WO2021095495A1

WO2021095495A1 - Conductive silicone composition, cured conductive silicone product, production method for cured conductive silicone product, and conductive silicone laminate

Info

Publication number: WO2021095495A1
Application number: PCT/JP2020/040036
Authority: WO
Inventors: 将太田中; 初彦服部
Original assignee: 信越化学工業株式会社
Priority date: 2019-11-12
Filing date: 2020-10-26
Publication date: 2021-05-20
Also published as: TW202128882A; JP2021075655A

Abstract

The present invention is a conductive silicone composition characterized by including: (A) an organopolysiloxane having in each molecule at least two groups having a hydrosilylation-reactive carbon-carbon unsaturated bond; (B) an organohydrogenpolysiloxane having in each molecule at least two SiH groups; (C) a bis(β-diketonato) platinum complex; and (D) conductive particles. Provided thereby is an addition-curable conductive silicone composition having excellent storability and deep curability without requiring the addition of a reaction control agent.

Description

Conductive silicone composition, conductive silicone cured product, method for producing conductive silicone cured product, and conductive silicone laminate

The present invention relates to a conductive silicone composition, a cured product thereof, a method for producing the cured product, and a laminate having the cured product.

Conventionally, a conductive composition called a conductive adhesive or a conductive paste in which conductive particles are dispersed in a resin has been widely used for applications such as mounting an element on a substrate and forming a circuit by printing. (Patent Document 1).

Epoxy resins, which have been widely used as binders for these conductive compositions, have excellent mechanical strength such as adhesive strength, but are inferior in flexibility and elasticity, and the base material itself forming a circuit such as a so-called wearable device is bent. , It was difficult to apply it to expansion and contraction applications.

For such problems, the use of silicone resin or the like as a binder having more flexibility is being studied (Patent Document 2). As a method for curing the silicone resin, addition curing using a hydrosilylation reaction between an unsaturated carbon group and a SiH group is mainly used. This reaction proceeds rapidly in the presence of a catalyst composed of an unsaturated carbon group, a SiH group, a platinum compound, a ruthenium compound, or the like, and is easily cured at room temperature. Therefore, it is common to use a so-called reaction control agent which has an effect of partially inhibiting or delaying a catalytic reaction in order to impart an appropriate pot life and storage stability.

In a conductive adhesive characterized by containing a high proportion of conductive particles, the catalyst may be inactivated due to the influence of the conductive particles or the surface treatment agent thereof, and the curability may decrease after long-term storage. A conductive adhesive to which a large amount of catalyst is added in order to ensure sufficient curability requires the addition of a large amount of reaction control agent and has many restrictions such as storage at a low temperature.

Further, the curable silicone containing a high proportion of silver powder and the like tends to have poor curability under air-deficient conditions, and when such a conductive composition is used as an adhesive, the temperature is about 80 to 150 ° C. There was a problem that the inside of the bonded portion did not harden when heated at a relatively low temperature. This tendency was remarkable when the reaction control agent was added, and it was difficult to achieve both storage stability and curability. Patent Document 3 uses a microencapsulated hydrosilylation catalyst that is stable under environmental conditions, but still requires the addition of a reaction control agent, and can be stored at room temperature and thermoset without using a reaction control agent. A conductive adhesive capable of achieving both properties has been desired.

Japanese Unexamined Patent Publication No. 2000-319622 Japanese Unexamined Patent Publication No. 2004-119254 Japanese Unexamined Patent Publication No. 2002-088337

A conductive adhesive containing a high proportion of conductive particles requires the addition of a large amount of catalyst, a large amount of reaction control agent, and storage at a low temperature in order to ensure sufficient curability. There was a problem with many restrictions such as. In addition, the curable silicone containing a high proportion of silver powder and the like tends to have poor curability under air-deficient conditions, and when such a conductive composition is used as an adhesive, the temperature is about 80 to 150 ° C. There was a problem that the inside of the bonded portion did not harden when heated at a relatively low temperature. This tendency is remarkable when the reaction control agent is added, and there is a problem that it is difficult to achieve both storage stability and curability.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an addition-curable conductive silicone composition which does not require the addition of a reaction control agent and has excellent deep curability and storage stability.

