JP5241551B2 - Electromagnetic shielding gasket - Google Patents

Description

  The present invention relates to an electromagnetic shielding gasket.

  As an electromagnetic shielding gasket that can be used in a gap between casings of electronic devices, for example, a metal plating layer formed on one surface of a skin layer formed on the surface of a continuous foamed sponge by a physical method such as sputtering or vacuum deposition It has been proposed for a plating sheet having (Patent Document 1). Moreover, even if the continuous foamed sponge is elastically deformed in the vertical direction, the plating layer is provided with a suppression layer so that the plating layer is not broken, that is, cracked on the plating surface.

  In addition, as another electromagnetic shielding gasket, a core material such as a flame retardant urethane sponge coated with a flame retardant plastic film substrate having a metal vapor deposition layer formed on one side or both sides has been proposed ( Patent Document 2).

JP 2002-260449 A JP 2008-078368 A

  However, the electromagnetic wave shielding gasket of Document 1 includes a suppression layer so that the plated layer is not broken even if the continuous foamed sponge is elastically deformed in the vertical direction, that is, the plated surface is not cracked. Since the metal plating layer formed by the method is in a state of being exposed to the outside, it is insufficient to prevent cracking. As a result, when the gasket is bent, the metal plating layer is broken and the electromagnetic shielding Performance will be degraded. Moreover, when it contacts with a housing | casing, a metal plating layer will peel off. Furthermore, there is a problem that the metal plating layer is easily corroded.

  Further, the electromagnetic wave shielding gasket of Document 2 has a problem similar to that of Document 1 because the metal plating layer formed by a physical method is exposed to the outside.

  Therefore, the present invention is that the metal plating layer does not corrode, and even if bent, the metal plating layer is not easily broken, i.e., excellent in bending resistance, and further, for example, when coming into contact with the housing, the metal plating layer is difficult to peel off, That is, an object of the present invention is to provide an electromagnetic shielding gasket having excellent wear resistance.

In the electromagnetic shielding gasket according to claim 1 of the present invention, a coating layer containing conductive polymer particles and a binder is formed on the surface of a substrate, and the metal plating film is electroless plated on the coating layer. A sheet-like elastic body is formed on the metal plating film, and the sheet- like elastic body is a polyurethane urea foam sheet . The electromagnetic wave shielding gasket according to claim 2, wherein the binder is present in an amount of 0.1 to 10 parts by mass with respect to 1 part by mass of the conductive polymer fine particles, and the thickness of the coating layer is 20 Or 500 nm. The electromagnetic wave shielding gasket according to claim 3 is characterized in that the sheet-like elastic body is formed by coating a raw material of the sheet-like elastic body onto the metal plating film.

The gasket for electromagnetic wave shielding of the present invention does not corrode the metal plating layer and is excellent in bending resistance and wear resistance.
Moreover, the electroless plating method in the present invention can form a metal plating film that is excellent in adhesion and thin and smooth on the surface without etching the substrate. As a result, it is possible to obtain an electromagnetic wave shielding gasket in which the surface of the sheet-like elastic body formed on the metal plating film is also excellent in smoothness.

The present invention will be described in more detail.
In the electromagnetic wave shielding gasket of the present invention, a coating layer containing conductive polymer particles and a binder is formed on the surface of a substrate, and a metal plating film is formed on the coating layer by an electroless plating method, A sheet-like elastic body is formed on the metal plating film, and the sheet-like elastic body is an electromagnetic wave shielding gasket which is a polyurethane urea foam sheet .

  The substrate used in the present invention is not particularly limited. For example, polyester resin such as polyethylene terephthalate, acrylic resin such as polymethyl methacrylate, polypropylene resin, polycarbonate resin, polystyrene resin, polyvinyl chloride resin, polyamide resin, polyimide resin. A soft film made of a synthetic resin such as

