JP2010106391A - Metal-plated fiber structure and metal structure obtained by sintering the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metal-plated fiber structure that is resistant to the peeling of plated layer and has suppressed plating unevenness. <P>SOLUTION: The metal-plated fiber structure is a fiber structure having a fiber surface plated with a metal. A fiber constituting the fiber structure contains a fiber having an ethylene-vinyl alcohol copolymer exposed at least at part of the surface of the fiber. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a metal-plated fiber structure in which metal is plated on a fiber, and more particularly to a metal-plated fiber structure in which metal is plated on a fiber containing an ethylene-vinyl alcohol copolymer.

  Conventionally, as a material in which a metal is plated on a material made of a synthetic resin, a material in which metal is plated on a material to be plated such as a nonwoven fabric containing a urethane porous body, polyolefin, or polyester fiber is known.

  Patent Document 1 discloses a nickel-plated non-woven electrode substrate obtained by performing nickel plating on a non-woven web mainly composed of a heat-fusible composite fiber in which low-melting fibers are arranged outside high-melting fibers. However, since the insulating and porous nonwoven fabric is subjected to metal plating, there is a problem that the metal plating is easily peeled off. Patent document 2 is disclosing the electrical power collector for batteries provided with the nonwoven fabric and the plating film formed on the surface of the nonwoven fabric. However, as in Patent Document 2, a non-woven fabric that is a material to be plated is subjected to hydrophilization treatment such as sulfonation treatment, fluorine gas treatment, vinyl monomer graft polymerization, surfactant treatment, discharge treatment, or hydrophilic resin application treatment. In the case of any of the hydrophilization treatments, the hydrophilic group cannot be uniformly introduced into the entire nonwoven fabric, resulting in uneven introduction of the hydrophilic group, resulting in uneven plating. There was a problem that a part which is generated or not plated is generated. Further, when the hydrophilic treatment is not performed, there is a problem that the metal plating is easily peeled off.

Patent Document 3 discloses a method for producing a metal-plated nonwoven electrode substrate obtained by subjecting a web mainly composed of conductive organic fibers to hydroentanglement and then electroplating. However, Patent Document 3 discloses that organic fibers are attached to organic fibers by a method of attaching a conductive polymer to organic fibers, a method of attaching conductive carbon together with a binder polymer, or a method of using carbon fibers having conductivity per se. Since plating is performed after imparting conductivity and hydroentanglement treatment, there is a problem that unevenness occurs in imparting conductivity, resulting in uneven plating or unplated portions.
JP-A-8-250125 JP 2003-109600 A JP-A-6-275281

  In order to solve the above-mentioned conventional problems, the present invention provides a metal-plated fiber structure in which plating is difficult to peel and plating unevenness is small.

  The metal-plated fiber structure of the present invention is a fiber structure in which a metal is plated on the fiber surface, and the fiber constituting the fiber structure has an ethylene-vinyl alcohol copolymer on at least a part of the fiber surface. It is characterized by including exposed fibers.

  Since the present invention includes a fiber in which an ethylene-vinyl alcohol copolymer is exposed on at least a part of the fiber surface, it is possible to provide a metal-plated fiber structure in which plating is difficult to peel and plating unevenness is small.

The present inventors have studied the metal plating on the fiber structure, focusing on the plating unevenness is a conventional problem. Specifically, with regard to ordinary polyolefin fibers, focusing on the fact that metal-plated parts are likely to occur at the intersections and contacts of the fibers, and that metal plating is uneven, ethylene-vinyl alcohol copolymer is present on the fiber surface. Then, it discovered that a metal plating fiber structure and a nonwoven fabric with little plating unevenness could be obtained. That is, the metal-plated fiber structure of the present invention includes fibers in which the ethylene-vinyl alcohol copolymer is exposed on at least a part of the fiber surface as the fibers constituting the fiber structure, so that the plating is difficult to peel off, And there is little plating unevenness.

  The fiber (hereinafter also referred to as a fiber to be plated) constituting the fiber structure of the present invention is a fiber (hereinafter also referred to as an EVOH fiber) in which an ethylene-vinyl alcohol copolymer is exposed on at least a part of the fiber surface. Including. With such a configuration, due to the action of attracting the cation of the hydroxyl group of the ethylene-vinyl alcohol copolymer exposed on the fiber surface, the metal plating is easily fixed, the metal plating is difficult to peel off, and the plating unevenness Less.