In order to achieve the above object, in the present invention,
(A) An organopolysiloxane having at least two groups having a hydrosilylation-reactive carbon-carbon unsaturated bond in one molecule.
(B) Organohydrogenpolysiloxane having at least two SiH groups in one molecule,
(C) Bis (β-diketonato) platinum complex,
(D) Conductive particles,
Provided is a conductive silicone composition comprising.

With such a material, it is possible to obtain an add-curable conductive silicone composition having high conductivity excellent in deep curability and storage stability without the need for addition of a reaction control agent.

At this time, it is preferable that the group having the hydrosilylation-reactive carbon-carbon unsaturated bond in the component (A) is an alkenyl group having 2 to 10 carbon atoms.

With such a material, it is possible to more reliably obtain an add-curable conductive silicone composition having excellent deep curability and storage stability.

At this time, the number of SiH groups in the component (B) is 0.5 to 10.0 with respect to one hydrosilylation-reactive carbon-carbon unsaturated bond in the component (A). It is preferable to have.

With such a product, a cured product with excellent mechanical properties can be obtained.

At this time, the content of the component (D) is preferably 50 to 99% by mass with respect to the total mass of the composition.

With such a material, a composition having further excellent curability and handleability can be obtained, and sufficient conductivity can be imparted to the cured product.

At this time, it is preferable that the component (D) is silver powder.

If it is such a thing, it is possible to give more conductivity to the cured product.

At this time, (E) an adhesive aid can be further contained.

If it is such a thing, the adhesiveness to the resin can be improved.

At this time, it is preferable that the component (E) is a compound having an α-silyl ester structure.

If it is such a thing, the adhesiveness to the resin can be further improved.

Further, the present invention provides a cured product of the above-mentioned conductive silicone composition having a volume resistivity of 1.0 × 10 ^-3 Ω · cm or less.

With such a product, a cured product having high conductivity as well as flexibility and elasticity can be obtained.

Further, the present invention provides the above-mentioned method for producing a conductive silicone cured product, which is a method for producing a conductive silicone cured product in which the conductive silicone composition is cured at a temperature of 80 to 150 ° C.

By doing so, curing progresses sufficiently, and it is possible to prevent the composition from becoming brittle.

Further, the present invention provides a laminate having the above-mentioned conductive silicone cured product.

With such a material, a laminated body having high conductivity can be obtained.

The conductive silicone composition of the present invention has high conductivity, excellent curability, and high storage stability. The conductive silicone composition of the present invention having such characteristics is useful as a conductive adhesive or a conductive paste for adhering electronic components or elements to a substrate, forming an electronic circuit, or the like.

Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto.

As described above, there has been a demand for the development of an add-curable conductive silicone composition which is highly conductive, does not require the addition of a reaction control agent, and has excellent deep curability and storage stability.

As a result of diligent studies on the above problems, the present inventors have applied a hydrosilylation catalyst having a specific structure in a conductive composition in which an addition-curable liquid silicone rubber is filled with a conductive filler. The present invention has been completed by finding that a conductive composition having excellent storage stability at room temperature can be obtained without adding a reaction control agent while maintaining deep curability such as inside the mating portion.

That is, the present invention
(A) An organopolysiloxane having at least two groups having a hydrosilylation-reactive carbon-carbon unsaturated bond in one molecule.
(B) Organohydrogenpolysiloxane having at least two SiH groups in one molecule,
(C) Bis (β-diketonato) platinum complex,
(D) Conductive particles,
It is a conductive silicone composition characterized by containing.

The conductive silicone composition of the present invention contains the following components (A) to (D).

[(A) component]
The component (A) in the conductive silicone composition of the present invention is an organopolysiloxane having at least two groups having a hydrosilylation-reactive carbon-carbon unsaturated bond in one molecule.

As the component (A), for example, an organopolysiloxane represented by the following average formula (1) can be used.

