JP6722766B2 - Conductive resin particles and uses thereof - Google Patents

Description

The present invention relates to conductive resin particles and uses thereof. More specifically, the present invention is a conductive resin particle and its use (conductive resin composition, which can be preferably used in an application for the purpose of expressing the conductivity by bringing the conductive resin particles into close contact with each other. Coating agent, film, and gap material).

There is known an electronic circuit board in which a conductive paste in which conductive particles are dispersed in a binder resin is interposed between electrodes to improve connection reliability between the electrodes. Hitherto, as such conductive particles, conductive particles made of metal such as gold, silver and nickel have been used. However, since such conductive particles have a non-uniform shape or have a larger specific gravity than a binder resin, it is difficult to settle in the conductive paste or to uniformly disperse the conductive particles in the conductive paste uniformly. Therefore, it was not reliable.

Therefore, a core particle made of organic particles, a conductive layer formed on the surface of the core particle, and a conductive particle powder further containing a conductive polymer, wherein the conductive layer is a metal or metal oxide A conductive particle powder composed of one kind or two or more kinds of conductive fillers selected from materials or alloys is disclosed (Patent Document 1).

Japanese Patent No. 5630596

However, since the conductive particle powder has a hard conductive layer made of one or more conductive fillers selected from metals, metal oxides or alloys, the conductive resin particles are compressed. When the conductive resin particles are brought into close contact with each other, the adhesiveness between the conductive resin particles and the close contact between the conductive member (for example, the electrode) and the conductive resin particles that are electrically connected by the conductive resin particles Since the property is low and the contact area between the conductive resin particles and the contact area between the conductive member and the conductive resin particles are small, the resistance at the time of compression is high and a good conductivity cannot be obtained.

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to provide a conductive resin particle having a good conductivity and a conductive resin composition using the same, a coating agent, a film, and a gap material. To provide.

Therefore, as a result of intensive studies by the present inventors in order to solve the above problems, 10% compression was achieved in a conductive resin particle having a core particle made of a polymer and a shell made of a conductive polymer coating the core particle. It was found that conductive resin particles having good conductivity can be obtained by setting the compressive strength at the time of deformation to 0.1 to 30 MPa, and completed the present invention.

That is, the conductive resin particles of the present invention is a conductive resin particle having a core particle made of a polymer and a shell made of a conductive polymer coating the core particle in order to solve the above problems. The compressive strength at 10% compression deformation is 0.1 to 30 MPa.

According to the configuration of the present invention, since the core particles and the shell are both made of a polymer and the compressive strength at 10% compression deformation is 30 MPa or less, the conductive resin particles are soft and largely deformed at the time of compression. Therefore, when the conductive resin particles are compressed to bring the conductive resin particles into close contact with each other, the adhesiveness between the conductive resin particles or the conductive member that is going to be electrically connected by the conductive resin particles (for example, Since the adhesion between the electrode) and the conductive resin particles is improved, and the contact area between the conductive resin particles and the contact area between the conductive member and the conductive resin particles are increased, the resistance during compression can be reduced. Therefore, good conductivity can be obtained.

The electrically conductive resin composition of the present invention is characterized by containing the electrically conductive resin particles of the present invention and a matrix resin in order to solve the above problems.

Since the conductive resin composition having the above structure contains the conductive resin particles of the present invention having good conductivity, by molding the conductive resin composition having the above structure, excellent conductivity and antistatic properties are obtained. A molded product can be obtained.

The coating agent of the present invention is characterized by containing the conductive resin particles of the present invention and a binder resin in order to solve the above problems.

Since the coating agent having the above-mentioned configuration contains the conductive resin particles of the present invention having good conductivity, by applying the coating agent having the above-mentioned configuration onto a substrate, a conductive product (for example, a conductive film) or A product that can be suitably used as an antistatic product (for example, an antistatic film) can be obtained.

The film of the present invention is characterized by containing the conductive resin particles of the present invention in order to solve the above problems.

Since the film having the above-mentioned structure contains the conductive resin particles of the present invention having good conductivity, it can be suitably used as a conductive film or an antistatic film.

The gap material of the present invention is characterized by containing the conductive resin particles of the present invention in order to solve the above problems.

Since the gap material having the above structure contains the conductive resin particles of the present invention having good conductivity, it has conductivity and exhibits an antistatic function.

INDUSTRIAL APPLICABILITY The present invention has an effect of providing conductive resin particles having good conductivity, and a conductive resin composition, a coating agent, a film, and a gap material using the conductive resin particles.

Hereinafter, the present invention will be described in detail.
[Conductive resin particles]
The conductive resin particle of the present invention is a conductive resin particle having a core particle made of a polymer and a shell made of a conductive polymer coating the core particle, and has a compressive strength at 10% compression deformation. It is 0.1 to 30 MPa.

The compressive strength of the conductive resin particles at 10% compression deformation is 0.1 to 30 MPa, and preferably 0.1 to 17 MPa. The conductive resin particles having a compressive strength at 10% compression deformation of less than 0.1 MPa have poor mechanical strength and may be broken during use. The conductive resin particles having a compressive strength of 17 MPa or less when compressed and deformed by 10% have an adhesive property between the conductive resin particles and a conductive property when the conductive resin particles are compressed to bring the conductive resin particles into close contact with each other. Adhesiveness between a conductive member (for example, an electrode) and the conductive resin particles to be electrically connected by the conductive resin particles is further improved, the contact area between the conductive resin particles and the conductive member and the conductive resin particles Since the contact area is further increased, the resistance at the time of compression can be further reduced, and further excellent conductivity can be obtained. In the present application, "compressive strength at 10% compressive deformation" means the compressive strength at 10% compressive deformation (hereinafter referred to as "10% compressive strength") obtained by the measuring method described in the section of Examples below. Referred to as).

The conductive resin particles preferably have a volume average particle diameter of 1 to 200 μm. When the conductive resin particles have a volume average particle diameter of 1 μm or more, dispersibility in various solvents when used in a conductive paste or the like is improved, and good handleability can be obtained. Since the conductive resin particles have a volume average particle diameter of 200 μm or less, when the conductive resin particles are brought into close contact with each other or when the conductive member and the conductive resin particles are brought into close contact with each other, The mutual contact is improved, and more conductive paths can be obtained. In the present application, the “volume average particle diameter” means the volume average particle diameter obtained by the measuring method described in the section of Examples below.

The variation coefficient of the volume-based particle diameter of the conductive resin particles is preferably 10% or more, and more preferably 20% to 50%. Conductive resin particles having a volume-based particle diameter variation coefficient of 10% or more (particularly 20% or more) are compared with conductive resin particles having the same composition and a volume-based particle diameter variation coefficient of 15% or less. When the conductive resin particles are compressed and brought into close contact with each other, since the conductive resin particles contain many conductive resin particles having a fine particle diameter (a particle diameter significantly smaller than the volume average particle diameter). A large number of conductive resin particles having a small particle size enter between the other conductive resin particles to improve the filling rate. Therefore, the adhesiveness between the conductive resin particles and the adhesiveness between the conductive member (for example, an electrode) and the conductive resin particles that are electrically connected by the conductive resin particles are improved, and the conductive resin particles are electrically connected to each other. Since the contact area between the above and the contact area between the conductive member and the conductive resin particles are increased, the resistance at the time of compression can be reduced, and more excellent conductivity can be obtained. In addition, in the present application documents, “variation coefficient of volume-based particle size” in the present application document means a variation coefficient of volume-based particle size obtained by a measuring method described in the section of Examples described later. It shall be.

The restoration rate of the conductive resin particles is preferably 15% or more and less than 30%, more preferably 15% or more and 25% or less, and further preferably 15% or more and 20% or less. When the restoration rate of the conductive resin particles is 15% or more, the shape of the conductive resin particles is restored and the conductive resin is restored even when the compressive stress is reduced after the conductive resin particles are compressed. Adhesion between particles can be maintained. Therefore, good conductivity can be stably obtained. When the restoration rate of the conductive resin particles is less than 30%, the shape of the conductive resin particles after being compressed can be easily maintained, and as a result, good adhesion can be maintained.

The conductivity of the conductive resin particles of the present invention is preferably 5.0×10 ^{−3 to} 5.0×10 ⁻¹ (S/cm), and 9×10 ⁻³ to 1×10 ⁻¹ ( S/cm) is more preferable, and 1×10 ^{−2 to} 5×10 ⁻² (S/cm) is further preferable. When the conductivity of the conductive resin particles is at least the lower limit of the above range, conductive resin particles having good conductivity can be realized.

[Core particles]
The core particle may be a condensation polymer such as polyurethane or silicone polymer, but is preferably a polymer of vinyl monomer. The vinyl monomer may be a compound having at least one ethylenically unsaturated group (broadly defined vinyl group), and is a monofunctional vinyl monomer having one ethylenically unsaturated group. It may be a polyfunctional vinyl-based monomer having two or more ethylenically unsaturated groups.

Examples of the monofunctional vinyl-based monomer include, for example, monofunctional (meth)acrylic acid ester monomers, which will be described later in detail; styrene-based monomers such as styrene, p-methylstyrene, α-methylstyrene; acetic acid. Examples thereof include vinyl ester monomers such as vinyl. Of these, monofunctional (meth)acrylic acid ester monomers are preferred as monofunctional vinyl-based monomers. In addition, in this application document, "(meth)acrylic acid" means acrylic acid and/or methacrylic acid, and "(meth)acrylate" means acrylate and/or methacrylate.