The present invention has a configuration including fibers in which an ethylene-vinyl alcohol copolymer is exposed on at least a part of the fiber surface of the fiber to be plated. With such a configuration, since the fiber to be plated includes EVOH fiber having a hydroxyl group on the fiber surface itself, the plating metal is easily fixed particularly due to the hydroxyl group of the vinyl alcohol unit, and plating unevenness is reduced. In addition, even when the fiber to be plated is subjected to a hydrophilic treatment and / or a conductive treatment and then subjected to a plating treatment, due to the hydroxyl group on the fiber surface, the hydrophilicity is obtained by the hydrophilic treatment and / or the conductive treatment. And conductivity can be uniformly imparted, and plating unevenness is reduced. Furthermore, fiber intersections and fiber contacts that are difficult to hydrophilize and / or electrically conductive may not be able to uniformly impart hydrophilicity or electrical conductivity, but even in that case, due to the hydroxyl groups of EVOH fibers. , Plating unevenness is reduced.
Further, the present invention is excellent in chemical resistance due to the ethylene unit of the ethylene-vinyl alcohol copolymer. Chemical resistance refers to, for example, acid resistance, alkali resistance, and the property that main chain decomposition due to oxidation / reduction hardly occurs.

  The ethylene-vinyl alcohol copolymer can be obtained by saponifying an ethylene vinyl acetate copolymer. Examples of commercially available products include Kuraray's product name “EVAL”, Nippon Synthetic Chemical Industry's product name “Soarnol”, and the like, and these commercially available products can be used in the present invention.

It is preferable that melting | fusing point of the said ethylene-vinyl alcohol copolymer is 100 to 190 degreeC, More preferably, it is 120 to 175 degreeC, More preferably, it is 130 to 155 degreeC. When an ethylene-vinyl alcohol copolymer having a melting point of 100 ° C. or higher is used, it is easy to form fibers, and when an ethylene-vinyl alcohol copolymer having a melting point of 190 ° C. or lower is used, it is relatively Heat treatment can be performed at a low temperature.
In order to obtain an ethylene-vinyl alcohol copolymer having a melting point in the above range, for example, an ethylene-vinyl alcohol copolymer having an ethylene content described later may be used. The melting point of the ethylene-vinyl alcohol copolymer varies depending on the contents of the ethylene units and vinyl alcohol units contained therein, and the ethylene-vinyl alcohol copolymer tends to have a lower melting point as the ethylene content increases. When the amount decreases, the melting point of the ethylene-vinyl alcohol copolymer tends to increase.

  The ethylene content of the ethylene-vinyl alcohol copolymer is preferably 25 mol% or more and less than 80 mol%, more preferably 30 mol% or more and less than 70 mol%, still more preferably 45 mol% or more and less than 65 mol%. When the ethylene content is 25 mol% or more, the thermal stability is good and the fiber is easily formed. When the ethylene content is less than 80 mol%, sufficient hydrophilicity can be obtained, and plating unevenness hardly occurs. Further, when the ethylene content is decreased, hydrophilicity is easily obtained, but the solubility in water is increased and the shape stability tends to be deteriorated.

  Moreover, when bonding the intersection and / or contact of the fiber which are mentioned later, it is preferable that the ethylene content of an ethylene-vinyl alcohol copolymer is 25 mol% or more and less than 80 mol%. A more preferable range is as described above. When the ethylene content is in the range of 25 mol% or more and less than 80 mol%, when the EVOH fiber is subjected to heat treatment in a wet state or in the presence of moisture or water vapor, the ethylene-vinyl alcohol copolymer swells and softens apparently. In addition, the phenomenon of solidifying when cooled to room temperature (hereinafter also referred to as gelation) can be used to bond the intersections and contacts of the fibers.