In formula (1), R ¹ is a group having a hydrosilylation-reactive carbon-carbon unsaturated bond, and R ² may be the same or different without the hydrosilylation-reactive carbon-carbon unsaturated bond. It is a substituted or unsubstituted monovalent hydrocarbon group. However, a, b, c, d, e, f, and g are numbers that satisfy a ≧ 0, b ≧ 0, c ≧ 0, d ≧ 0, e ≧ 0, f ≧ 0, and g ≧ 0, respectively. However, it is a number that satisfies b + c + e> 0 and a + b + c + d + e + f + g = 1. The sequence order of each siloxane unit is arbitrary.

Examples of the group having a hydrosilylation-reactive carbon-carbon unsaturated bond of R ¹ include a vinyl group, an allyl group, an ethynyl group, an octenyl group, a dodecenyl group, a norbornenyl group, an isonorbornenyl group, an acryloyl group and a methacryloyl group. It is preferably an alkenyl group having 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms, and a vinyl group is particularly preferable.

The organopolysiloxane of the component (A) contains at least two, preferably two to six, hydrosilylation-reactive carbon-carbon unsaturated bonds in one molecule. These groups may be located only at one of the molecular chain end and the molecular chain side chain (non-terminal of the molecular chain) of the component (A), or may be located at both of them.

The R ^2, hydrosilation reactive carbon - not particularly limited as long as it does not contain carbon unsaturated bond, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, n- butyl group, s- butyl group , Isobutyl group, t-butyl group, n-pentyl group, neopentyl group, isopentyl group, s-pentyl group, 2-pentyl group, hexyl group, heptyl group, octyl group, 2-ethylhexyl group and other alkyl groups; cyclopentyl group , Cycloalkyl group such as cyclohexyl group; aryl group such as phenyl group, trill group, xsilyl group, mesityl group, naphthyl group; aralkyl group such as benzyl group, phenethyl group; chloromethyl group, 3-chloropropyl group, trifluoro An substituent such as an alkyl halide group such as a methyl group or a 3,3,3-trifluoropropyl group, preferably having a carbon atom number of 1 to 12, more preferably 1 to 10, still more preferably 1 to 8, or not substituted. Examples thereof include a halogen-substituted monovalent hydrocarbon group, and a methyl group is particularly preferable.

Specific examples of the component (A) include both-terminal dimethylvinylsiloxy group-blocking dimethylsiloxane, both-terminal trimethylsiloxy group-blocking methylvinylsiloxane, both-terminal dimethylvinylsiloxane / cyclic methylvinylsiloxane copolymer, and cyclic methylvinylsiloxane. , Both-terminal dimethylvinylsiloxy group-blocking dimethylsiloxane / cyclic diphenylsiloxane copolymer, both-terminal dimethylvinylsiloxy group-blocking dimethylsiloxane / cyclic methylphenylsiloxane copolymer, both-terminal methylphenylvinylsiloxy group-blocking dimethylsiloxane, both-terminal methyl Phenylvinyl siloxy group-blocked diphenylsiloxane, both-terminal methylphenylvinyl siloxy group-blocked methylphenylsiloxane, both-terminal methylphenylvinylsiloxy group-blocked dimethylsiloxane / cyclic diphenylsiloxane copolymer, (CH ₂ = CH) (CH ₃ ) ₂ SiO _Examples thereof include a copolymer composed of _1/2 unit and (CH ₃ ) ₃ SiO _1/2 unit and SiO 4/2 unit. The component (A) may be used alone or in combination of two or more.

The kinematic viscosity of the component (A) is not particularly limited, but is preferably in the range of 10 to 100,000 mm ² / s, more preferably 100 to 10,000 mm ² / s. The kinematic viscosity is a value measured at 25 ° C. using an Ubbelohde viscometer. Within such a range, the handleability of the composition is excellent.