The coating layer containing the conductive polymer fine particles and the binder of the present invention forms a coating layer by applying a base coating material containing the reducing polymer fine particles and the synthetic resin, or contains the conductive polymer fine particles and the binder. A base coating is applied, and the conductive polymer fine particles are dedoped to form a coating layer. That is, the coating layer before electroless plating needs to be in a state containing reducing polymer fine particles and a binder, and when a base coating containing conductive polymer fine particles and a binder is applied, It is necessary to de-dope the conductive polymer fine particles so as to contain reducing fine polymer particles and a binder. For example, a catalytic metal such as palladium is reduced and adsorbed on a coating layer containing reducible polymer fine particles, and a metal plating film is formed on the coating layer on which the catalytic metal such as palladium is adsorbed. In this case, the reduction of the catalytic metal such as palladium and the adsorption to the polymer fine particles are considered to be in the state shown in the following figure in the case of polypyrrole, for example.
That is, the reducing polymer fine particles (polypyrrole) reduce palladium ions to adsorb palladium (metal) on the polymer fine particles, whereby the polymer fine particles (polypyrrole) are ionized. And doped with palladium, and as a result, develops conductivity. Therefore, the coating film layer of the plated product of the present invention obtained by providing a metal film on the coating film layer by electroless plating method results in a coating film layer containing conductive polymer fine particles and a binder. .

  The reducing polymer fine particle used in the base coating material containing the reducing polymer fine particle and the binder is not particularly limited as long as it is a polymer having a π-conjugated double bond having a conductivity of less than 0.01 S / cm. Examples thereof include polyacetylene, polyacene, polyparaphenylene, polyparaphenylene vinylene, polypyrrole, polyaniline, polythiophene and various derivatives thereof, and preferably polypyrrole. Further, the reducing polymer fine particles are preferably 0.01 S / cm or less, more preferably polymer fine particles having a conductivity of 0.005 S / cm or less. The reducing polymer fine particles can be synthesized and used from a monomer having a π-conjugated double bond, but commercially available reducing polymer fine particles can also be used.

  The conductive polymer fine particles used in the base coating material containing the conductive polymer fine particles and the binder resin are not particularly limited as long as the polymer has a conductive π-conjugated double bond, for example, polyacetylene, Examples include polyacene, polyparaphenylene, polyparaphenylene vinylene, polypyrrole, polyaniline, polythiophene, and various derivatives thereof, and polypyrrole is preferable. The conductive polymer fine particles can be synthesized and used from a monomer having a π-conjugated double bond, but commercially available conductive polymer fine particles can also be used.

  Examples of the binder used for the base coating containing the reducing polymer fine particles and the binder and the base coating containing the conductive polymer fine particles and the synthetic resin include chlorinated polyolefins such as polyvinyl chloride and polypropylene chloride, polycarbonate, polystyrene, Methyl methacrylate, polyester, polysulfone, polyphenylene oxide, polybutadiene, poly (N-vinylcarbazole), carboxylic acid group-containing resin, hydrocarbon resin, ketone resin, phenoxy resin, polyamide, ethyl cellulose, vinyl acetate, ABS resin, polyurethane resin, melamine Resins, unsaturated polyester resins, alkyd resins, epoxy resins, silicon resins and the like can be mentioned.

  The mass ratio of the conductive polymer fine particles and the binder in the coating layer of the present invention is preferably in the range of 1: 0.1 to 1:10. When the ratio of the binder is lower than 1: 0.1 in the mass ratio, the adhesion to the substrate is lowered, so that the bending resistance and the wear resistance are lowered, and the electromagnetic wave shielding property tends to be lowered. . When the ratio of the binder is higher than 1:10, the deposition property of the metal plating film is lowered, so that the electromagnetic wave shielding property tends to be lowered. In addition, although it is said that the electromagnetic wave shielding gasket only needs to have an electromagnetic wave shielding property of 40 dB or more, it is desired that it is 60 dB or more.

  The base paint may contain a solvent in addition to the conductive or reducing polymer fine particles and the binder. The solvent that can be contained in the base paint is not particularly limited as long as it can dissolve the binder, but those that can dissolve the substrate greatly are not preferable. However, it is possible to use a solvent that greatly dissolves the base material by reducing the solubility by mixing it with another low-solubility solvent. Examples of the solvent that can be included in the base paint include aliphatic esters such as butyl acetate, aromatic solvents such as toluene, ketones such as methyl ethyl ketone, cyclic saturated hydrocarbons such as cyclohexane, and chain forms such as n-octane. Examples thereof include saturated hydrocarbons, chain saturated alcohols such as methanol, ethanol and n-octanol, aromatic esters such as methyl benzoate, aliphatic ethers such as diethyl ether, and mixtures thereof. In addition, when using the dispersion liquid previously disperse | distributed to the organic solvent as electroconductive or reducible polymer fine particles, the organic solvent currently used for the dispersion liquid is used as a part or all of the solvent of a base coating material. be able to.

Further, the base coating material can be added with a filler such as a dispersion stabilizer, a thickening agent, a pigment, a dye, an inorganic substance, or the like according to the application, application object or the like.