The EVOH fiber of the present invention is a fiber in which the ethylene-vinyl alcohol copolymer is exposed on at least a part of the fiber surface. From the viewpoint of making it difficult to peel off the plating, the EVOH fiber is 10% of the fiber surface as viewed from the fiber cross section. The ethylene-vinyl alcohol copolymer is preferably exposed as described above. Here, the term “exposed to at least part of the fiber surface” means that it is exposed to at least part of the surface of the fiber as viewed from the fiber cross section. For example, single fibers, side-by-side composite fibers, core-sheath composite fibers, sea-island composite fibers, composite fibers such as split-type composite fibers, and component random dispersion fibers such as polymer alloys can be used.
Moreover, it is more preferable that the exposed portion of the ethylene-vinyl alcohol copolymer has a configuration that is continuous in the fiber length direction. When the exposed portion of the ethylene-vinyl alcohol copolymer is continuous in the length direction of the fiber, since the hydroxyl group exists throughout the length direction of the fiber, plating unevenness is further reduced.

  The EVOH fiber of the present invention is preferably a core-sheath type composite fiber whose sheath component is an ethylene-vinyl alcohol copolymer. In addition, it is preferable that a sheath component contains 70 mass% or more of ethylene-vinyl alcohol copolymers, and it is most preferable that a sheath component consists only of ethylene-vinyl alcohol copolymers. When the EVOH fiber is a core-sheath type composite fiber whose sheath component is an ethylene-vinyl alcohol copolymer, the ethylene-vinyl alcohol copolymer is exposed over the fiber surface, and hydroxyl groups are present over the fiber surface. Since the exposed portion of the ethylene-vinyl alcohol copolymer is continuous also in the length direction of the fiber, the metal plating is more easily fixed and plating unevenness is reduced. Further, when the EVOH fiber is in the form of a core-sheath type composite fiber, it can be particularly suitably used as a heat-sealing fiber used for a nonwoven fabric subjected to metal plating.

  When the EVOH fiber is a core-sheath type composite fiber, the melting point of the core component of the core-sheath type composite fiber is preferably higher by 10 ° C. than the melting point of the sheath component, and the melting point of the core component is 20 ° C. higher than the melting point of the sheath component. It is more preferable. If the melting point of the core component is 10 ° C. or higher than the melting point of the sheath component, heat treatment at a temperature at which only the sheath component is fused can fuse only the sheath component and obtain a metal-plated fiber structure having an appropriate void. it can.

  When EVOH fiber is a core-sheath type composite fiber, the core component is not particularly limited. For example, polyolefin components such as polyethylene, polypropylene, polymethylpentene, polybutene, and ethylene-propylene copolymer, polyethylene terephthalate, polybutylene terephthalate Polytrimethylene terephthalate, polybutylene succinate, polyester components such as polylactic acid, and polyamide components such as nylon 6 and nylon 66 may be used alone or in combination. Among these, from the viewpoint of chemical resistance, the core component is preferably a polyolefin-based component, and the core component is most preferably polypropylene. Chemical resistance refers to, for example, acid resistance, alkali resistance, and the property that main chain decomposition due to oxidation / reduction hardly occurs.

  When the EVOH fiber is a core-sheath composite fiber, the sheath component may contain other components other than the ethylene-vinyl alcohol copolymer at less than 30% by mass. As the other components, the components mentioned as the core component can be used. Also, when other components are included, it is advantageous to make the sheath component a masterbatch before fiberization.

  When the EVOH fiber is a core-sheath type composite fiber, the volume ratio of each component constituting the core-sheath type composite fiber is not particularly limited, and there may be an amount sufficient to constitute each component. The ratio is preferably 2/8 to 8/2, more preferably 4/6 to 6/4, and most preferably 4.5 / 5.5 to 5.5 / 4.5. preferable. When the volume ratio of the composite fiber is in the range of 2/8 to 8/2, the fiber spinnability is good and the plating property is also good.

  The fiber constituting the fiber structure of the present invention includes a fiber in which an ethylene-vinyl alcohol copolymer is exposed on at least a part of the fiber surface. The more EVOH fibers are present in the fibers constituting the fiber structure, the more difficult the plating is to peel off and the less the plating unevenness becomes more prominent. More preferably, the fiber contains 25% by mass or more of the fiber in which the ethylene-vinyl alcohol copolymer is exposed on at least a part of the fiber surface.