[(B) component]
The component (B) in the conductive silicone composition of the present invention acts as a cross-linking agent that crosslinks the hydrosilylation-reactive carbon-carbon unsaturated bond contained in the component (A) by a hydrosilylation reaction. The component (B) is an organohydrogenpolysiloxane having at least two hydrogen atoms (SiH groups) bonded to silicon atoms in one molecule.

As the component (B), for example, an organohydrogenpolysiloxane represented by the following average formula (2) can be used.

In formula (2), R ³ is a substituted or unsubstituted monovalent hydrocarbon group that does not contain a hydrosilylation-reactive carbon-carbon unsaturated bond and may be the same or different. However, h, i, j, k, l, m, and n are numbers that satisfy h ≧ 0, i ≧ 0, j ≧ 0, k ≧ 0, l ≧ 0, m ≧ 0, and n ≧ 0, respectively. , I + j + l> 0, and is a number satisfying h + i + j + k + l + m + n = 1. The sequence order of each siloxane unit is arbitrary.

Specific examples of R ³ ^{include the same groups as R 2} , preferably having an unsubstituted or halogen-substituted carbon atom number of 1 to 12, more preferably 1 to 10, and even more preferably 1 to 8. A monovalent hydrocarbon group is mentioned, and a methyl group is particularly preferable.

The organohydrogenpolysiloxane compound of the component (B) has at least 2, preferably 3 to 300, particularly preferably 3 to 100 hydrogen atoms bonded to silicon atoms in one molecule. When the organohydrogenpolysiloxane of the component (B) has a linear structure, these SiH groups may be located only at either the molecular chain end or the molecular chain side chain (non-terminal of the molecular chain). , May be located in both.

Specific examples of the component (B) include, for example, both-terminal dimethylhydrogensiloxy group-blocking dimethylsiloxane, both-terminal trimethylsiloxy group-blocking methylhydrogensiloxane / dimethylsiloxane copolymer, and both-terminal dimethylhydrogensiloxy group-blocking. Dimethylsiloxane / cyclic methylhydrogensiloxane copolymer, cyclic methylhydrogensiloxane, both-terminal dimethylphenylsiloxy group-blocking methylphenylhydrogensiloxane / dimethylsiloxane cyclic copolymer, both-terminal dimethylphenylsiloxy group-blocking diphenylsiloxane / methylhydro Gensiloxane copolymer, both-terminal methylphenylhydrogensiloxy group-blocking diphenylpolysiloxane, both-terminal methylphenylhydrogensiloxy group-blocking dimethylsiloxane / diphenylsiloxane / methylhydrogensiloxane copolymer, both-terminal diphenylhydrogensiloxy group-blocking Examples thereof include dimethylsiloxane / diphenylsiloxane / methylhydrogensiloxane copolymer, one-terminal methylphenylhydrogen group, one-terminal dimethylhydrogen group-blocking diphenylpolysiloxane, and the like.

The organohydrogenpolysiloxane compound of the component (B) may be used alone or in combination of two or more.

The kinematic viscosity of the component (B) is not particularly limited, but is preferably in the range of 10 to 1,000 mm ² / s, more preferably 10 to 100 mm ² / s. The kinematic viscosity can be measured at 25 ° C. using, for example, an Ubbelohde viscometer or a Canon Fenceke type viscometer. Within such a range, the handleability of the composition is excellent.

As for the blending amount of the component (B), the number of silicon atom-bonded hydrogen atoms in the component (B) is preferably 0.5 with respect to one hydrosilylation-reactive carbon-carbon unsaturated bond in the component (A). The amount is in the range of ~ 10.0, more preferably 1.0 to 6.0. Within such a range, a cured product having excellent mechanical properties can be obtained.

[Component (C)]
The component (C) in the conductive silicone composition of the present invention is a bis (β-diketonato) platinum complex, and the hydrosilylation-reactive carbon-carbon unsaturated bond in the component (A) and the component (B). Silicon atom bond Acts as a hydrosilylation catalyst to promote the hydrosilylation reaction with hydrogen atoms.