（式中、Ｒ_１は水素又はメチル基であり、ｎは１〜４の整数である。）で示される単量体、一般式（II）で示す単量体、下記一般式（II）

（式中、Ｒ_２は水素又はメチル基であり、ｍは５〜１５の整数である。）で示される単量体、１，３−ブチレングリコールジ（メタ）アクリレート、１，４−ブタンジオールジ（メタ）アクリレート、１，６−ヘキサンジオールジ（メタ）アクリレート、グリセリンジ（メタ）アクリレート、トリメチロールプロパントリ（メタ）アクリレート、ペンタエリスリトールテトラ（メタ）アクリレート、フタル酸ジエチレングリコールジ（メタ）アクリレート、カプロラクトン変性ジペンタエリスルトールヘキサ（メタ）アクリレート、カプロラクトン変性ヒドロキシピバリン酸エステルネオペンチルグリコールジアクリレート、ポリエステルアクリレート、ウレタンアクリレートオリゴマー（後段で詳細に説明する）等の２個以上のエチレン性不飽和基を有する多官能（メタ）アクリル酸エステル系単量体；ジビニルベンゼン、ジビニルナフタレン、これらの誘導体等の芳香族ジビニル系単量体等が挙げられる。これらのうち、上記一般式（Ｉ）で示す単量体、上記一般式（II）で示す単量体、及びウレタンアクリレートが好ましい。これらビニル系単量体は、それぞれ単独で、又は２種類以上を組み合わせて用いることができる。The polyfunctional vinyl-based monomer is represented by the following general formula (I)

(In the formula, R ₁ is hydrogen or a methyl group, and n is an integer of 1 to 4.) A monomer represented by the general formula (II), a general formula (II) shown below.

(In the formula, R ₂ is hydrogen or a methyl group, and m is an integer of 5 to 15.), 1,3-butylene glycol di(meth)acrylate, 1,4-butanediol. Di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, glycerin di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, diethylene glycol di(meth)acrylate phthalate , Two or more ethylenic unsaturations such as caprolactone-modified dipentaerythritol hexa(meth)acrylate, caprolactone-modified hydroxypivalic acid ester neopentyl glycol diacrylate, polyester acrylate, urethane acrylate oligomer (described in detail later) Examples thereof include polyfunctional (meth)acrylic acid ester-based monomers having a group; aromatic divinyl-based monomers such as divinylbenzene, divinylnaphthalene, and derivatives thereof. Among these, the monomer represented by the general formula (I), the monomer represented by the general formula (II), and urethane acrylate are preferable. These vinyl monomers can be used alone or in combination of two or more kinds.

（式中、Ｒ_１は水素又はメチル基であり、ｎは１〜４の整数である。）で示される単量体とを含む単量体混合物（ビニル系単量体）の重合体を含んでいることが好ましい。この重合体は、架橋構造を有する重合体であるため、コア粒子に復元性を付与できる。したがって、この重合体が上記コア粒子に含まれていることにより、良好な復元率を有する導電性樹脂粒子を実現できる。The core particles are composed of a monofunctional (meth)acrylic acid ester monomer and the following general formula (I).

(In the formula, R ₁ is hydrogen or a methyl group, and n is an integer of 1 to 4.) A polymer of a monomer mixture (vinyl-based monomer) is included. Is preferred. Since this polymer is a polymer having a cross-linked structure, it is possible to impart resilience to the core particles. Therefore, by including this polymer in the core particles, it is possible to realize conductive resin particles having a good restoration rate.

The monofunctional (meth)acrylic acid ester monomer is not particularly limited, and examples thereof include methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, 2-acrylic acid acrylate. Acrylic esters such as ethylhexyl; methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, isobornyl methacrylate, 2-hydroxyethyl methacrylate, 2-methoxyethyl methacrylate, glycidyl methacrylate, methacrylic acid. Methacrylic acid esters such as tetrahydrofurfuryl acid, diethylaminoethyl methacrylate, trifluoroethyl methacrylate, heptadecafluorodecyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate, and alkylene oxide groups. Any of the (meth)acrylic acid esters (described in detail later) and the like can be used. These monofunctional (meth)acrylic acid ester monomers can be used alone or in combination of two or more kinds.

Among the above monofunctional (meth)acrylic acid ester monomers, an alkyl acrylate having an alkyl group having 1 to 12 carbon atoms is preferable, and an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms is more preferable. By using such an alkyl acrylate, the 10% compressive strength of the core particles can be lowered, so that it is easy to realize the conductive resin particles having the 10% compressive strength equal to or lower than the upper limit of the above range.

In addition, the content of the monofunctional (meth)acrylic acid ester monomer in the monomer mixture is preferably 70 to 99 parts by weight with respect to 100 parts by weight of the monomer mixture. By setting the content of the monofunctional (meth)acrylic acid ester monomer within the above range, it becomes easy to realize the conductive resin particles having the restoration ratio in the above range.

Examples of the monomer represented by the general formula (I) include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, and tetraethylene glycol di(meth)acrylate. Are listed. Among these monomers represented by the general formula (I), ethylene glycol di(meth)acrylate is particularly preferable, and when ethylene glycol di(meth)acrylate is used as the monomer represented by the general formula (I), The solvent resistance of the conductive resin particles can be improved more effectively with respect to the amount added.

The content of the monomer represented by the general formula (I) in the monomer mixture is preferably 1 to 30 parts by weight with respect to 100 parts by weight of the monomer mixture. By setting the content of the monomer represented by the general formula (I) within the above range, it becomes easy to realize the conductive resin particles having the restoration ratio in the above range.

（式中、Ｒ_２は水素又はメチル基であり、ｍは５〜１５の整数である。）で示される単量体をさらに含む単量体混合物の重合体であることが好ましい。これにより、上記コア粒子に含まれる重合体に柔軟な架橋構造を導入できるため、導電性樹脂粒子の１０％圧縮強度を低くすることができ、また、導電性樹脂粒子の復元率を向上させることができる。したがって、前述した範囲の上限以下の１０％圧縮強度を有する導電性樹脂粒子を実現しやすくなり、また、前述した範囲の下限以上の復元率を有する導電性樹脂粒子を実現しやすくなる。The polymer of the monomer mixture contained in the core particles has the following general formula (II) in addition to the monofunctional (meth)acrylic acid ester monomer and the monomer represented by the general formula (I). )

(In the formula, R ₂ is hydrogen or a methyl group, and m is an integer of 5 to 15.) It is preferably a polymer of a monomer mixture further containing a monomer. As a result, a flexible crosslinked structure can be introduced into the polymer contained in the core particles, so that the 10% compressive strength of the conductive resin particles can be lowered, and the recovery rate of the conductive resin particles can be improved. You can Therefore, it becomes easy to realize the conductive resin particles having a 10% compressive strength equal to or lower than the upper limit of the above range, and also to easily realize the conductive resin particles having a restoration ratio equal to or higher than the lower limit of the above range.

Examples of the monomer represented by the general formula (II) include pentaethylene glycol di(meth)acrylate, hexaethylene glycol di(meth)acrylate, heptaethylene glycol di(meth)acrylate, octaethylene glycol di(meth). ) Acrylate, nonaethylene glycol di(meth)acrylate, decaethylene glycol di(meth)acrylate, tetradecaethylene glycol di(meth)acrylate, pentadecaethylene glycol di(meth)acrylate and the like. Among the monomers represented by the general formula (II), m in the general formula (II) is nonaethylene glycol di(meth)acrylate (m=9) and tetradecaethylene glycol di(meth)acrylate (m= 14), that is, when a monomer having m in the general formula (II) within the range of 9 to 14 is used, a conductive resin having a compressive strength of 10% within the above range. It is easy to realize particles, and it is also easy to realize conductive resin particles having a recovery rate within the above range.

The content of the monomer represented by the general formula (II) in the monomer mixture is preferably 1 to 20 parts by weight, and 10 to 20 parts by weight with respect to 100 parts by weight of the monomer mixture. More preferably, it is a part. By setting the content of the monomer represented by the general formula (II) within the above range, it becomes easy to realize the conductive resin particles having 10% compressive strength within the above range, and the restoration of the above range is possible. It becomes easy to realize a conductive resin particle having a high rate.

The monomer mixture may contain a monomer other than the above-mentioned monomers. For example, the above-mentioned monomer mixture may contain another monofunctional vinyl-based monomer copolymerizable with the monofunctional (meth)acrylic acid ester monomer. Examples of the other monofunctional vinyl-based monomer copolymerizable with the monofunctional (meth)acrylic acid ester monomer include the styrene-based monomer described above and the vinyl ester-based monomer described above. .. These other monofunctional vinyl monomers can be used alone or in combination of two or more kinds.

Further, the above-mentioned monomer mixture may contain a polyfunctional vinyl-based monomer other than those represented by the general formula (I) and the general formula (II). Examples of other polyfunctional vinyl-based monomers include the above-mentioned polyfunctional (meth)acrylic acid ester-based monomers and the above-mentioned aromatic divinyl-based monomers.

Further, the vinyl-based monomer preferably contains, as a part thereof, a monomer having a hydrophilic group such as a carboxy group and a hydroxy group, and contains a (meth)acrylic acid ester having an alkylene oxide group. Is more preferable. This makes it possible to impart hydrophilicity to the surface of the core particle even when the hydrophobicity of the portion of the core particle derived from another component of the vinyl-based monomer is high. As a result, when the shell is formed by the oxidative polymerization of the monomer in the dispersion liquid in which the core particles are dispersed in the aqueous medium, the core particles can be easily dispersed in the aqueous medium to the primary particles, which is easy. In addition, individual core particles can be coated with a shell. Examples of the (meth)acrylic acid ester having such an alkylene oxide group include compounds represented by the following general formula.

In the above general formula, R ₃ represents H or CH ₃ , and R ₄ and R ₅ are different from each other and represent an alkylene group selected from C ₂ H ₄ , C ₃ H ₆ , C ₄ H ₈ , and C ₅ H _10. , P is 0 to 50, q is 0 to 50 (however, p and q do not become 0 at the same time), and R ₆ represents H or CH ₃ .

When p is greater than 50 and q is greater than 50 in the monomer of the above general formula, polymerization stability may be deteriorated and coalesced particles may be generated. The preferred range of p and q is 0 to 30, and the more preferred range of p and q is 0 to 15.