  The method for applying the base coating onto the substrate of the present invention is not particularly limited. For example, spray, screen printer, gravure printer, flexographic printer, inkjet printer, offset printer, dipping, spin coater, Printing or coating can be performed using a roll coater, a flow coater, or the like. The drying conditions are not particularly limited, and the drying can be performed at room temperature or under heating conditions.

  The thickness of the coating layer to be formed is preferably in the range of 20 to 500 nm. When the thickness of the coating layer is thinner than 20 nm, the deposition property of the metal plating film is lowered, and therefore the electromagnetic wave shielding property tends to be lowered. Moreover, since the adhesiveness with a base material will fall when the film thickness of a coating layer becomes thicker than 500 nm, it exists in the tendency for bending resistance and abrasion resistance to fall, and for electromagnetic wave shielding to fall.

  The coating layer formed using the conductive polymer fine particles is subjected to a dedoping process in order to make the fine particles reducible. As the dedoping treatment, a reducing agent, for example, a borohydride compound such as sodium borohydride or potassium borohydride, an alkylamine borane such as dimethylamine borane, diethylamine borane, trimethylamine borane, triethylamine borane, hydrazine, etc. The method of processing and reducing with the solution to contain, or the method of processing with an alkaline solution is mentioned.

  It is preferable to treat with an alkaline solution from the viewpoint of operability and economy. The layer formed using the conductive polymer fine particles can be dedoped by mild alkali treatment under mild conditions. For example, it is treated in a 1M aqueous sodium hydroxide solution at a temperature of 20 to 50 ° C., preferably 30 to 40 ° C., for 1 to 30 minutes, preferably 3 to 10 minutes. By the above-described dedoping treatment, the polymer fine particles in the coating layer formed using the conductive polymer fine particles are reduced to become reducible polymer fine particles.

  The base material on which the coating layer containing the reducing fine polymer particles produced as described above is formed into a plated product by the electroless plating method. The electroless plating method is a generally known method. Can be done according to. That is, after immersing the base material in a catalyst solution for attaching a catalytic metal such as palladium chloride, the substrate can be washed with water and immersed in an electroless plating bath to obtain a plated product.

  The catalyst solution is a solution containing a noble metal (catalyst metal) having catalytic activity for electroless plating. Examples of the catalyst metal include palladium, gold, platinum, rhodium, etc. These metals may be simple substances or compounds. A palladium compound is preferable from the viewpoint of stability including a metal, and palladium chloride is particularly preferable among them. A preferred specific catalyst solution includes 0.05% palladium chloride-0.005% hydrochloric acid aqueous solution (pH 3). The treatment temperature is 20 to 50 ° C., preferably 30 to 40 ° C., and the treatment time is 0.1 to 20 minutes, preferably 1 to 10 minutes. By the above operation, the reducing polymer fine particles in the coating film become conductive polymer fine particles as a result.

  The base material treated as described above is immersed in a plating solution for depositing metal, thereby forming an electroless plating film. The plating solution is not particularly limited as long as it is a plating solution usually used for electroless plating. That is, metals that can be used for electroless plating, copper, gold, silver, nickel, etc. can all be applied, but copper is preferred. Specific examples of the electroless copper plating bath include, for example, an ATS add copper IW bath (Okuno Pharmaceutical Co., Ltd.). The treatment temperature is 20 to 50 ° C., preferably 30 to 40 ° C., and the treatment time is 1 to 30 minutes, preferably 5 to 15 minutes. The obtained plated product is preferably cured for several hours or more, for example, 2 hours or more, at a temperature lower than the melting point of the binder in the used coating layer. By the above method, a plated product on which a metal plating film that is thin, excellent in smoothness, and excellent in adhesiveness is formed can be produced without performing a complicated etching process or the like.

As the sheet-like elastic body of the present invention,
α) Excellent adhesion and followability with metal plating film,
β) For example, even when the electromagnetic shielding gasket of the present invention is in contact with the casing, the metal plating film can be protected so as not to be peeled off, that is, excellent in wear resistance,
[gamma]) Any sheet-like elastic body that can prevent corrosion of the metal plating film may be used. Here, the above α) will be described. For example, when the gasket for electromagnetic wave shielding is bent, if the adhesion and followability between the sheet-like elastic body and the metal plating film are good, the metal plating film is difficult to break. . Therefore, the sheet-like elastic body of the present invention is required to be a sheet-like elastic body having excellent adhesion and followability, that is, excellent bending resistance.