Examples of the bis (β-diketonato) platinum complex include a bis (1,3-propanedionat) platinum complex, a bis (2,4-pentandionato) platinum complex, and a bis (2,4-hexandionato) platinum complex. , Bis (2,4-heptandionat) platinum complex, bis (3,5-heptandionat) platinum complex, bis (1-phenyl-1,3-butandionato) platinum complex, bis (1,3-diphenyl-1,3) -Propanedionat) platinum complex and the like, preferably a bis (1,3-propanedionat) platinum complex.

The content of the component (C) is preferably 0.001 to 0.5 parts by mass, more preferably 0.01 to 0.1 parts by mass, as a platinum atomic mass with respect to 100 parts by mass of the component (A). preferable. Within such a range, a composition having excellent curability and storage stability can be obtained.

[(D) component]
The component (D) in the conductive silicone composition of the present invention is conductive particles.

The component (D) may be any as long as it has conductivity, and for example, metal particles such as aluminum, nickel, copper, silver, gold, platinum, and palladium, alloys thereof, or alloys thereof. Metal-plated particles, zinc oxide, titanium oxide, antimony-doped tin oxide (ATO), phosphorus-doped tin oxide (PTO), indium tin oxide (ITO), fluorine-doped tin oxide (FTO), etc. can be used and are conductive. From the viewpoint of the above, silver powder and silver-plated powder are preferable.

As the silver powder, for example, Mitsubishi Materials, Fukuda Metal Leaf Powder, Tokuriki Honten, DOWA Electronics, Tanaka Kikinzoku, etc. can be used.

The conductive particles may have any shape such as spherical, flake-shaped, dendritic, and amorphous, and may be a mixture thereof, but flake-shaped is particularly preferable. Here, the flaky shape also includes what is called a flat shape, a flaky shape, a scaly shape, or the like. The average particle size of the conductive particles is preferably in the range of 0.1 to 100 μm, more preferably in the range of 0.1 to 50 μm. If the conductive particles have an average grain shape in such a range, the uniformity of the composition can be further improved, the coatability can be further improved, and the conductivity can be further improved. In the present invention, the average particle size means a 50% cumulative diameter (median diameter) in a volume-based particle size distribution, and can be measured by, for example, Microtrac MT330OEX manufactured by Nikkiso Co., Ltd.

The tap density of the component (D) is preferably ^{1.0 to 7.0 g / cm 3.} The tap density measurement method conforms to JIS Z 2512: 2012.

The filling amount of the component (D) is preferably in the range of 50 to 99% by mass, more preferably 60 to 95% by mass, and further preferably 75 to 93% by mass with respect to the total mass of the conductive silicone composition. Is. Within such a range, a composition having excellent curability and handleability can be obtained, and sufficient conductivity can be imparted to the cured product.

[(E) component]
(E) Adhesive aid may be added to the conductive silicone composition of the present invention in order to enhance the adhesiveness to the resin. As the adhesive aid, from the viewpoint of imparting self-adhesiveness to the conductive silicone composition of the present invention, which is an addition reaction curing type, an organosilicon compound such as silane or siloxane containing a functional group that imparts adhesiveness, non-adhesive. Silicone-based organic compounds and the like are used.

Specific examples of the functional group that imparts adhesiveness include a polymerizable group having a carbon-carbon unsaturated bond bonded to a silicon atom, a SiH group, and an epoxy group bonded to a silicon atom via a carbon atom (for example, γ-). Glycydoxypropyl group, β- (3,4-epoxycyclohexyl) ethyl group, etc.), alkoxysilyl group (for example, trimethoxysilyl group, triethoxysilyl group, methyldimethoxysilyl group, etc.) and the like can be mentioned.

Examples of compounds containing at least one of the above functional groups and an organosiloxane skeleton include those represented by the following structural formulas. In the formula, Me represents a methyl group.

Examples of the non-silicone organic compound include an organic acid allyl ester compound represented by the following structural formula and an allyl ether compound.

Examples of other non-silicone adhesive aids include organic titanium compounds, organic zirconium compounds, and organoaluminum compounds.