As the (meth)acrylic acid ester having an alkylene oxide group, commercially available products can be used. Examples of commercially available products include the BLEMMER (registered trademark) series manufactured by NOF CORPORATION. Further, in the Blemmer (registered trademark) series, Blemmer (registered trademark) 50PEP-300 (R ₃ is CH ₃ , R ₄ is C ₂ H ₅ , R ₅ is C ₃ H ₆ , and p and q are p on average. mixtures = 3.5 and q = 2.5, _{R 6} is H), Blemmer (TM) 70PEP-350B _{(R 3} is _CH 3, _{R 4} is _C 2 _{H 5, R} 5 is _C 3 H ₆ , p and q are on average a mixture of p=3.5 and q=2.5, R ₆ is H), Bremmer® PP-1000 (R ₃ is CH ₃ and R ₄ Is C ₂ H ₅ , R ₅ is C ₃ H ₆ , p is 0, q is a mixture of 4 to 6 on average, R ₆ is H), and Bremmer (registered trademark) PME-400 (R ₃ is CH). is _{3, R 4} is _C 2 _{H 5, R} 5 is a mixture of _C 3 _H 6, p is on average 9, q is 0, _{R 6} is CH ₃₎ and the like are suitable.

The amount of the (meth)acrylic acid ester having an alkylene oxide group used is preferably 40% by weight or less, more preferably 1 to 15% by weight, based on the total amount of the vinyl-based monomer. -10 wt% is more preferable, and 3-7 wt% is particularly preferable. When the amount of the (meth)acrylic acid ester having an alkylene oxide group used is at least the lower limit of the above range, it becomes easier to disperse the core particles in the aqueous medium into the primary particles. When the amount of the (meth)acrylic acid ester having an alkylene oxide group used exceeds 40% by weight with respect to the total amount of the polymerizable vinyl-based monomer, the polymerization stability may decrease and the number of coalesced particles may increase. ..

It is also preferable that the vinyl-based monomer contains a urethane acrylate oligomer as a polyfunctional vinyl-based monomer together with a monofunctional vinyl-based monomer such as a (meth)acrylic acid ester monomer. This makes it possible to reduce the 10% compressive strength of the core particles, and thus it is easy to realize the conductive resin particles having the 10% compressive strength equal to or lower than the upper limit of the above range. The urethane acrylate oligomer preferably exhibits a glass transition temperature (Tg) (measured from viscoelasticity) of 0 to 30° C. when cured alone. If the Tg is less than 0°C, the core particles may become tacky. When Tg is 30° C. or lower, conductive resin particles having high resilience can be obtained. The Tg when the urethane acrylate oligomer alone is cured is more preferably 0 to 28°C, further preferably 0 to 25°C.

The urethane acrylate oligomer preferably has a pencil hardness of H to HB when cured alone. When such a urethane acrylate oligomer is used, conductive resin particles having a higher restoration rate can be obtained.

Examples of commercially available products of the urethane acrylate oligomer include “New Frontier (registered trademark) RST-402” and “New Frontier (registered trademark) RST-” of New Frontier (registered trademark) RST series manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd. 201" and other new frontier (registered trademark) series urethane acrylate oligomers, UF series "UF-A01P" manufactured by Kyoeisha Chemical Co., Ltd., and the like.

[Method for producing core particles]
When the core particle of the present invention is made of a vinyl monomer polymer, it can be obtained by polymerizing a vinyl monomer. As the polymerization method, known methods for obtaining resin particles such as emulsion polymerization, dispersion polymerization, suspension polymerization, and seed polymerization can be used.

[Method for producing core particles by suspension polymerization]
The suspension polymerization is a method of polymerizing vinyl monomers in an aqueous medium. Examples of the aqueous medium include water and a mixture of water and a water-soluble organic solvent (for example, a lower alcohol having 5 or less carbon atoms).

The suspension polymerization may be carried out in the presence of a polymerization initiator, if necessary. Examples of the polymerization initiator include benzoyl peroxide, lauroyl peroxide, octanoyl peroxide, benzoyl orthochloroperoxide, methyl ethyl ketone peroxide, diisopropyl peroxydicarbonate, cumene hydroperoxide, and t-butyl hydroperoxide. Peroxide; oil-soluble azo compounds such as 2,2′-azobisisobutyronitrile and 2,2′-azobis(2,4-dimethylvaleronitrile) are mentioned. These polymerization initiators can be used alone or in combination of two or more kinds. The amount of the polymerization initiator used is about 0.1 to 1 part by weight per 100 parts by weight of the vinyl monomer.

Further, the suspension polymerization may be carried out in the presence of a dispersant and/or a surfactant, if necessary. Examples of the dispersant include poorly water-soluble inorganic salts such as calcium phosphate and magnesium pyrophosphate; water-soluble polymers such as polyvinyl alcohol, methyl cellulose, and polyvinylpyrrolidone.

Examples of the surfactant include anionic surfactants such as sodium oleate, sodium lauryl sulfate, sodium dodecylbenzene sulfonate, alkylnaphthalene sulfonate, alkyl phosphate ester salt; polyoxyethylene alkyl ether, polyoxy Nonionic surfactants such as ethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxysorbitan fatty acid ester, polyoxyethylene alkylamine, glycerin fatty acid ester; amphoteric surfactants such as lauryl dimethylamine oxide Can be mentioned.

The above dispersants and surfactants can be used alone or in combination of two or more. Among them, from the viewpoint of dispersion stability, it is preferable to use a combination of a sparingly water-soluble phosphate dispersant such as calcium phosphate or magnesium pyrophosphate, and an anionic surfactant such as alkyl sulfate or alkylbenzene sulfonate. ..

The amount of the dispersant used is preferably 0.5 to 10 parts by weight with respect to 100 parts by weight of the vinyl-based monomer, and the amount of the surfactant used is 0 with respect to 100 parts by weight of the aqueous medium. It is preferably 0.01 to 0.2 parts by weight.

The suspension polymerization is to prepare an oil phase containing the vinyl monomer, and heat the aqueous phase in which the oil phase is dispersed while dispersing the prepared oil phase in the aqueous phase containing the aqueous medium. Can be started by When a polymerization initiator is used, the vinyl phase monomer is mixed with the polymerization initiator to prepare an oil phase. When a dispersant and/or a surfactant is used, the dispersant and/or the surfactant is mixed with an aqueous medium to prepare an aqueous phase. The volume average particle diameter of the core particles can be appropriately controlled by adjusting the mixing ratio of the oil phase and the aqueous phase, the amount of the dispersant and the surfactant used, the stirring conditions, and the dispersion conditions.

As a method for dispersing the oil phase in the water phase, for example, a method in which the oil phase is directly added to the water phase and the oil phase is dispersed as droplets in the water phase by stirring force of a propeller blade or the like; A method of directly adding an oil phase to a water phase and dispersing the oil phase in the water phase using a homomixer, which is a disperser using a high shear force composed of a rotor and a stator; And a method of dispersing the oil phase in the aqueous phase by using an ultrasonic disperser or the like. Of these, the oil phase was directly added to the aqueous phase, and a high-pressure disperser such as Microfluidizer or Nanomizer (registered trademark) was used to collide the droplets of the mixture with each other or the mixture against the machine wall. To disperse the oil phase as droplets in the water phase; by dispersing the oil phase into the water phase through an MPG (microporous glass) porous membrane It is preferable because the diameters can be made more uniform.

The polymerization temperature is preferably about 40 to 90°C. The time for maintaining this polymerization temperature is preferably about 0.1 to 10 hours. The polymerization reaction may be carried out in an inert gas atmosphere such as a nitrogen atmosphere, which is inert to the reaction product (oil phase) in the polymerization reaction system. When the boiling point of the vinyl-based monomer is around the polymerization temperature or lower than the polymerization temperature, pressure-resistant polymerization equipment such as an autoclave is used to prevent the vinyl-based monomer from volatilizing under a closed or pressurized condition. It is preferable to carry out suspension polymerization in.

After the completion of the polymerization reaction, the dispersant is decomposed and removed with an acid or the like, if desired, and filtration, washing with water, dehydration, drying, pulverization, classification and the like can be carried out to obtain the target core particles.

[Method for producing core particles by seed polymerization]
In the method for producing core particles by the seed polymerization method, first, seed particles are added to an aqueous emulsion composed of a vinyl monomer and an aqueous medium. Examples of the aqueous medium include water and a mixed medium of water and a water-soluble solvent (for example, a lower alcohol having 5 or less carbon atoms).

The aqueous medium preferably contains a surfactant. As the surfactant, any of an anionic surfactant, a cationic surfactant, a nonionic surfactant, and a zwitterionic surfactant can be used.

Examples of the anionic surfactant include sodium oleate, fatty acid soap such as castor oil potassium soap, sodium lauryl sulfate, alkyl sulfate ester salt such as ammonium lauryl sulfate, alkylbenzene sulfonate such as sodium dodecylbenzenesulfonate, alkyl Naphthalene sulfonate, alkane sulfonate, dialkyl sulfosuccinate such as sodium di(2-ethylhexyl) sulfosuccinate, alkernyl succinate (dipotassium salt), alkyl phosphate ester salt, naphthalene sulfonic acid formalin condensate, poly Examples thereof include polyoxyethylene alkyl phenyl ether sulfate, polyoxyethylene alkyl ether sulfate such as sodium polyoxyethylene lauryl ether sulfate, and polyoxyethylene alkyl sulfate.

Examples of the above-mentioned cationic surfactant include alkylamine salts such as laurylamine acetate and stearylamine acetate, and quaternary ammonium salts such as lauryltrimethylammonium chloride.

Examples of the zwitterionic surfactant include lauryl dimethylamine oxide and phosphoric acid ester-based or phosphorous acid ester-based surfactants. You may use the said surfactant individually or in combination of 2 or more types. Among the above surfactants, anionic surfactants are preferable from the viewpoint of dispersion stability during polymerization.