  The to-be-plated fibers may be used by mixing EVOH fibers and other fibers. In this case, the fibers constituting the fiber structure include 25% by mass or more and 90% by mass or less of fibers in which the ethylene-vinyl alcohol copolymer is exposed on at least a part of the fiber surface, and 10% by mass of other fibers. More than 75 mass% is preferable. Moreover, when EVOH fiber is a form of the above-mentioned core-sheath-type composite fiber, it is preferable to use EVOH fiber for adhesion | attachment of the intersection of fibers from a viewpoint of making the intersection of fibers easy to plate. Moreover, the fiber which comprises a fiber structure contains 30 mass% or more and 90 mass% or less of EVOH fiber from a viewpoint of reducing the excessive fusion | bonding of fibers other than fiber intersections, and 10 mass% or more and 70 mass% of other fibers. %, More preferably 40 to 80% by mass of EVOH fiber, and particularly preferably 20 to 60% by mass of other fibers.

  When the EVOH fiber is a core-sheath type composite fiber, the other fiber used by mixing with the EVOH fiber may be a fiber having a melting point of 100 ° C. or higher and 300 ° C. or lower. When it is desired to securely bond, fibers having a melting point of 100 ° C. or higher and 160 ° C. or lower can be used as the other fibers. For example, it is a core-sheath type composite fiber whose melting point of the sheath component is 100 ° C. or higher and 160 ° C. or lower. In addition, when it is desired to avoid excessive fusion between fibers or contraction of the fibers, fibers having a melting point of 160 ° C. or higher and 300 ° C. or lower can be used as the other fibers. For example, it is a single fiber having a melting point of 160 ° C. or higher and 300 ° C. or lower.

  Further, other fibers used by mixing with EVOH fibers are not particularly limited. For example, polyolefin components such as polyethylene, polypropylene, polymethylpentene, polybutene, and ethylene-propylene copolymer, polyethylene terephthalate, and polybutylene terephthalate. Of single fiber selected from the group of polyester-based components such as polytrimethylene terephthalate, polybutylene succinate, polylactic acid, and polyamide-based components such as nylon 6 and nylon 66, or a composite fiber fiber combining two or more types, You may use 1 type or in mixture of 2 or more types. Among these, from the viewpoint of excellent chemical resistance, a fiber made of a polyolefin-based component is preferable, and a fiber containing polypropylene is more preferable.

  Next, the EVOH fiber production method of the present invention will be described using a core-sheath type composite fiber as an example. First, a sheath component and a core component are prepared. Here, when the sheath component and / or the core component is composed of a plurality of components, it may be provided in the form of a masterbatch. Then, the sheath component and the core component are composite-spun using a conventional melt-spinning machine using an appropriate composite spinning nozzle so that a desired fiber cross-sectional structure can be obtained. The spinning temperature (nozzle temperature) is preferably 220 ° C. or higher and 320 ° C. or lower.

  The EVOH fiber used in the present invention preferably has a single fiber fineness of 0.01 to 100 dtex, more preferably a single fiber fineness of 0.1 to 10 dtex. When the single fiber fineness is 100 dtex or more, stable fiberization or nonwoven fabric formation may be difficult, and when the single fiber fineness is 0.01 dtex or less, metal plating may be difficult to fix to the fiber.

  Although the form of the fiber structure which consists of a to-be-plated fiber is not specifically limited, For example, filaments, such as a short fiber and a long fiber, a woven fabric, a knitted fabric, a nonwoven fabric, etc. may be sufficient. Especially, it is preferable that the form of the fiber structure which consists of to-be-plated fiber is a nonwoven fabric. Examples of the nonwoven fabric include spunbond nonwoven fabric, meltblown nonwoven fabric, chemical bond nonwoven fabric, airlaid nonwoven fabric, air-through nonwoven fabric, thermal bond nonwoven fabric, needle punch nonwoven fabric, hydroentangled nonwoven fabric, and the like.