Examples of the organic titanium compound include tetraethyl titanate, tetrapropyl titanate, tetrabutyl titanate, titanium tetraacetylacetonate, and diisopropoxytitanium bis (acetylacetonato).

Examples of organic zirconium compounds include zirconium tetraethoxyd, zirconium propoxide, zirconium butoxide, zirconium acetylacetonate, and bisacetatooxozirconium.

Examples of organoaluminum compounds include aluminum ethoxyde, aluminum propoxide, aluminum butoxide, aluminum isopropoxide, aluminum acetylacetonate, and the like.

Among these, a compound having an α-silyl ester structure is preferable, and ethyl 2-trimethoxysilylpropanoate is particularly preferable.

[Other ingredients]
<Reinforcing material>
The conductive silicone composition of the present invention may contain fine powdered silica as a reinforcing material in order to improve tensile strength, elongation, tear strength and the like. The specific surface area (BET method) of this fine powder silica is ^{preferably 50 m 2} / g or more, more preferably 50 to 400 m ² / g, and particularly preferably 100 to 300 m ² / g. When the specific surface area is 50 m ² / g or more, sufficient reinforcing property can be imparted to the cured product.

In the present invention, such fine powdered silica may be a known one that has a specific surface area within the above range (50 m ² / g or more) and has been conventionally used as a reinforcing filler for silicone rubber, for example. , Cigarette silica (dry silica), precipitated silica (wet silica) and the like. Fine powder silica may be used as it is, but in order to impart good fluidity to the composition, methylchlorosilanes such as trimethylchlorosilane, dimethyldichlorosilane and methyltrichlorosilane, dimethylpolysiloxane, hexamethyldisilazane and divinyl It is preferable to use one treated with an organosilicon compound such as hexaorganodisilazane such as tetramethyldisilazane and dimethyltetravinyldisilazane. Reinforcing silica may be used alone or in combination of two or more.

<Diluent>
The conductive silicone composition of the present invention can use a non-reactive diluent. By using a diluent, the viscosity of the composition before curing can be reduced without impairing the conductivity after curing, and workability can be improved. Examples of diluents include aromatic hydrocarbon solvents such as toluene and xylene, ester solvents such as ethyl acetate, propyl acetate, butyl acetate, pentyl acetate and propylene glycol methyl ether acetate, methyl ethyl ketone, cyclopentanone, etc. Examples thereof include ketone solvents such as methylisobutylketone, and aliphatic hydrocarbon solvents such as hexane, heptane, octane, isooctane and isododecane.

[Conductive silicone cured product]
The present invention provides a cured product of the above-mentioned conductive silicone composition having a volume resistivity of 1.0 × 10 ^-3 Ω · cm or less.
The cured product of the conductive silicone composition of the present invention preferably has a volume resistivity of 1.0 × 10 ^-3 Ω · cm or less. Such a conductive silicone cured product has sufficient conductivity as well as flexibility and extensibility, and is useful for mounting electronic components and elements on a substrate, forming an electronic circuit by printing, and the like. Become. The lower limit of the volume resistivity is not particularly limited, ^{but can be 1.0 × 10 -5} Ω · cm or more.

[Laminate]
The present invention provides a laminate having the above-mentioned conductive silicone cured product.
The conductive silicone composition of the present invention can form a highly conductive laminate by, for example, applying or printing on a substrate and then curing. The base material is not particularly limited, and for example, (meth) acrylic resin, epoxy resin, high-density polyethylene resin, low-density polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyacrylonitrile resin, etc. Organic materials such as polycarbonate resin, polyurethane resin, polyester resin, polyamide resin, polyimide resin, polyacetal resin, polyethylene oxide resin, polyetherimide resin, polyethersulfone resin, polyetheretherketone resin, polyphenylene sulfide resin, silicone resin, and alumina. , Zirconia, barium titanate, silicon nitride, aluminum nitride, silicon carbide, glass, metals and other inorganic materials can be used.