The aqueous emulsion can be prepared by a known method. For example, an aqueous emulsion can be obtained by adding a vinyl-based monomer to an aqueous medium and dispersing the vinyl-based monomer with a fine emulsifier such as a homogenizer, an ultrasonic treatment machine, and a nanomizer. The vinyl-based monomer may contain a polymerization initiator, if necessary. The polymerization initiator may be previously mixed with the vinyl-based monomer and then dispersed in the aqueous medium, or both may be separately dispersed and mixed in the aqueous medium. The particle diameter of the vinyl monomer droplets in the obtained aqueous emulsion is preferably smaller than that of the seed particles because the vinyl monomer is efficiently absorbed by the seed particles.

The seed particles may be added directly to the aqueous emulsion, or may be added in a form in which the seed particles are dispersed in an aqueous dispersion medium. After adding the seed particles to the aqueous emulsion, the seed particles are allowed to absorb the vinyl-based monomer. This absorption can be usually performed by stirring the aqueous emulsion after the seed particles are added at room temperature (about 20° C.) for 1 to 12 hours. Further, absorption may be promoted by heating the aqueous emulsion to about 30 to 50°C.

The seed particles swell by absorbing the vinyl-based monomer. The mixing ratio of the vinyl monomer and the seed particles is preferably in the range of 5 to 150 parts by weight, and in the range of 10 to 120 parts by weight, with respect to 1 part by weight of the seed particles. More preferably. When the mixing ratio of the vinyl-based monomer to the seed particles becomes small, the increase in particle size due to polymerization becomes small, which may reduce the productivity. When the mixing ratio of the vinyl-based monomer to the seed particles becomes large, the vinyl-based monomer may not be completely absorbed by the seed particles and may be independently suspension-polymerized in an aqueous medium to generate abnormal particles. The end of absorption can be determined by observing the expansion of the particle size by observing with an optical microscope.

A polymerization initiator can be added to the aqueous emulsion as needed. Examples of the polymerization initiator include benzoyl peroxide, lauroyl peroxide, orthochloroperoxybenzoyl, orthomethoxybenzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, t-butylperoxy-2-ethylhexano. , Organic peroxides such as di-t-butyl peroxide, 2,2'-azobisisobutyronitrile, 1,1'-azobiscyclohexanecarbonitrile, 2,2'-azobis(2,4- Examples thereof include azo compounds such as dimethylvaleronitrile). The polymerization initiator is preferably used in the range of 0.1 to 3 parts by weight with respect to 100 parts by weight of the vinyl-based monomer.

Next, the core particles are obtained by polymerizing the vinyl monomer absorbed by the seed particles. The polymerization temperature is appropriately selected according to the type of vinyl monomer and the polymerization initiator. The polymerization temperature is preferably in the range of 25 to 110°C, more preferably 50 to 100°C. The polymerization reaction is preferably carried out at a raised temperature after the seed particles have completely absorbed the monomer and the polymerization initiator. After completion of the polymerization, the core particles are centrifuged to remove the aqueous medium if necessary, washed with water and a solvent, dried and isolated.

In the above polymerization step, a polymer dispersion stabilizer may be added in order to improve the dispersion stability of the core particles. As the polymer dispersion stabilizer, for example, polyvinyl alcohol, polycarboxylic acid, celluloses (hydroxyethyl cellulose, carboxymethyl cellulose, etc.), polyvinyl pyrrolidone, etc. can be used. Further, these polymer dispersion stabilizers may be used in combination with an inorganic water-soluble polymer compound such as sodium tripolyphosphate. Of these, polyvinyl alcohol and polyvinyl pyrrolidone are preferable as the polymer dispersion stabilizer. The addition amount of the polymer dispersion stabilizer is preferably 1 to 10 parts by weight with respect to 100 parts by weight of the vinyl-based monomer.

Further, in order to suppress the generation of emulsified particles in an aqueous system, a water-soluble polymerization inhibitor such as nitrites, sulfites, hydroquinones, ascorbic acids, water-soluble vitamin Bs, citric acid and polyphenols may be used. Good.

〔shell〕
The shell is made of a conductive polymer. The conductive polymer may be a polyaniline-based polymer, a polyisothianaphthene-based polymer, or the like, but a more uniform shell is easily formed, and conductive resin particles having desired conductivity are obtained. Therefore, it is preferably a polymer of at least one monomer selected from the group consisting of nitrogen-containing heteroaromatic compounds and sulfur-containing heteroaromatic compounds.

Examples of the nitrogen-containing heteroaromatic compound include pyrrole, indole, imidazole, pyridine, pyrimidine, pyrazine, and alkyl-substituted products thereof (for example, alkyl groups having 1 to 4 carbon atoms such as methyl group, ethyl group, propyl group, and butyl). Examples include derivatives such as a group-substituted product, a halogen-substituted product (for example, a fluoro-, chloro-, bromo-group-containing halogen group-substituted product), and a nitrile-substituted product. Polymers of pyrrole and derivatives of pyrrole are preferable as the nitrogen-containing heteroaromatic compound because a more uniform shell is easily formed and conductive resin particles having desired conductivity are obtained. Examples of the derivative of pyrrole include 3,4-dimethylpyrrole.

As the sulfur-containing aromatic compound, thiophene and a derivative of thiophene are preferable as the nitrogen-containing aromatic compound because conductive resin particles having desired conductivity can be obtained. Examples of the thiophene derivative include 3,4-ethylenedioxythiophene, 3-methylthiophene, and 3-octylthiophene. These monomers can be used alone to form a homopolymer, or can be used in combination of two or more kinds to form a copolymer.

The thickness of the shell is preferably in the range of 30 to 300 nm, more preferably 50 to 200 nm. When the thickness of the shell is within the above range, sufficient conductivity can be obtained. The fluctuation in the thickness of the shell is preferably 50% or less, and more preferably 40% or less.

[Method of forming shell]
In the conductive resin particles, the conductive polymer forming the shell has at least one monomer selected from the group consisting of a nitrogen-containing heteroaromatic compound and a sulfur-containing heteroaromatic compound (hereinafter, simply referred to as "monomer"). In the case of a polymer of “monomer”), it can be produced by a method of coating the above-mentioned core particles with a polymer of the above-mentioned monomer. As a method for coating the core particles with the polymer of the monomer, the core particles are dispersed in an aqueous medium containing an oxidizing agent to prepare a dispersion liquid (emulsion or suspension), and the dispersion liquid is simply added. A method is preferred in which the monomer is added and stirred, and the surface of the core particle is coated with the polymer of the monomer by oxidative polymerization.

The amount of the above-mentioned monomer added may be set according to the desired conductivity, and is preferably in the range of 1 to 30 parts by weight, and preferably 3 to 20 parts by weight, relative to 100 parts by weight of the core particles. Is more preferable. The amount of the above-mentioned monomer added is 1 part by weight or more with respect to 100 parts by weight of the core particle, and the entire surface of the core particle is uniformly coated with a polymer of the above-mentioned monomer to obtain desired conductivity. Is possible. On the other hand, by setting the addition amount of the monomer to 30 parts by weight or less with respect to 100 parts by weight of the core particles, the added monomer is polymerized by itself, so that particles other than the target conductive resin particles can be obtained. It is possible to prevent it.

(1) Oxidizing agent Examples of the oxidizing agent include inorganic acids such as hydrochloric acid, sulfuric acid and chlorosulfonic acid, organic acids such as alkylbenzenesulfonic acid and alkylnaphthalenesulfonic acid, and metal halogens such as ferric chloride and aluminum chloride. Compounds, halogen acids such as potassium perchlorate, potassium persulfate, ammonium persulfate, sodium persulfate, and peroxides such as hydrogen peroxide. You may use these individually or in mixture. The oxidizing agent is preferably an alkali metal salt of inorganic peracid. Specific examples of the alkali metal salt of inorganic peracid include potassium persulfate and sodium persulfate.

The amount of the oxidizing agent used is preferably 0.5 to 2.0 molar equivalents based on the total amount of the monomers. By setting the amount of the oxidant to be 0.5 molar equivalent or more based on the total amount of the monomer, the entire surface of the core particle is uniformly covered with the shell containing the polymer of the monomer, and the desired conductivity is obtained. It becomes possible to obtain. On the other hand, when the amount of the oxidizing agent used is 2.0 molar equivalents or less based on the total amount of the monomers, the added monomer is polymerized alone, and particles other than the target conductive resin particles can be produced. It is possible to prevent it.

The aqueous medium to which the above-mentioned oxidizing agent is added is not particularly limited as long as it can dissolve or disperse the monomer, but water or water and methanol, ethanol, n-propanol, isopropanol, n- Examples thereof include alcohols such as butanol and t-butanol; ethers such as diethyl ether, isopropyl ether, butyl ether, methyl cellosolve, and tetrahydrofuran; and mixed media with ketones such as acetone, methyl ethyl ketone, and diethyl ketone.

(2) Aqueous medium The aqueous medium to which the oxidizing agent is added preferably has a pH of 3 or more. When the pH is 3 or more, the entire surface of the core particle is uniformly covered with the shell containing the polymer of the monomer, and the desired conductivity can be obtained. For stable coating, it is more preferable to adjust the pH within the range of 3 to 10.

(3) Surfactant A surfactant may be added to the aqueous medium. As the surfactant, any of an anionic surfactant, a cationic surfactant, a zwitterionic surfactant and a nonionic surfactant can be used.

Examples of the anionic surfactant include sodium oleate, fatty acid soap such as castor oil potassium soap, sodium lauryl sulfate, alkyl sulfate ester salt such as ammonium lauryl sulfate, alkylbenzene sulfonate such as sodium dodecylbenzenesulfonate, alkyl Sulfonate, alkyl naphthalene sulfonate, alkane sulfonate, dialkyl sulfosuccinate, alkyl phosphate ester salt, naphthalene sulfonate formalin condensate, polyoxyethylene alkyl phenyl ether sulfate ester salt, polyoxyethylene alkyl sulfate ester salt Etc.

Examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxysorbitan fatty acid ester, polyoxyethylene alkylamine, glycerin fatty acid ester, An oxyethylene-oxypropylene block polymer etc. are mentioned.

Examples of the above-mentioned cationic surfactant include alkylamine salts such as laurylamine acetate and stearylamine acetate, and quaternary ammonium salts such as lauryltrimethylammonium chloride.