  As the sheet-like elastic body of the present invention, polyurethane urea foam sheets such as those described in JP-A-11-60768 and JP-A-2003-277459 are flex resistance, wear resistance, strength, cold resistance, It is used because it is excellent in hydrolysis resistance and manufacturing processability.

  The method for forming the sheet-like elastic body on the plated article of the present invention may be performed, for example, by coating a raw material of the sheet-like elastic body on the plated article and under desired drying conditions.

  The thickness of the sheet-like elastic body is preferably in the range of 0.2 to 1.0 mm.

  Below, the specific method for manufacturing the electroconductive or reducing polymer fine particle which can be used for the said base coating material is described.

(1) Production Method of Reducing Polymer Fine Particles Reducing polymer fine particles are contained in an O / W type emulsion obtained by mixing and stirring an organic solvent, water, an anionic surfactant and a nonionic surfactant. , A monomer having a π-conjugated double bond is added, and the monomer can be produced by oxidative polymerization.

  The monomer having a π-conjugated double bond is not particularly limited as long as it is a monomer used for producing a reducing polymer, and examples thereof include pyrrole, N-methylpyrrole, N-ethylpyrrole, and N-phenyl. Pyrrole, N-naphthylpyrrole, N-methyl-3-methylpyrrole, N-methyl-3-ethylpyrrole, N-phenyl-3-methylpyrrole, N-phenyl-3-ethylpyrrole, 3-methylpyrrole, 3- Ethyl pyrrole, 3-n-butyl pyrrole, 3-methoxy pyrrole, 3-ethoxy pyrrole, 3-n-propoxy pyrrole, 3-n-butoxy pyrrole, 3-phenyl pyrrole, 3-toluyl pyrrole, 3-naphthyl pyrrole, 3 -Phenoxypyrrole, 3-methylphenoxypyrrole, 3-aminopyrrole, 3-dimethyla Pyrrole derivatives such as nopyrrole, 3-diethylaminopyrrole, 3-diphenylaminopyrrole, 3-methylphenylaminopyrrole and 3-phenylnaphthylaminopyrrole, aniline, o-chloroaniline, m-chloroaniline, p-chloroaniline, o- Aniline derivatives such as methoxyaniline, m-methoxyaniline, p-methoxyaniline, o-ethoxyaniline, m-ethoxyaniline, p-ethoxyaniline, o-methylaniline, m-methylaniline and p-methylaniline, thiophene, 3 -Methylthiophene, 3-n-butylthiophene, 3-n-pentylthiophene, 3-n-hexylthiophene, 3-n-heptylthiophene, 3-n-octylthiophene, 3-n-nonylthiophene, 3-n- Decylthiophene, Examples include thiophene derivatives such as 3-n-undecylthiophene, 3-n-dodecylthiophene, 3-methoxythiophene, 3-naphthoxythiophene and 3,4-ethylenedioxythiophene, preferably pyrrole, aniline, thiophene And 3,4-ethylenedioxythiophene and the like, more preferably pyrrole.

  Various anionic surfactants used in the production can be used, but those having a plurality of hydrophobic ends (for example, those having a branched structure in a hydrophobic group or those having a plurality of hydrophobic groups) are preferred. . By using such an anionic surfactant having a plurality of hydrophobic ends, stable micelles can be formed, and separation between the aqueous phase and the organic solvent phase is smooth after the polymerization. Reducible polymer fine particles dispersed in are easily available. Among anionic surfactants having multiple hydrophobic ends, di-2-ethylhexyl sodium sulfosuccinate (4 hydrophobic ends), di-2-ethyloctyl sodium sulfosuccinate (4 hydrophobic ends) and branched type Alkyl benzene sulfonate (two hydrophobic ends) can be preferably used.

  The amount of the anionic surfactant in the reaction system is preferably less than 0.05 mol, more preferably 0.005 mol to 0.03 mol, with respect to 1 mol of the monomer having a π-conjugated double bond. When the amount is 0.05 mol or more, the added anionic surfactant acts as a dopant, and the resulting fine particles exhibit conductivity. Therefore, in order to perform electroless plating using this, a dedoping step is required.

  Nonionic surfactants include, for example, polyoxyethylene alkyl ethers, alkyl glucosides, glycerin fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbidic fatty acid esters, polyoxyethylene fatty acid esters, fatty acid alkanolamides, poly Examples include oxyethylene alkylphenyl ethers. These may be used alone or in combination. In particular, those that stably form an O / W emulsion are preferred.