As a pretreatment for applying or printing the conductive silicone of the present invention, surface treatment may be performed on the above-mentioned various base materials. Specific examples of the surface treatment include irradiation of active energy rays such as ultraviolet rays, X-rays, γ-rays, α-rays, β-rays, and electron beams, plasma treatment, corona treatment, ozone treatment, and the like.

[Applying method]
The conductive silicone composition of the present invention can be used on a substrate, for example, by printing methods such as mesh screen printing, metal mask printing, gravure printing, offset printing, reverse offset printing, flexo printing, inkjet printing, roller coater, slit coater. , Dispenser, dipping and other coating methods.

[Manufacturing method of conductive silicone cured product]
Further, the present invention provides a method for producing the above-mentioned conductive silicone cured product, which is a method for producing the above-mentioned conductive silicone cured product, which cures the above-mentioned conductive silicone composition at a temperature of 80 to 150 ° C.
The conductive silicone composition of the present invention is preferably cured by heating at 80 to 150 ° C., particularly 100 to 120 ° C. for 10 to 120 minutes. Within such a range, curing progresses sufficiently, and it is possible to prevent the composition from becoming brittle.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited thereto. The viscosity at 25 ° C. was measured with a rotational viscometer, and the kinematic viscosity at 25 ° C. was measured with an Ubbelohde viscometer or a Canon Fenceke type viscometer.

[Examples 1 to 4, Comparative Examples 1 to 5]
The components (A) to (E) and other components shown below are mixed in the blending amounts shown in Tables 1 and 2 using a rotation / revolution mixer (manufactured by THINKY Co., Ltd.) for 5 minutes. A silicone composition was prepared. The numerical values of each component in Table 1 or Table 2 indicate parts by mass. The silver powder filling factor is the mass percentage of silver powder in the entire composition.

[(A) component]
a-1: Both-terminal dimethylvinylsilyl group-blocking dimethylpolysiloxane compound (kinematic viscosity at 25 ° C., 600 mm ² / s).
a-2: An organopolysiloxane having a weight average molecular weight of 4,500 represented by the following average formula (3).

In the formula, Vi represents a vinyl group and Me represents a methyl group.

[(B) component]
b-1: Organohydrogenpolysiloxane compound represented by the following structural formula.
(In the formula, the sequence order of the siloxane units in parentheses is indefinite.)

[Component (C)]
c-1: A butyl carbitol acetate solution of a bis (1,3-propanedionate) platinum complex (containing 0.5% by mass as a platinum atom) (manufactured by Umicore).
c-2: Toluene solution of (methylcyclopentadienyl) trimethyl platinum complex (containing 0.5% by mass as a platinum atom) (manufactured by Umicore).
c-3: A dimethylpolysiloxane (viscosity 600 mPa · s) solution (containing 1.0% by mass as a platinum atom) of the reaction product of hexachloride platinum acid and 1,3-divinyltetramethyldisiloxane.

[(D) component]
d-1: Silver powder having an average particle size of 5.8 μm and a tap density of 5.3 g / cm ^3.

[(E) component]
e-1: Ethyl 2-trimethoxysilylpropanoate.
e-2: A compound represented by the following structural formula (Me represents a methyl group in the formula).

e-3: A compound represented by the following structural formula (Me represents a methyl group in the formula).

[Other ingredients]
f-1: 1-ethynyl-1-cyclohexanol (manufactured by Nisshin Chemical Industry Co., Ltd., reaction control agent).

The characteristics of the conductive silicone composition and its cured product were evaluated as follows.

[Curability in the atmosphere]
The silicone compositions of Examples 1 to 4 and Comparative Examples 1 to 4 were squeezed onto a slide glass to a thickness of 100 μm, respectively, and heated in an oven at 120 ° C. for 1 hour in the air to determine the presence or absence of curing. confirmed. At this time, the case where the silicone composition was completely cured was evaluated as "◯", the case where it was partially uncured was evaluated as "Δ", and the case where almost no curing was observed was evaluated as "x". The results are shown in Tables 1 and 2.