Examples of the zwitterionic surfactants include lauryl dimethylamine oxide, phosphoric acid ester-based or phosphorous acid ester-based surfactants, and the like. You may use the said surfactant individually or in combination of 2 or more types. The amount of the surfactant added is preferably in the range of 0.0001 to 1 part by weight with respect to 100 parts by weight of the aqueous medium.

In addition to the surfactant, a polymer dispersion stabilizer may be added to the aqueous medium. Examples of the polymer dispersion stabilizer include polyacrylic acid, copolymers thereof and neutralized products thereof, and polymethacrylic acid, copolymers thereof and neutralized products thereof, polyvinylpyrrolidone, hydroxypropyl cellulose (HPC) and the like. Are listed. The polymer dispersion stabilizer may be used in combination with the above-mentioned surfactant.

(4) Oxidative Polymerization In the method for producing conductive resin particles using oxidative polymerization described above, the core particles are dispersed in an aqueous medium containing an oxidizing agent to prepare a dispersion liquid, and a monomer is added to the dispersion liquid. By conducting oxidative polymerization with stirring, conductive resin particles in which the core particles are coated with a polymer of the above-mentioned monomer are obtained. The temperature of oxidative polymerization is preferably in the range of −20 to 40° C., and the time of oxidative polymerization is preferably in the range of 0.5 to 10 hours.

The emulsion in which the conductive resin particles are dispersed is optionally centrifuged to remove the aqueous medium, washed with water and a solvent, dried, and isolated.

In the above description, as a method of coating the core particle with the polymer, a method of mixing the monomer in an aqueous medium containing the core particle and an oxidizing agent to oxidize and polymerize the monomer has been described. The method of coating the polymer is not limited to this method. For example, a method of coating a core particle with a polymer using a dry method can also be adopted. Examples of the dry method include a method using a ball mill, a method using a V-type mixer, a method using a high-speed fluidized dryer, a method using a hybridizer, and a mechanofusion method.

[Uses of conductive resin particles]
The conductive resin particles of the present invention can be preferably used in applications where the conductive resin particles are brought into close contact with each other to develop conductivity. The conductive resin particle of the present invention is a conductive paste for electrical connection in an electronic circuit board or the like (having conductive particles dispersed in a binder resin), or in an electronic circuit board or the like when applied and dried. Conductive ink capable of forming a conductive film for electrical connection (conductive particles are dispersed in a solution of a binder resin dissolved in a solvent), conductivity of a conductive roller used for a transfer roller, etc. It can be used as an electroconductive particle used in an elastic layer (in which electroconductive particles are dispersed in an elastic body), an anti-blocking agent, or the like.

[Conductive resin composition]
The conductive resin composition of the present invention contains the conductive resin particles of the present invention and a matrix resin. The conductive resin composition of the present invention can be produced by mixing the conductive resin particles of the present invention with a matrix resin.

Examples of the matrix resin include polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polyamide 6, polyamide 66, polyamide 12, ABS resin (acrylonitrile-butadiene-styrene copolymer resin), AS resin (acrylonitrile-styrene copolymer resin), polyethylene, Polypropylene, polyacetal, polyamideimide, polyethersulfone, polyimide, polyphenylene oxide, polyphenylene sulfide, polystyrene, thermoplastic polyurethane elastomer, thermoplastic polyester elastomer, thermoplastic polyamide elastomer, polyvinyl chloride, polyvinylidene fluoride, ethylene tetrafluoroethylene One or a mixture of two or more thermoplastic resins such as a polymer (ETFE resin), a tetrafluoroethylene perfluoroalkyl vinyl ether copolymer (PFA resin) and a polyether ketone can be used. The type of thermoplastic resin used as the matrix resin is the characteristics of the target conductive resin composition (mechanical strength, abrasion resistance, chemical resistance, heat resistance, and molding of a conductive resin composition to form a molded article). It is appropriately selected depending on the formability during production).

The conductive resin particles are preferably added in an amount of 1 to 200 parts by weight with respect to 100 parts by weight of the matrix resin.

Other functional fillers may be appropriately added to the conductive resin composition depending on the function required for the intended molded product. Examples of the functional fillers include reinforcing fibers such as glass fibers and carbon fibers, flame retardants, matting agents, heat stabilizers, light stabilizers, colorants, lubricants and the like.

The conductive resin composition of the present invention is formed into a molded product by mixing (kneading) the matrix resin, the conductive resin particles, and other functional fillers appropriately contained therein and molding the mixture into a desired shape by hot pressing. be able to. Alternatively, the conductive resin composition of the present invention, the matrix resin, the conductive resin particles, and the other appropriately contained functional filler is mixed (kneading) in an appropriately heated state, after molding into pellets, the pellets It can be used as a molded product by extrusion molding, injection molding, or the like. As a result, a molded product having excellent conductivity and antistatic properties can be obtained.

〔Coating agent〕
The coating agent of the present invention contains the conductive resin particles of the present invention and a binder resin.

The binder resin is not particularly limited as long as it is used in the relevant field, depending on the required properties such as transparency, dispersibility of conductive resin particles, light resistance, moisture resistance, and heat resistance. Not something. Examples of the binder resin include (meth)acrylic resin; (meth)acrylic-urethane resin; urethane resin; polyvinyl chloride resin; polyvinylidene chloride resin; melamine resin; styrene resin; alkyd resin. Resin; Phenolic resin; Epoxy resin; Polyester resin; Silicone resin such as alkylpolysiloxane resin; (Meth)acrylic-silicone resin, silicone-alkyd resin, silicone-urethane resin, silicone-polyester resin Examples of the modified silicone resin include fluorine-based resins such as polyvinylidene fluoride and fluoroolefin vinyl ether polymer.

From the viewpoint of improving the durability of the coating agent, the binder resin is preferably a curable resin capable of forming a crosslinked structure by a crosslinking reaction. The curable resin can be cured under various curing conditions. The curable resin is classified into an ultraviolet curable resin, an ionizing radiation curable resin such as an electron beam curable resin, a thermosetting resin, and a warm air curable resin depending on the type of curing.

Examples of the thermosetting resin include thermosetting urethane resin composed of acrylic polyol and isocyanate prepolymer, phenol resin, urea melamine resin, epoxy resin, unsaturated polyester resin, silicone resin and the like.

The ionizing radiation curable resin is synthesized from a polyfunctional alcohol (poly(meth)acrylate resin such as polyhydric alcohol polyfunctional (meth)acrylate); a diisocyanate, a polyhydric alcohol, and a (meth)acrylic acid ester having a hydroxy group. Examples of such polyfunctional urethane acrylate resins include: As the ionizing radiation curable resin, a polyfunctional (meth)acrylate resin is preferable, and a polyhydric alcohol polyfunctional (meth)acrylate having 3 or more (meth)acryloyl groups in one molecule is more preferable. Specific examples of the polyhydric alcohol polyfunctional (meth)acrylate having three or more (meth)acryloyl groups in one molecule include trimethylolpropane tri(meth)acrylate, trimethylolethanetri(meth)acrylate, 1,2,4-Cyclohexane tetra(meth)acrylate, pentaglycerol triacrylate, pentaerythritol tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol triacrylate, dipentaerythritol pentaacrylate, dipentaerythritol tetra (Meth)acrylate, dipentaerythritol hexa(meth)acrylate, tripentaerythritol triacrylate, tripentaerythritol hexaacrylate and the like can be mentioned. Two or more types of the above ionizing radiation curable resins may be used in combination.

Other than these, as the ionizing radiation curable resin, polyether resins, polyester resins, epoxy resins, alkyd resins, spiro acetal resins, polybutadiene resins, polythiol polyene resins and the like having acrylate-based functional groups can also be used.

When an ultraviolet curable resin is used among the above ionizing radiation curable resins, a photopolymerization initiator is added to the ultraviolet curable resin to form a binder resin. Any photopolymerization initiator may be used, but it is preferable to use one that is suitable for the ultraviolet curable resin used.

As the photopolymerization initiator, acetophenones, benzoins, benzophenones, phosphine oxides, ketals, α-hydroxyalkylphenones, α-aminoalkylphenones, anthraquinones, thioxanthones, azo compounds, peroxides (Described in JP 2001-139663 A), 2,3-dialkyldione compounds, disulfide compounds, fluoroamine compounds, aromatic sulfoniums, onium salts, borate salts, active halogen compounds, α-acyl oximes. Examples thereof include esters.

Examples of the acetophenones include acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, 1-hydroxydimethylphenylketone, 1-hydroxycyclohexylphenylketone, 2-methyl-4-methylthio-2-morpholinopropio. Examples include phenone and 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone. Examples of the benzoins include benzoin, benzoin benzoate, benzoin benzene sulfonate, benzoin toluene sulfonate, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and the like. Examples of the benzophenones include benzophenone, 2,4-dichlorobenzophenone, 4,4-dichlorobenzophenone, p-chlorobenzophenone and the like. Examples of the phosphine oxides include 2,4,6-trimethylbenzoyldiphenylphosphine oxide. Examples of the ketals include benzylmethyl ketals such as 2,2-dimethoxy-1,2-diphenylethan-1-one. Examples of the α-hydroxyalkylphenones include 1-hydroxycyclohexyl phenyl ketone. Examples of the α-aminoalkylphenones include 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone.

As a commercially available photo-radical polymerization initiator, a trade name "IRGACURE (registered trademark) 651" (2,2-dimethoxy-1,2-diphenylethane-1-one) manufactured by BASF Japan Ltd., manufactured by BASF Japan Ltd. Trade name "IRGACURE (registered trademark) 184", manufactured by BASF Japan Ltd. "IRGACURE (registered trademark) 907" (2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl )-1-Propanone) etc. are mentioned as a preferable example.

The amount of the photopolymerization initiator used is usually within the range of 0.5 to 20% by weight, and preferably within the range of 1 to 5% by weight, based on 100% by weight of the binder resin.

