples 1 and 2, the effects of reducing resistivity and suppressing viscosity increase were confirmed.

[0120] (Reference Example 1) A viscosity-adjusted paste-like composition was obtained and evaluated as described above in the same manner as in Comparative Example 1, except that 40 parts by mass of Conductive Powder 5 and 60 parts by mass of Conductive Powder 3 were used as the conductive powders. The viscosity increase rate was 1.1 times. In other words, when silver powder was used as the conductive powder, no problems with viscosity stability occurred.

[0121] Reference Example 2 A paste-like composition was obtained using the same method as in Comparative Example 1, except that silicone resin 2 was used instead of silicone resin 1. The obtained paste-like composition was diluted with butyl carbitol acetate and adjusted to a viscosity of 30 Pa s at 25°C and a shear rate of 4 (1 / s), and then the above evaluation was performed, resulting in a viscosity increase rate of 0.9 times. In other words, when an addition-curing silicone resin was used as the silicone resin, no problems with viscosity stability occurred.

[0122] (Example 23) Each metal paste was prepared and evaluated in the same manner as in Comparative Example 1 and Example 1, except that 100 parts by mass each of spherical tin powder, spherical zinc powder, and spherical aluminum powder was used as the conductive powder. The amine-based additive was confirmed to have a lower resistivity and suppress the increase in viscosity, and it was also confirmed that the paste exhibited high moisture resistance. In particular, when spherical tin powder was used as the conductive powder, the resistivity exceeded the upper limit of measurement when neither the amine-based additive nor the acid-based additive according to the present invention was included. However, by including 5.0 parts by mass of the amine-based additive 1 as the additive according to the present invention relative to 100 parts by mass of the silicone resin, the conductivity was dramatically improved, and the resistivity was 2.9 × 10 ３ The resistivity was μΩ·cm, and the rate of decrease in resistivity was more than 99%.

[0123] (Example 24) A paste was prepared and evaluated in the same manner as in Comparative Example 1 and Example 1 above, using a thermosetting silicone resin having a hydroxyl group instead of Silicone Resin 1. The amine-based additive was confirmed to have the effect of reducing resistivity and suppressing viscosity increase, and also to exhibit high moisture resistance.

Claims

1. a conductive powder containing a base metal; a thermosetting silicone resin that has a hydroxyl group and cures by heating without the use of a curing agent or catalyst; at least one of an amine-based additive and an acid-based additive; A thermosetting conductive resin composition comprising:

2. 2. The thermosetting conductive resin composition according to claim 1, wherein the molecular weight of the amine-based additive or the acid-based additive is 30 or more and 2,000 or less.

3. 2. The thermosetting conductive resin composition according to claim 1, wherein the boiling point Tb or the 90% mass loss temperature Td90 of the amine-based additive or the acid-based additive at 1 atmosphere is 80°C or higher and 400°C or lower.

4. 2. The thermosetting conductive resin composition according to claim 1, wherein the amine-based additive comprises at least one of a secondary amine and a tertiary amine.

5. 2. The thermosetting conductive resin composition according to claim 1, wherein the acid additive comprises a dicarboxylic acid.

6. 2. The thermosetting conductive resin composition according to claim 1, wherein the content of the amine-based additive is 0.6 parts by mass or more and 10.0 parts by mass or less relative to 100 parts by mass of the thermosetting silicone resin that has a hydroxyl group and that cures by heating without the use of a curing agent or a catalyst, and / or the content of the acid-based additive is 0.1 parts by mass or more and 1.6 parts by mass or less relative to 100 parts by mass of the conductive powder containing a base metal.

7. The thermosetting conductive resin composition according to claim 1, characterized in that the thermosetting silicone resin which has hydroxyl groups and which cures by heating without the use of a curing agent or catalyst is a dehydration condensation type thermosetting silicone resin which has hydroxyl groups and which cures by heating through a dehydration condensation reaction without the use of a curing agent or catalyst.

8. The thermosetting conductive resin composition according to claim 1, characterized in that it is used for forming external electrodes of laminated electronic components or for forming cathodes of solid electrolytic capacitors.

9. A thermosetting conductive resin composition as described in claim 1, further characterized in that it contains an organic solvent.

10. A thermosetting conductive resin composition as described in claim 1, further characterized in that it contains a resin binder other than a thermosetting silicone resin that has a hydroxyl group and hardens by heating without the use of a curing agent or catalyst.

11. The thermosetting conductive resin composition according to claim 1, characterized in that the base metal is Cu and the amine-based additive is contained.

12. A thermosetting conductive resin composition as described in claim 1, characterized in that it is a thermosetting conductive resin composition that hardens when heated at a heating temperature within the range of 150°C or higher and 300°C or lower.

13. a preparation step of preparing an electrode-forming body for electronic components; an electrode forming step of forming an electrode on the outer surface of the body for forming an electrode for electronic components; and In the electrode forming step, the thermosetting conductive resin composition according to any one of claims 1 to 12 is applied to an electrode-forming body for electronic components, and then the thermosetting conductive resin composition is cured to form a conductive resin layer on the electrode-forming body for electronic components. A method for manufacturing an electronic component, comprising:

14. The method for manufacturing an electronic component according to claim 13, characterized in that the thermosetting conductive resin composition is cured by heating at a temperature in the range of 150°C or higher and 300°C or lower.