[Curability at the time of bonding]
1 g of each of the silicone compositions of Examples 1 to 4 and Comparative Examples 1 to 4 was placed on an aluminum piece, and the aluminum pieces were laminated so as to have a thickness of 2 mm. After heating in an oven at 120 ° C. for 1 hour in the atmosphere, this was peeled off to confirm the curability of the inside. At this time, the case where the silicone composition was completely cured was evaluated as "◯", the case where it was partially uncured was evaluated as "Δ", and the case where almost no curing was observed was evaluated as "x". The results are shown in Tables 1 and 2.

[Volume resistivity]
The volume resistivity of the cured product prepared in the above atmospheric heat curability test was measured by the four-probe method using the Lorester GX manufactured by Mitsubishi Chemical Analytech. The results are shown in Tables 1 and 2.

[Preservation]
1 g of each of the silicone compositions of Examples 1 to 3 and Comparative Examples 1 to 4 was placed in a container, and the presence or absence of curing under the storage conditions of 25 ° C. and 40 ° C. was confirmed every 12 hours. The results are shown in Table 1. In Example 4, the presence or absence of curing after storage at 40 ° C. for 100 hours was confirmed, and the volume resistivity after storage was measured based on the above method. The results are shown in Table 2.

As shown in Tables 1 and 2, the conductive silicone compositions of Examples 1 to 4 have good curability at the time of bonding and are excellent in storage stability even though no reaction control agent is added. It is a material.

On the other hand, in Comparative Example 1, a different kind of photoactive hydrosilylation catalyst is used instead of the component (C) of the present invention, and the curability is good, but the storage stability is extremely low. In Comparative Example 2, a general hydrosilylation catalyst and a reaction control agent are used, and although the storage stability is excellent, the curability at the time of bonding is remarkably inferior. In Comparative Example 3, the curability at the time of bonding was improved by reducing the amount of the reaction control agent of Comparative Example 2, but the result was that the storage stability was impaired. In Comparative Example 4 in which both the hydrosilylation catalyst and the reaction control agent of Comparative Example 2 were reduced, the storage stability was improved, but the curability was not sufficient. In Comparative Example 5, since the reaction control agent was not contained in the general hydrosilylation catalyst, the storage stability was inferior, and curing occurred immediately after mixing.

The present invention is not limited to the above embodiment. The above-described embodiment is an example, and any object having substantially the same configuration as the technical idea described in the claims of the present invention and exhibiting the same effect and effect is the present invention. Is included in the technical scope of.

Claims

(A) An organopolysiloxane having two or more groups having a hydrosilylation-reactive carbon-carbon unsaturated bond in one molecule.
(B) Organohydrogenpolysiloxane having two or more SiH groups in one molecule,
(C) Bis (β-diketonato) platinum complex,
(D) Conductive particles,
A conductive silicone composition comprising.
The conductive silicone composition according to claim 1, wherein the group having the hydrosilylation-reactive carbon-carbon unsaturated bond in the component (A) is an alkenyl group having 2 to 10 carbon atoms.
The number of SiH groups in the component (B) is 0.5 to 10.0 for each hydrosilylation-reactive carbon-carbon unsaturated bond in the component (A). The conductive silicone composition according to claim 1 or 2.
The conductive silicone composition according to any one of claims 1 to 3, wherein the content of the component (D) is 50 to 99% by mass with respect to the total mass of the composition.
The conductive silicone composition according to any one of claims 1 to 4, wherein the component (D) is silver powder.
The conductive silicone composition according to any one of claims 1 to 5, further comprising (E) an adhesive aid.
The conductive silicone composition according to claim 6, wherein the component (E) contains a compound having an α-silyl ester structure.
The cured product of the conductive silicone composition according to any one of claims 1 to 7, characterized in that the volume resistivity is 1.0 × 10 -3 Ω · cm or less. Conductive silicone cured product.
The method for producing a conductive silicone cured product according to claim 8, wherein the conductive silicone composition is cured at a temperature of 80 to 150 ° C.
A laminate characterized by having the conductive silicone cured product according to claim 8.