As the binder resin, a thermoplastic resin can be used in addition to the curable resin. Examples of the thermoplastic resin include cellulose derivatives such as acetyl cellulose, nitrocellulose, acetyl butyl cellulose, ethyl cellulose, and methyl cellulose; vinyl acetate homopolymers and copolymers, vinyl chloride homopolymers and copolymers, and vinylidene chloride. Vinyl-based resins such as homopolymers and copolymers; acetal resins such as polyvinyl formal and polyvinyl butyral; homopolymers and copolymers of acrylic acid esters, homopolymers and copolymers of methacrylic acid esters (meth ) Acrylic resins; polystyrene resins; polyamide resins; linear polyester resins; polycarbonate resins and the like.

The coating agent may further contain water and/or an organic solvent. When applying the coating agent to the substrate film, the organic solvent is not particularly limited as long as it makes it easy to apply the coating agent to the substrate film by including it in the coating agent. Not something. Examples of the organic solvent include aromatic solvents such as toluene and xylene; alcohol solvents such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, and propylene glycol monomethyl ether; Ester solvents such as ethyl acetate and butyl acetate; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone and cyclohexanone; 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, ethylene glycol dimethyl ether, ethylene Glycol ethers such as glycol diethyl ether, diethylene glycol dimethyl ether, and propylene glycol methyl ether; 2-methoxyethyl acetate, 2-ethoxyethyl acetate (cellosolve acetate), 2-butoxyethyl acetate, propylene glycol methyl ether acetate And other glycol ether esters; chlorine-based solvents such as chloroform, dichloromethane, trichloromethane, methylene chloride; ether-based solvents such as tetrahydrofuran, diethyl ether, 1,4-dioxane, 1,3-dioxolane; N-methylpyrrolidone, dimethyl An amide solvent such as formamide, dimethylsulfoxide, dimethylacetamide or the like can be used. These organic solvents may be used alone or in combination of two or more.

〔the film〕
The film of the present invention contains the conductive resin particles of the present invention. The film of the present invention has, for example, a structure obtained by applying a coating agent containing conductive resin particles and a binder resin onto a base film. The film having this structure can be suitably used as a conductive film or an antistatic film.

The base film is preferably transparent. Examples of the transparent substrate film include polyester-based polymers such as polyethylene terephthalate (hereinafter abbreviated as “PET”) and polyethylene naphthalate, cellulose-based polymers such as diacetyl cellulose and triacetyl cellulose (TAC), and polycarbonate-based polymers. , A film made of a polymer such as an acrylic polymer such as polymethylmethacrylate. Further, as the transparent substrate film, polystyrene, styrene-based polymers such as acrylonitrile-styrene copolymer, polyethylene, polypropylene, polyolefin having a cyclic or norbornene structure, olefin-based polymer such as ethylene-propylene copolymer, vinyl chloride-based A film made of a polymer or a polymer such as an amide polymer such as nylon or aromatic polyamide can also be used. Further, as a transparent substrate film, an imide polymer, a sulfone polymer, a polyether sulfone polymer, a polyether ether ketone polymer, a polyphenyl sulfide polymer, a vinyl alcohol polymer, a vinylidene chloride polymer, a vinyl butyral polymer. A film made of a polymer, an arylate-based polymer, a polyoxymethylene-based polymer, an epoxy-based polymer, or a polymer such as a blend of the above polymers can also be used. As the above-mentioned substrate film, one having a particularly small birefringence is preferably used. Further, a film obtained by further providing an easy-adhesion layer on a film made of these polymers can also be used as the base film. The easy-adhesion layer can be formed of a resin such as a (meth)acrylic resin, a copolyester resin, a polyurethane resin, a styrene-maleic acid graft polyester resin, or an acrylic graft polyester resin. In addition, in this specification, "(meth)acryl" shall mean acryl or methacryl.

The thickness of the base film can be appropriately determined, but generally, from the viewpoint of strength, workability such as handling, and thin layer property, it is within a range of 10 to 500 μm and within a range of 20 to 300 μm. Is preferable, and more preferably within the range of 30 to 200 μm.

Moreover, you may add an additive to the said base film. Examples of the additive include an ultraviolet absorber, an infrared absorber, an antistatic agent, a refractive index adjusting agent, and an enhancer.

The method for applying the above coating agent on the base film includes bar coating, blade coating, spin coating, reverse coating, die coating, spray coating, roll coating, gravure coating, micro gravure coating, lip coating and air knife coating. A known coating method such as a dipping method may be used.

When the binder resin contained in the coating agent is an ionizing radiation curable resin, after coating the coating agent, the solvent is dried as necessary, and the ionizing radiation curable resin is cured by irradiating with active energy rays. You can do it.

Examples of the active energy rays include ultraviolet rays emitted from a light source such as a xenon lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, a carbon arc lamp, and a tungsten lamp; Type, resonance transformer type, insulating core transformer type, linear type, dynamitron type, high frequency type electron beam accelerators, α rays, β rays, γ rays and the like can be used.

The thickness of the layer in which the conductive resin particles are dispersed in the binder resin (antiglare layer) formed by coating (and curing) the above coating agent is not particularly limited, and depends on the particle diameter of the conductive resin particles. Although appropriately determined, it is preferably in the range of 1 to 10 μm, more preferably in the range of 3 to 7 μm.

The film of the present invention is not limited to the above-mentioned constitution, and may be a film-shaped product of the same molding resin composition as a coating agent containing conductive resin particles and a binder resin. Good. The film having this structure can be suitably used as a conductive film or an antistatic film.

[Gap material]
The gap material of the present invention contains the conductive resin particles of the present invention. The gap material of the present invention can evenly disperse in-plane spacers for liquid crystal display devices, seal spacers for liquid crystal display devices, EL (electroluminescence) display device spacers, touch panel spacers, and gaps between various substrates such as ceramics and plastics. It is used as a spacer for holding a gap distance such as a gap holding material that can be held. Since the gap material of the present invention contains the conductive resin particles of the present invention having good conductivity, it has conductivity and exhibits an antistatic function.

In the gap material of the present invention, when a uniform gap effect is obtained, the coefficient of variation of the volume-based particle diameter of the conductive resin particles is preferably 20% or less, and more preferably less than 10%. preferable.

Hereinafter, the present invention will be described with reference to Examples and Comparative Examples, but the present invention is not limited thereto. First, a method for measuring the volume average particle diameter, the coefficient of variation of the particle diameter on a volume basis, the 10% compressive strength, and the conductivity of the conductive resin particles in the following Examples and Comparative Examples will be described.

(Measuring method of variation coefficient of volume average particle diameter and volume-based particle diameter of conductive resin particles)
The volume average particle diameter of the conductive resin particles and the coefficient of variation (CV value) of the particle diameter on a volume basis were measured by the Coulter method as follows.

The volume average particle diameter of the conductive resin particles is measured by Coulter Multisizer ^™ 3 (measurement device manufactured by Beckman Coulter, Inc.). The measurement shall be performed using an aperture calibrated according to the Multisizer ^™ 3 User's Manual issued by Beckman Coulter, Inc.

The aperture used for the measurement is appropriately selected depending on the size of the conductive resin particles to be measured. Current (aperture current) and Gain (gain) are appropriately set according to the size of the selected aperture. For example, when an aperture having a size of 50 μm is selected, Current (aperture current) is set to −800 and Gain (gain) is set to 4.

As a sample for measurement, 0.1 g of the conductive resin particles was added to 10 ml of a 0.1 wt% nonionic surfactant aqueous solution, and a touch mixer (“TOUCHMIXER MT-31” manufactured by Yamato Scientific Co., Ltd.) and an ultrasonic cleaner ( "ULTRASONIC CLEANER VS-150" manufactured by Vervoclear Co., Ltd.) is used to make a dispersion liquid. During the measurement, the beaker is gently stirred so that air bubbles do not enter, and the measurement is finished when 100,000 conductive resin particles are measured. The volume average particle diameter of the conductive resin particles is an arithmetic average in a volume-based particle size distribution of 100,000 particles.

The coefficient of variation of the volume-based particle diameter of the conductive resin particles is calculated by the following mathematical formula.
Coefficient of variation in volume-based particle size of conductive resin particles = (standard deviation of volume-based particle size distribution of conductive resin particles
÷ Volume average particle diameter of conductive resin particles) × 100

(Method of measuring 10% compressive strength of conductive resin particles)
The 10% compressive strength (S10 strength) of the resin particles was measured under the following measurement conditions using a micro compression tester “MCTM-200” manufactured by Shimadzu Corporation.

Specifically, a dispersion liquid in which resin particles were dispersed in ethanol was applied to a mirror-finished steel sample stage and dried to prepare a measurement sample. Then, in an environment of room temperature of 20° C. and relative humidity of 65%, one independent fine resin particle (a state in which other resin particles do not exist within a range of at least 100 μm in diameter) is selected and selected by an optical microscope of MCTM-200. The diameter of the resin particles was measured with a particle diameter measuring cursor of MCTM-200. At this time, as the resin particles, resin particles within a range of ±0.5 μm from the volume average particle diameter confirmed by the measuring method by the Coulter method described above were selected. Resin particles outside the range are not used for measuring the compressive strength. Next, the test indenter was dropped at the apex of the selected resin particles at the following load speed to gradually load the resin particles up to a maximum load of 9.81 mN, and the diameter of the resin particles measured previously was 10 The compressive strength was calculated from the load at the time of% displacement by the following formula. The measurement was performed 6 times for each resin particle, and the average value of 4 data excluding the data of the maximum value and the minimum value was taken as the 10% compression strength (S10 strength).