  The amount of the nonionic surfactant in the reaction system is preferably 0.2 mol or less, more preferably 0.2 mol or less with respect to 1 mol of the monomer having a π-conjugated double bond, in addition to the anionic surfactant. It is 05-0.15 mol. If the amount is less than 0.05 mol, the yield and dispersion stability are reduced. On the other hand, if the amount is 0.2 mol or more, it is difficult to separate the aqueous phase from the organic solvent phase after polymerization. It is not preferable because it becomes impossible to obtain.

  In the production, the organic solvent forming the organic phase of the emulsion is preferably hydrophobic. Among these, toluene and xylene, which are aromatic organic solvents, are preferable from the viewpoint of the stability of the O / W emulsion and the affinity with the monomer having a π-conjugated double bond. Although the amphoteric solvent can polymerize a monomer having a π-conjugated double bond, it is difficult to separate the organic phase and the aqueous phase when the produced reducing polymer fine particles are recovered.

  The ratio of the organic phase to the aqueous phase in the emulsion is preferably 75% by volume or more in the aqueous phase. When the water phase is 20% by volume or less, the amount of the monomer having a π-conjugated double bond is reduced, and the production efficiency is deteriorated.

  Examples of the oxidizing agent used in the production include inorganic acids such as sulfuric acid, hydrochloric acid, nitric acid and chlorosulfonic acid, organic acids such as alkylbenzenesulfonic acid and alkylnaphthalenesulfonic acid, potassium persulfate, ammonium persulfate and peroxidation. Peroxides such as hydrogen can be used. These may be used alone or in combination of two or more. Even a Lewis acid such as ferric chloride can polymerize a monomer having a π-conjugated double bond, but the produced particles may aggregate and be unable to be finely dispersed. Particularly preferred oxidizing agents are persulfates such as ammonium persulfate.

  The amount of the oxidizing agent in the reaction system is preferably 0.1 mol or more and 0.8 mol or less, more preferably 0.2 to 0.6 mol with respect to 1 mol of the monomer having a π-conjugated double bond. is there. If the amount is less than 0.1 mol, the degree of polymerization of the monomer decreases, making it difficult to separate and recover the polymer fine particles. On the other hand, if the amount is 0.8 mol or more, the particles are aggregated to increase the particle size of the polymer fine particles, resulting in poor dispersion stability. To do.

The polymer fine particle production method is performed, for example, in the following steps:
(A) a step of preparing an emulsion by mixing and stirring an anionic surfactant, a nonionic surfactant, an organic solvent and water;
(B) a step of dispersing a monomer having a π-conjugated double bond in an emulsion,
(C) oxidative polymerization of the monomer,
(D) A step of separating the organic phase and collecting the polymer fine particles.

  Each of the above steps can be performed using means known to those skilled in the art. For example, the mixing and stirring performed at the time of preparing the emulsion is not particularly limited. For example, a magnetic stirrer, a stirrer, a homogenizer, or the like can be selected as appropriate. The polymerization temperature is 0 to 25 ° C, preferably 20 ° C or less. If the polymerization temperature exceeds 25 ° C., side reactions occur, which is not preferable.

  When the oxidative polymerization reaction is stopped, the reaction system is divided into an organic phase and an aqueous phase. At this time, unreacted monomers, oxidizing agents and salts remain dissolved in the aqueous phase. When the organic phase is separated and recovered and washed several times with ion-exchanged water, reducing polymer fine particles dispersed in an organic solvent can be obtained.

  The polymer fine particles obtained by the above production method are fine particles mainly composed of a polymer of a monomer derivative having a π-conjugated double bond and containing an anionic surfactant and a nonionic surfactant. And the characteristic is that it has a fine particle size and is dispersible in an organic solvent. The polymer fine particles are spherical fine particles, and the average particle size is preferably 10 to 100 nm. By making fine particles with a small average particle diameter as described above, the surface area of the fine particles becomes extremely large, and even with fine particles of the same mass, more catalytic metals can be adsorbed, thereby reducing the thickness of the coating layer. It becomes possible. The conductivity of the obtained polymer fine particles is less than 0.01 S / cm, and preferably 0.005 S / cm or less.

  The reductive polymer fine particles dispersed in the organic solvent thus obtained can be used as the reductive polymer fine particle component of the coating as it is, after being concentrated or dried.