  When the fiber structure is made of a nonwoven fabric, the intersection point and / or the contact point between the fibers of the nonwoven fabric made of the fiber to be plated may be bonded from the viewpoint of reducing the peeling of the metal plating at the intersection point and / or the contact point between the fibers. preferable. The bonding method is not particularly limited as long as the fibers are fixed to each other. For example, a method of heat-bonding by performing heat treatment at a temperature equal to or higher than the melting point of the component exposed on the fiber surface, or exposed on the fiber surface. And a method of gelling and fixing the ethylene-vinyl alcohol copolymer. In addition, the heat processing temperature in a gelling process may be below melting | fusing point of an ethylene-vinyl alcohol copolymer, or may be more than melting | fusing point. Among these, it is advantageous that the heat treatment temperature in the gelation treatment is equal to or higher than the melting point of the ethylene-vinyl alcohol copolymer, so that gel fixation and thermal bonding can be performed simultaneously.

Preferably the nonwoven fabric density of the plated nonwoven is in the range of 0.001~0.8g / cm ^3, more preferably in the range of 0.01 to 0.5 g / cm ^3. With such a configuration, it is easy to obtain the air permeability of a metal structure described later.

  The form of the metal-plated fiber structure of the present invention may be filaments such as short fibers and long fibers, woven fabrics, knitted fabrics, non-woven fabrics and the like. Especially, it is preferable that the form of a metal plating fiber structure is a nonwoven fabric. Examples of the nonwoven fabric include spunbond nonwoven fabric, meltblown nonwoven fabric, chemical bond nonwoven fabric, airlaid nonwoven fabric, air-through nonwoven fabric, thermal bond nonwoven fabric, needle punch nonwoven fabric, hydroentangled nonwoven fabric, and the like.

  When the metal-plated fiber structure of the present invention is a metal-plated nonwoven fabric, a nonwoven fabric is used as the fiber to be plated (hereinafter, also referred to as a nonwoven fabric to be plated), and the metal-plated nonwoven fabric may be subjected to metal plating treatment, Alternatively, it may be a mixed cotton nonwoven fabric of the metal plating fiber of the present invention and other fibers.

The to-be-plated fiber used by this invention may give a hydrophilic treatment as needed. Examples of the hydrophilic treatment include sulfonation treatment, fluorine gas treatment, corona treatment, plasma treatment, surfactant treatment, graft polymerization treatment, and hydrophilic resin treatment. The to-be-plated fiber of this invention originates in EVOH fiber, and is easy to be hydrophilized at the time of these hydrophilic treatments, or a hydrophilic group is easy to be introduced.
Moreover, since the ethylene-vinyl alcohol copolymer is exposed on the fiber surface, the to-be-plated fiber of this invention can perform a metal-plating process without a hydrophilic treatment.

  Next, the plating process will be described. Although the metal plated on the to-be-plated fiber of this invention is not specifically limited, For example, gold | metal | money, silver, copper, platinum, rhodium, nickel, chromium, cobalt, tin, zinc, cadmium etc. are mentioned. The plating treatment may be a method for forming a metal film on the fiber to be plated, such as an electroless plating method, an electrolytic plating method, a molten metal plating method, a vacuum deposition method, a chemical vapor deposition method, a physical vapor deposition method, a thermal spraying method, etc. Is mentioned. Among these, it is preferable to form the metal film in a two-step process of an electroless plating method and then an electrolytic plating method. When plating is performed in this two-step process, even a non-metallic material can be easily plated to a uniform thickness, and the metal fixing speed is high.

The electroless plating method will be described. The electroless plating method may be performed first in the order of the catalyzing step and then the electroless plating step. The catalyzing step is a step of imparting a catalyst to the surface of the fiber to be plated. For example, a method for providing a catalyst is a method in which a fiber to be plated is treated with a hydrochloric acid aqueous solution of stannous chloride and then catalyzed with an aqueous hydrochloric acid solution of palladium chloride, or fixed only with a hydrochloric acid solution of palladium chloride containing an amino group of a curing agent. And the like. Among these, the former method is preferable from the viewpoint of making the plating film thickness uniform.
The electroless plating step is a step of forming a metal film using an electroless plating solution containing a solvent containing a metal to be deposited and a reducing agent. In addition, you may add a complexing agent, a pH adjuster, a buffering agent, a promoter, a stabilizer, an improving agent, etc. to an electroless-plating liquid as needed. The solvent containing the metal to be deposited is not particularly limited as long as it is a metal salt. For example, in the case of forming a film of nickel, examples thereof include nickel sulfate, nickel chloride, nickel nitrate, nickel sulfamate, and the reducing agent is Examples thereof include hydrazine derivatives such as hydrazine hydrochloride, hydrazine sulfate, and hydrazine hydrate, hydrazine, sodium hypophosphite, dimethylamine borane, and the like.