<Calculation formula of compressive strength>
Compressive strength (MPa)=2.8×load (N)/{π×(particle diameter (mm)) ² }
<Condition strength measurement conditions>
Test temperature: Room temperature (20°C) 65% relative humidity
Upper indenter: Flat indenter with a diameter of 50 μm (material: diamond)
Lower pressure plate: SKS flat plate Test type: Compression test (MODE1)
Test load: 9.81mN
Load speed: 0.732mN/sec
Displacement full scale: 20 (μm)

(Method for measuring the conductivity of conductive resin particles)
With "Powder resistance measurement system MCP-PD51 type" (manufactured by Mitsubishi Chemical Analytech Co., Ltd.), a load is applied to the conductive resin particles filled in the probe by a hydraulic pump in increments of 4 kN from 0 to 20 kN. The conductivity was measured for the conductive resin particles under the respective loads (0, 4 kN, 8 kN, 12 kN, 16 kN, and 20 kN). The highest numerical value among the electric conductivity obtained by measuring with each load was defined as the electric conductivity of the conductive resin particles. Regarding the conductive resin particles, the water content was measured in advance by Karl Fischer water measurement, and it was confirmed that the water content was 1.0% by weight or less. As the resistivity meter used in the "powder resistance measurement system MCP-PD51 type", a low resistivity meter "Loresta (registered trademark)-GX MCP-T700" (manufactured by Mitsubishi Chemical Analytech Co., Ltd.) was used.

(Example 1)
[Production of core particles]
[Preparation of aqueous phase]
To a beaker, 200 parts by weight of deionized water as an aqueous medium, 10 parts by weight of magnesium pyrophosphate as a dispersant, and 0.04 part by weight of sodium lauryl sulfate as an anionic surfactant were added, and the aqueous phase was added. Prepared.

[Preparation of oil phase]
In a beaker different from the beaker used for the preparation of the aqueous phase, 60 parts by weight of n-butyl acrylate as a monofunctional (meth)acrylic acid ester monomer, 15 parts by weight of methyl acrylate, 2-ethylhexyl acrylate 10 Parts by weight, and 5 parts by weight of poly(ethylene glycol-propylene glycol) monomethacrylate (“Blenmer (registered trademark) 50PEP-300” manufactured by NOF CORPORATION), and as a monomer represented by the general formula (I). Ethylene glycol dimethacrylate (Kyoeisha Chemical Co., Ltd. "light ester EG") 10 parts by weight, 2,2'-azobis(2,4-dimethylvaleronitrile) 0.2 part by weight and a polymerization initiator. 0.15 parts by weight of benzoyl oxide was added and sufficiently stirred to prepare a mixture that became an oil phase.

[Polymerization reaction]
The prepared oil phase was added to the previously prepared aqueous phase, and the mixture was stirred for 10 minutes at a stirring speed of 5000 rpm using a homomixer (manufactured by Primix Co., Ltd., tabletop type, product name "Homomixer MARKII 2.5 type"), The oil phase was dispersed in the aqueous phase to obtain a dispersion liquid. This dispersion was put into a polymerization reactor equipped with a stirrer, a heating device, and a thermometer, and stirred at 60° C. for 6 hours to carry out a suspension polymerization reaction. Next, the suspension (reaction solution) in the polymerization reactor was cooled to 30° C., and then hydrochloric acid was added to decompose magnesium pyrophosphate. The suspension was then suction filtered. The filtration residue was washed with ion-exchanged water and dehydrated to obtain an intended water-containing cake of core particles made of a polymer of a vinyl monomer.

[Production of conductive resin particles]
[Polymerization reaction]
In a beaker, 25 parts by weight of the obtained water-containing cake of core particles was dispersed in 50 parts by weight of deionized water to obtain a core particle dispersion liquid. Next, 20 parts by weight of potassium persulfate as an oxidizing agent was dissolved in 300 parts by weight of deionized water to prepare an aqueous potassium persulfate solution. The above-prepared core particle dispersion liquid is mixed with the above potassium persulfate aqueous solution and stirred for 30 minutes. To the resulting mixed liquid, 5 parts by weight of pyrrole as a nitrogen-containing aromatic compound was added, and the mixture was stirred at 25° C. for 5 hours to polymerize pyrrole, thereby forming the target polypyrrole as a conductive polymer. Conductive resin particles (core-shell particles) in which core particles were coated with shells were obtained. The obtained conductive resin particles had a volume average particle diameter of 14.8 μm, a coefficient of variation of particle diameter based on volume of 45%, and a 10% compressive strength of 1.4 MPa.

[Conductivity measurement]
The conductivity of the conductive resin particles obtained in the previous step was measured and found to be 2.4×10 ⁻² S/cm.

(Example 2)
[Production of core particles]
In place of 60 parts by weight of n-butyl acrylate, 15 parts by weight of methyl acrylate, and 10 parts by weight of 2-ethylhexyl acrylate, 79 parts by weight of n-butyl acrylate was used and replaced by 10 parts by weight of ethylene glycol dimethacrylate. And 1 part by weight of ethylene glycol dimethacrylate (“light ester EG” manufactured by Kyoeisha Chemical Co., Ltd.) and tetradecaethylene glycol dimethacrylate as a monomer represented by the general formula (II) (manufactured by Kyoeisha Chemical Co., Ltd. 15 parts by weight of "light ester 14EG" was used, the amount of benzoyl peroxide used was changed to 0.3 parts by weight, and the stirring condition when dispersing the oil phase in the aqueous phase was set to "a stirring speed of 3500 rpm for 5 minutes. Except that the content was changed to "." The target water-containing cake of core particles was obtained in the same manner as in Example 1.

[Production of conductive resin particles]
Except that the hydrous cake of core particles obtained in the previous step was used instead of the core particles of Example 1 and the amount of deionized water used in obtaining the core particle dispersion was changed to 25 parts by weight. In the same manner as in Example 1, the target conductive resin particles were obtained. The obtained conductive resin particles had a volume average particle size of 15.4 μm, a volume-based particle size variation coefficient of 39%, and a 10% compressive strength of 2.3 MPa.

[Conductivity measurement]
The conductivity of the conductive resin particles obtained in the previous step was measured and found to be 2.8×10 ⁻² S/cm.

(Example 3)
[Production of core particles]
In the same manner as in Example 1, a desired water-containing cake of core particles was obtained.

[Production of conductive resin particles]
In the same manner as in Example 1, except that 3,4-ethylenedioxythiophene was used instead of pyrrole and the stirring time during polymerization was changed to 24 hours, the desired polyelectrolyte as a conductive polymer was used. Conductive resin particles in which the core particles were covered with a shell made of (3,4-ethylenedioxythiophene) were obtained. The obtained conductive resin particles had a volume average particle diameter of 16.2 μm, a volume-based particle diameter variation coefficient of 46%, and a 10% compressive strength of 2.5 MPa.

[Conductivity measurement]
The conductivity of the conductive resin particles obtained in the previous step was measured and found to be 1.8×10 ⁻² S/cm.

(Example 4)
[Production of core particles]
[Soap-free polymerization]
In a beaker, 15 parts by weight of methyl methacrylate as a monofunctional (meth)acrylic acid ester monomer was mixed with 0.2 parts by weight of n-octyl mercaptan as a molecular weight modifier to prepare an oil phase.

In a beaker different from the one described above, 0.1 parts by weight of potassium persulfate as a polymerization initiator was dissolved in 80 parts by weight of ion-exchanged water to prepare an aqueous potassium persulfate solution, and the potassium persulfate aqueous solution was mixed with the above oil. The phases were mixed and soap-free polymerization was carried out at 55° C. for 12 hours. As a result, a dispersion liquid containing seed particles made of polymethylmethacrylate was obtained. The volume average particle diameter of the obtained seed particles was 0.51 μm.

[Seed polymerization]
Next, in a new beaker, 70 parts by weight of n-butyl acrylate as a monofunctional (meth)acrylic acid ester monomer, 5 parts by weight of methyl acrylate, 5 parts by weight of 2-ethylhexyl acrylate, and poly(ethylene 5 parts by weight of glycol-propylene glycol) monomethacrylate (“Blenmer (registered trademark) 50PEP-300” manufactured by NOF CORPORATION) and 10 parts by weight of ethylene glycol dimethacrylate as a monomer represented by the general formula (I). And 0.01 part by weight of 2,2′-azobis(2-methylbutyronitrile) as a polymerization initiator. The obtained mixture was mixed with 80 parts by weight of ion-exchanged water as an aqueous medium and 0.08 part by weight of sodium di(2-ethylhexyl)sulfosuccinate as an anionic surfactant to obtain an aqueous solution, An emulsion was obtained by treating with a homomixer (manufactured by PRIMIX Corporation, tabletop type, product name “Homomixer MARKII 2.5 type”) at a stirring speed of 8000 rpm for 10 minutes.

To this emulsion, 40 parts by weight of a dispersion liquid containing seed particles obtained by the above soap-free polymerization was added with stirring. After stirring for 3 hours, 240 parts by weight of ion-exchanged water in which 0.03 parts by weight of polyvinyl alcohol as a polymer dispersion stabilizer was dissolved was added and polymerized while stirring at 60° C. for 6 hours to obtain a polymer emulsion. Was dehydrated by suction filtration, and the residue was washed with ion-exchanged water to obtain a hydrous cake of core particles having a sharp particle size distribution. The volume average particle diameter of the obtained core particles was 1.2 μm.

[Production of conductive resin particles]
The water-containing cake of core particles obtained in the previous step was used instead of the core particles of Example 1, and the amount of deionized water used when the core particles were dispersed to obtain a core particle dispersion was 25% by weight. Target conductive resin particles were obtained in the same manner as in Example 1 except that the parts were changed. The obtained conductive resin particles had a volume average particle diameter of 1.3 μm, a volume-based particle diameter variation coefficient of 9%, and a 10% compression strength of 1.4 MPa.

[Conductivity measurement]
The conductivity of the conductive resin particles obtained in the previous step was measured and found to be 1.5×10 ⁻² S/cm.

(Example 5)
[Production of core particles]
Except that the amount of sodium lauryl sulfate used was changed to 0.005 parts by weight and the stirring when dispersing the oil phase in the aqueous phase was changed to 10 minutes at a stirring speed of 200 rpm without using a homomixer, In the same manner as in Example 1, a desired water-containing cake of core particles was obtained.