(2) Method for Producing Conductive Polymer Fine Particles The conductive polymer fine particles used are, for example, π in an O / W type emulsion obtained by mixing and stirring an organic solvent, water and an anionic surfactant. -It can be produced by adding a monomer having a conjugated double bond and subjecting the monomer to oxidative polymerization.

  Examples of the monomer having an π-conjugated double bond and the anionic surfactant are the same as those exemplified in the production of the reducing fine particles, and preferably pyrrole, aniline, thiophene and 3,4- Ethylenedioxythiophene etc. are mentioned, More preferably, pyrrole is mentioned.

  The amount of the anionic surfactant in the reaction system is preferably less than 0.2 mol, more preferably 0.05 mol to 0.15 mol, with respect to 1 mol of the monomer having a π-conjugated double bond. If the amount is less than 0.05 mol, the yield and dispersion stability decrease, while if the amount is 0.2 mol or more, the resulting conductive polymer fine particles may have a humidity dependency on the conductivity.

  In the production, the organic solvent forming the organic phase of the emulsion is preferably hydrophobic. Among these, toluene and xylene, which are aromatic organic solvents, are preferable from the viewpoint of the stability of the O / W emulsion and the affinity with the monomer. Although the amphoteric solvent can polymerize a monomer having a π-conjugated double bond, it becomes difficult to separate the organic phase and the aqueous phase when the produced conductive polymer fine particles are recovered.

  The ratio of the organic phase to the aqueous phase in the emulsion is preferably 75% by volume or more in the aqueous phase. When the water phase is 20% by volume or less, the amount of the monomer having a π-conjugated double bond is reduced, and the production efficiency is deteriorated.

  Examples of the oxidizing agent used in the production include the same as those exemplified in the production of the reducing fine particles, but a particularly preferred oxidizing agent is a persulfate such as ammonium persulfate. The amount of the oxidizing agent in the reaction system is preferably 0.1 mol or more and 0.8 mol or less, more preferably 0.2 to 0.6 mol with respect to 1 mol of the monomer having a π-conjugated double bond. is there. If the amount is less than 0.1 mol, the degree of polymerization of the monomer decreases, making it difficult to separate and collect the conductive polymer fine particles. , Dispersion stability deteriorates.

The method for producing the conductive polymer fine particles is performed, for example, in the following steps:
(A) a step of preparing an emulsion by mixing and stirring an anionic surfactant, an organic solvent and water;
(B) a step of dispersing a monomer having a π-conjugated double bond in an emulsion,
(C) a step of oxidatively polymerizing the monomer and causing the anionic surfactant to contact and adsorb the polymer fine particles;
(D) A step of separating the organic phase and collecting the conductive polymer fine particles.

  Each of the above steps can be performed using means known to those skilled in the art. For example, the mixing and stirring performed at the time of preparing the emulsion is not particularly limited. For example, a magnetic stirrer, a stirrer, a homogenizer, or the like can be selected as appropriate. The polymerization temperature is 0 to 25 ° C, preferably 20 ° C or less. If the polymerization temperature exceeds 25 ° C., side reactions occur, which is not preferable.

  When the oxidative polymerization reaction is stopped, the reaction system is divided into an organic phase and an aqueous phase. At this time, unreacted monomers, oxidizing agents and salts remain dissolved in the aqueous phase. When the organic phase is separated and recovered and washed several times with ion-exchanged water, conductive polymer fine particles dispersed in an organic solvent can be obtained.

  The conductive polymer fine particles obtained by the above production method are fine particles mainly composed of a monomer derivative having a π-conjugated double bond and containing an anionic surfactant. And the characteristic is that it can disperse | distribute in a fine particle size and an organic solvent. The polymer fine particles are spherical fine particles, and the average particle size is preferably 10 to 100 nm. By using fine particles with a small average particle size as described above, the surface area of the fine particles becomes extremely large, and even with fine particles of the same mass, more catalyst metal can be adsorbed when dedoped and reduced. Thus, the coating layer can be made thin.

  Moreover, you may manufacture the manufacturing method of electroconductive polymer microparticles | fine-particles by the method described in Unexamined-Japanese-Patent No. 2008-214401.

  The conductive polymer fine particles dispersed in the organic solvent thus obtained can be used as the conductive polymer fine particle component of the coating as it is, after being concentrated or dried.

  EXAMPLES Next, although an Example demonstrates this invention still in detail, this invention is not limited to an Example.

Production Example 1: Preparation of conductive polypyrrole fine particles (dispersion) 1.5 mmol of di-2-ethylhexyl sodium sulfosuccinate was dissolved in 100 mL of ion-exchanged water, and then 21.2 mmol of pyrrole monomer was added and stirred for 30 minutes. . 50 mL (corresponding to 6 mmol) of 2M aqueous ammonium persulfate solution was added, and the reaction was performed for 20 minutes. Then 25 mL of toluene was added and stirred for 4 hours. After completion of the reaction, the organic layer is collected and washed several times with ion exchange water to obtain a conductive fine particle dispersion dispersed in toluene, and the solid content concentration of the conductive fine particles is adjusted to 0.6% with toluene. did. The average particle size of the conductive fine particles in the conductive fine particle dispersion was 20 nm.

Production Example 2: Preparation of Base Paint A base paint containing the conductive polypyrrole fine particles shown in Table 1 was prepared by adding binders A and B in various parts by mass to the conductive polypyrrole fine particle dispersion prepared in Production Example 1.
Here, the binders A and B in Table 1 mean the following, and the amount of the binder used indicates the number of parts by mass of the binder used with respect to 1 part by mass of the conductive polypyrrole fine particles.
A: Super Becamine J-820: Melamine (Dainippon Ink Chemical Co., Ltd.)
B: Byron 240: Polyester (Toyobo Co., Ltd.)

Production Example 3: Formation of Coating Film Coating Films having Various Film Thicknesses shown in Table 2 shown in Table 2 by coating the coating materials 1 to 6 prepared on the base material using soft films C and D as the base material A soft film having a layer formed thereon was produced. The coating films 1 to 11 in Table 2 were coated with a paint and dried at 120 ° C. for 5 minutes to form a coating film layer in which fine particles were uniformly dispersed.
The soft films C and D in the table mean the following.
C: Resin PET, trade name Cosmo Shine A4100, manufactured by Toyobo Co., Ltd. D: Resin PI, trade name Kapton 200H, manufactured by Toray DuPont Co., Ltd.

Production Example 4: Production of plated product by electroless plating method The film (coating 1 to 11) on which the coating layer produced above was formed was immersed in 1M aqueous sodium hydroxide solution at 35 ° C. for 5 minutes, The conductive polymer fine particles were made reducible by washing with washing water. Next, it was immersed in a 0.02% palladium chloride-0.01% hydrochloric acid aqueous solution at 35 ° C. for 5 minutes and then washed with tap water. Next, the film was dipped in an electroless copper plating bath ATS Adcopper IW bath (Okuno Pharmaceutical Co., Ltd.), and dipped at 35 ° C. for 10 minutes for copper plating.

Production Example 5: Production of sheet-like elastic body (foamed sheet) 430.17 g of polytetramethylene glycol having a number average molecular weight of 1000, 41.24 g of all in 1,3 butane, 320.88 g of 4,4-diphenylmethane diisocyanate, 198 ethyl acetate .86 g was stirred and reacted in a nitrogen gas atmosphere at 80 ° C. for 3 hours to obtain a prepolymer solution of a terminal isocyanate group having an NCO% of 4.2%.
8. Next, Actcol (produced by Mitsui Takeda Chemicals Co., Ltd., glycerin-based propylene oxide ethylene oxide adduct having a hydroxyl value of 24) in an amount to make the NCO% of the prepolymer to 3.5 with respect to 100 g of the prepolymer solution obtained above. 15 g, Crisbon Assistor SD-7 (Dainippon Ink Co., Ltd., foam stabilizer; silicon-based) 0.88 g, dibutyltin laurate and 0.18 g of pentamethyldiethylenetriamine are mixed, and 3 minutes per minute in a 200 mL polyethylene container. The mixture was stirred for 60 seconds with a four-blade agitator rotating at 1,000 rpm.
The obtained mixed solution is coated on the plated product produced in the above to a thickness of about 0.2 mm, and the reaction is carried out in a humidified oven at 110 ° C. for 2 minutes to form a polyurethane urea foam sheet (sheet-like elastic body). Got. In addition, the thickness of the obtained polyurethane urea foam sheet is about 0.3 mm.
In addition, what provided the foam sheet on the copper plating film (indicated by "plating film thickness" in Table 3) formed on the coating films 1 to 11 (displayed as "present" in Table 3). Examples 1 to 14 were used. Moreover, the comparative example 4 is the plated product manufactured from the coating film 1, and does not provide the foam sheet (in Table 3, it displays as a foam sheet "nothing").