[Production of conductive resin particles]
Target conductive resin particles were obtained in the same manner as in Example 1 except that the water-containing cake of core particles obtained in the previous step was used instead of the core particles in Example 1. The obtained conductive resin particles had a volume average particle size of 198 μm, a volume-based particle size variation coefficient of 49%, and a 10% compressive strength of 1.7 MPa.

[Conductivity measurement]
The conductivity of the conductive resin particles obtained in the previous step was measured and found to be 2.0×10 ⁻² S/cm.

(Example 6)
[Production of core particles]
60 parts by weight of n-butyl acrylate, 15 parts by weight of methyl acrylate, and 10 parts by weight of 2-ethylhexyl acrylate were replaced with 45 parts by weight of n-butyl acrylate and replaced with 10 parts by weight of ethylene glycol dimethacrylate. Of the target core particles in the same manner as in Example 1 except that 50 parts by weight of a urethane acrylate oligomer (product name “New Frontier (registered trademark) RST-402”, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was used. A wet cake was obtained.

[Production of conductive resin particles]
The water-containing cake of core particles obtained in the previous step was used instead of the core particles of Example 1, and the amount of deionized water used when the core particles were dispersed to obtain a core particle dispersion was 25% by weight. Target conductive resin particles were obtained in the same manner as in Example 1 except that the parts were changed. The obtained conductive resin particles had a volume average particle diameter of 16.2 μm, a volume-based particle diameter variation coefficient of 44%, and a 10% compressive strength of 1.2 MPa.

[Conductivity measurement]
When the conductivity of the conductive resin particles obtained in the previous step was measured, it was 2.6×10 ⁻² S/cm.

(Example 7)
[Production of core particles]
In the same manner as in Example 1, a desired water-containing cake of core particles was obtained.

[Production of conductive resin particles]
The core particles obtained in the previous step were used instead of the core particles of Example 3, and the amount of deionized water used when the core particles were dispersed to obtain a core particle dispersion was changed to 50 parts by weight. Except for the above, the target conductive resin particles were obtained in the same manner as in Example 3. The obtained conductive resin particles had a volume average particle diameter of 16.5 μm, a volume-based particle diameter variation coefficient of 42%, and a 10% compressive strength of 1.2 MPa.

[Conductivity measurement]
The conductivity of the conductive resin particles obtained in the previous step was measured and found to be 2.9×10 ⁻² S/cm.

(Comparative Example 1)
[Production of core particles]
As a monofunctional (meth)acrylic acid ester monomer, n-butyl acrylate 60 parts by weight, methyl acrylate 15 parts by weight, 2-ethylhexyl acrylate 10 parts by weight, and poly(ethylene glycol-propylene glycol) monomethacrylate 5 Core particles were obtained in the same manner as in Example 1 except that 95 parts by weight of methyl methacrylate was used instead of parts by weight and the amount of ethylene glycol dimethacrylate was changed to 5 parts by weight.

[Production of conductive resin particles]
Conductive resin particles were obtained in the same manner as in Example 1 except that 25 parts by weight of isopropyl alcohol was used as the dispersion medium used when obtaining the core particle dispersion liquid instead of 50 parts by weight of deionized water. The 10% compressive strength of the obtained conductive resin particles was 34.3 MPa.

[Conductivity measurement]
The conductivity of the conductive resin particles obtained in the previous step was measured and found to be 2.2×10 ⁻³ S/cm.

(Comparative example 2)
Conductive resin particles were obtained in the same manner as in Comparative Example 1 except that 3,4-ethylenedioxythiophene was used instead of pyrrole, and the stirring time during polymerization was changed to 24 hours. The 10% compressive strength of the obtained conductive resin particles was 36.4 MPa.
[Conductivity measurement]
The conductivity of the conductive resin particles obtained in the previous step was measured and found to be 2.2×10 ⁻³ S/cm.

(Comparative example 3)
[Production of core particles]
In the seed polymerization, 70 parts by weight of n-butyl acrylate, 5 parts by weight of methyl acrylate, 5 parts by weight of 2-ethylhexyl acrylate, and poly(ethylene glycol-propylene glycol) monomethacrylate (“Blenmer (manufactured by NOF CORPORATION) (Registered trademark) 50 PEP-300") 5 parts by weight were replaced with 70 parts by weight of methyl methacrylate, and the amount of ethylene glycol dimethacrylate was changed to 30 parts by weight in the same manner as in Example 4. Core particles were obtained. The volume average particle diameter of the obtained core particles was 1.1 μm.

[Production of conductive resin particles]
The target conductive resin particles were obtained in the same manner as in Example 4 except that the core particles obtained in the previous step were used in place of the core particles of Example 4. The obtained conductive resin particles had a volume average particle diameter of 1.2 μm, a volume-based particle diameter variation coefficient of 9%, and a 10% compressive strength of 36.1 MPa.

[Conductivity measurement]
The conductivity of the conductive resin particles obtained in the previous step was measured and found to be 3.5×10 ⁻³ S/cm.

The volume average particle diameter of the conductive resin particles obtained in Examples 1 to 7 and Comparative Examples 1 to 3, the coefficient of variation of the volume-based particle diameter, 10% compressive strength, and the electrical conductivity are used for the production of the core particles. The composition of the prepared monomer mixture (the composition of the monomer mixture used for seed polymerization in Example 4 and Comparative Example 3) and the type of the monomer used for forming the shell are collectively shown in Table 1. In Table 1, n-butyl acrylate is "BA", methyl acrylate is "MA", 2-ethylhexyl acrylate is "2EHA", methyl methacrylate is "MMA", poly(ethylene glycol-propylene glycol). ) Monomethacrylate "Blenmer (registered trademark) 50PEP-300") is "50PEP-300", ethylene glycol dimethacrylate is "EGDMA", tetradecaethylene glycol dimethacrylate is "14EG", and urethane acrylate "New Frontier (registered trademark)". "RST-402" is abbreviated as "RST-402".

As described above, the conductive resin particles of Examples 1 to 7 have a 10% compressive strength of 0.1 to 30 MPa (1.2 to 2.5 MPa), and thus a 10% compressive strength of more than 30 MPa (34. Excellent conductivity (1. ^{3 to} 36.4 MPa) as compared with the conductivity (2.2 to 3.5×10 ⁻³ S/cm) of the conductive resin particles of Comparative Examples 1 to 3 which is 1.3 to 36.4 MPa. 5 to 2.9×10 ⁻² S/cm).

(Example 8)
An example was applied to a binder solution prepared by dissolving 10 parts by weight of an acrylic resin (manufactured by Mitsubishi Chemical Co., Ltd., trade name "Dianal (registered trademark) BR-106") as a binder resin in 50 parts by weight of toluene as an organic solvent. 10 parts by weight of the conductive resin particles obtained in 1 were mixed and uniformly dispersed to prepare a coating agent.

This coating agent was applied to a PET film having a thickness of 100 μm as a base film using a 30 μm applicator to form a coating film. The coating film on the PET film was allowed to stand for 2 hours in a high temperature bath at 70° C. to obtain a conductive film.

The present invention can be embodied in various other forms without departing from the spirit or the main features thereof. Therefore, the above embodiments are merely examples in all respects, and should not be limitedly interpreted. The scope of the present invention is defined by the scope of the claims, and is not bound by the text of the specification. Further, all modifications and changes belonging to the equivalent range of the claims are within the scope of the present invention.

Further, this application claims the priority right based on Japanese Patent Application No. 2016-194260 filed in Japan on September 30, 2016. By reference to this, the entire contents of which are incorporated into the present application.

Claims (12)

Core particles made of a polymer,
A conductive resin particle having a shell made of a conductive polymer coating the core particle,
The compressive strength at 10% compression deformation is 0.1 to 30 MPa,
The polymer is a monofunctional (meth)acrylic acid ester monomer,
The following general formula (I)

(Wherein, R ₁ is hydrogen or a methyl group, and n is an integer of 1 to 4), and a polymer of a monomer mixture containing the monomer is included. Resin particles. The conductive resin particles according to claim 1,
The monomer mixture has the following general formula (II)

(In formula, R< ₂ > is hydrogen or a methyl group, m is an integer of 5-15.) The electroconductive resin particle further characterized by the above-mentioned. Core particles made of a polymer,
Have a shell made of a conductive polymer covering the core particles,
The shell is a conductive resin particles that are not fibrous ,
The compressive strength at 10% compression deformation is 0.1 to 30 MPa,
A conductive resin particle having a volume-based particle diameter variation coefficient of 9% or more. Core particles made of a polymer,
A conductive resin particle having a shell made of a conductive polymer coating the core particle,
The compressive strength at 10% compression deformation is 0.1 to 30 MPa,
The coefficient of variation of volume-based particle diameter is 9% or more,
The conductive polymer is a polymer of at least one monomer selected from the group consisting of nitrogen-containing heteroaromatic compounds and sulfur-containing heteroaromatic compounds,
The amount of the monomer added is in the range of 1 to 30 parts by weight with respect to 100 parts by weight of the core particles,
Conductive resin particles, wherein the entire surface of the core particles is covered with the conductive polymer. The conductive resin particles according to any one of claims 1 to 5 ,
Conductive resin particles, wherein the conductive polymer is a polymer of at least one monomer selected from the group consisting of nitrogen-containing heteroaromatic compounds and sulfur-containing heteroaromatic compounds. The conductive resin particles according to any one of claims 1 to 5 ,
Conductive resin particles having a volume average particle diameter of 1 to 200 μm. The conductive resin particles according to any one of claims 1 to 7 ,
A conductive resin particle having a volume-based particle diameter variation coefficient of 10% or more. The conductive resin particles according to any one of claims 1 to 8 ,
The conductive resin particles are characterized in that the thickness fluctuation of the shell is 50% or less. Claims and conductive resin particles of any one of 1-8, a conductive resin composition which comprises a matrix resin. Coating agent characterized the conductive resin particles according, to include a binder resin to any one of claims 1-8. Film characterized in that it comprises an electrically conductive resin particles according to any one of claims 1-8. Gap material, characterized in that it comprises an electrically conductive resin particles according to any one of claims 1-8.