  Comparative Example 1 uses a small vacuum vapor deposition apparatus “VPC-260F” (manufactured by ULVAC Kiko Co., Ltd.) to deposit copper on the soft film sheet C, and then laminates the foamed sheet on the copper layer. It has been made.

  In Comparative Example 2, the above foamed sheet was laminated on the flexible film sheet C, and then the copper was vacuumed on the foamed sheet using a small vacuum deposition apparatus “VPC-260F” (manufactured by ULVAC Kiko Co., Ltd.). Evaporated.

  In Comparative Example 3, the soft film sheet C was immersed in an OPC-1050 conditioner (Okuno Pharmaceutical Co., Ltd.) as a pretreatment liquid at 60 ° C. for 5 minutes, then washed with tap water, and then ATS precondition PIW- 1 (manufactured by Okuno Pharmaceutical Co., Ltd.) for 2 minutes at 45 ° C., followed by washing with tap water, and then 5 minutes at 60 ° C. in an ATS Condicrine CIW-2 bath (manufactured by Okuno Pharmaceutical Industries, Ltd.). After soaking for 20 minutes, it is washed with tap water, then immersed in an OPC-SALM bath (Okuno Pharmaceutical Co., Ltd.) for 2 minutes as a pre-dip solution, washed with tap water, As a list liquid, it was immersed in an OPC-80 catalyst bath (Okuno Pharmaceutical Co., Ltd.) for 6 minutes at 25 ° C. and then washed with tap water. Next, as an activator, an OPC-500 accelerator MX bath ( (Okuno Pharmaceutical Co., Ltd.) After immersing for 30 minutes, rinse with tap water, and then immersed in an electroless copper plating bath ATS Adcopper IW bath (Okuno Pharmaceutical Co., Ltd.) for 20 minutes at 35 ° C. A metal plating film was formed. The foamed sheet is laminated on the metal plating film.

Test example 1
Various evaluation tests were performed on the plated products of Examples 1 to 14 and Comparative Examples 1 to 4 manufactured above, and the results are summarized in Table 3.
The evaluation test items, evaluation methods and evaluation criteria are as follows.
-Metal appearance The state of the plating film before providing a foam sheet was observed visually, and the substrate exposed area was measured. The evaluation criteria were as follows.
○: Completely covered and no substrate exposed △: About 50% substrate exposed ×: 100% substrate exposed / electromagnetic shielding The average value of the results measured in the frequency band of 1 MHz to 1 GHz by the KEC method is electromagnetic waves It was shown as the value of shielding property.
-Electromagnetic wave shielding property after bending test The obtained sample was cut into a length of 200 mm and a width of 100 mm to obtain a test sample. Next, prepare a cylindrical shaft made of stainless steel with a shaft system of 10 mmφ and a length of 300 mm, align one end with the longitudinal direction of the test sample, and wind it so that the plating part is on the outside. Next, wrap so that the plating part is inside. The electromagnetic wave shielding property was measured after repeating this operation as one set and 100 sets.
-Electromagnetic wave shielding property after abrasion resistance test A plane friction tester ("FR-2S" manufactured by Suga Test Instruments Co., Ltd.) was used. The sample is fixed to the test specimen table with the foam surface (metal layer surface) facing upward, and a friction cloth (cotton canvas No. 6) is attached to the friction element. The load was 500 g, and the electromagnetic shielding properties of the test piece after being rubbed 1000 times were measured.
-Discoloration after corrosion resistance test The sample was left for 1 week in an environment with a humidity of 95% x 70 ° C and the discoloration of the copper plating part was observed. The evaluation criteria were as follows.
○: No corrosion Δ: Slightly corrosive ×: Severe corrosion / Electromagnetic shielding after corrosion resistance test The sample was left in an environment of humidity 95% × 70 ° C. for 1 week to measure electromagnetic shielding.

Claims (3)

A coating layer containing conductive fine polymer particles and a binder is formed on the surface of the substrate,
A metal plating film is formed on the coating layer by an electroless plating method,
A sheet-like elastic body is formed on the metal plating film,
The electromagnetic wave shielding gasket , wherein the sheet-like elastic body is a polyurethane urea foam sheet .   The binder is present in an amount of 0.1 to 10 parts by mass with respect to 1 part by mass of the conductive polymer fine particles, and the thickness of the coating layer is 20 to 500 nm. Gasket for electromagnetic shielding. 3. The electromagnetic wave shielding gasket according to claim 1, wherein the sheet-like elastic body is formed by coating a raw material of the sheet-like elastic body onto the metal plating film.