  The electrolytic plating method will be described. Electroplating is a method in which a metal is deposited on a cathode by electrolysis using a plating bath in which a metal salt is dissolved. Here, the cathode is made of a fiber to be plated. The anode is appropriately selected depending on the plating bath and the metal to be deposited.

A plating bath used for electrolytic plating will be described. For example, in the case of electrolytic nickel plating, nickel sulfate, nickel chloride, boric acid is the main composition Watt bath, nickel chloride, boric acid is the main composition chloride bath, nickel chloride, nickel sulfamate, boric acid. A sulfamic acid bath having a composition, nickel borofluoride, a borofluoride bath having a main composition of boric acid, or the like may be used. Of these, electrolytic nickel plating is preferably performed using a Watt bath from the viewpoint of a high reaction rate and excellent productivity.
In addition, the above-described electrolytic plating bath may contain primary brighteners such as sodium 1,5-naphthalenedisulfonate, saccharin, p-toluenesulfonamide, 1,4-butynediol, propargyl alcohol, coumarin, ethylene cyanide as required. A secondary brightener such as hydrin and a surfactant such as sodium dodecyl sulfate may be added.

  In the case of electrolytic copper plating, copper sulfate, a copper sulfate bath whose main composition is sulfuric acid, copper borofluoride, a copper borofluoride bath whose main composition is tetrafluoroboric acid, copper cyanide, sodium cyanide, sodium hydroxide A copper cyanide bath in which is the main composition, cupric pyrophosphate, potassium pyrophosphate, and a copper pyrophosphate bath in which ammonia is the main composition may be used.

  In the case of electrolytic chromium plating, a Sargent bath whose main composition is chromium (VI) oxide and sulfuric acid, and a silicic acid bath whose main composition is chromium (VI) oxide, sulfuric acid and silicic acid may be used.

  For electrolytic galvanization, zinc sulfate, aluminum sulfate, sodium chloride, zinc sulfate bath mainly composed of boric acid, zinc chloride, zinc chloride bath mainly composed of ammonium chloride, zinc cyanide, sodium cyanide, water A cyan bath whose main composition is sodium oxide, a zincate bath whose main composition is zinc oxide and sodium hydroxide may be used.

  In the case of electrolytic tin plating, sulfuric acid bath whose main composition is tin sulfate, sulfuric acid, cresol sulfonic acid, formalin, tin borofluoride, tetrafluoroboric acid, borofluoride bath whose main composition is formalin, potassium stannate, hydroxide A basic tin plating bath in which potassium is the main composition may be used.

  In the case of electrolytic gold plating, a cyanogen bath in which the main composition is potassium gold cyanide and potassium cyanide, a neutral bath in which the main composition is potassium gold cyanide, sodium phosphate, and sodium hydrogen phosphate, An acidic bath whose main composition is monopotassium potassium and citric acid may be used.

  In the case of electrolytic silver plating, a strike bath whose main composition is silver cyanide, potassium cyanide, and potassium carbonate may be used.

  In the case of electrolytic rhodium plating, a sulfuric acid plating bath whose main composition is metal rhodium and sulfuric acid, and a phosphoric acid plating bath whose main composition is metal rhodium and phosphoric acid may be used.

  In the case of electrolytic platinum plating, the main components are platinum (IV) chloride, hydrogen phosphate amine, ammonium phosphate phosphate bath, platinum dinitrite, sodium nitrite, ammonium nitrate, and ammonia water. A diaminonitrite bath may be used.

The vacuum deposition method will be described. The vacuum deposition method is a method in which a metal or metal compound evaporated by heating at 10 ⁻⁵ to 10 ⁻⁶ Torr is attached to a fiber to be plated to form a metal plating film. Further, the vacuum evaporation method may be a method in which an evaporation substance is ionized partly or entirely by discharge plasma, an electron beam or the like and deposited on a substrate to which a negative charge is applied.

  The thermal spraying method will be described. The thermal spraying method is a method in which a metal is melted into fine particles and sprayed to form a film. Specifically, for example, an arc is generated by a direct current large current and low voltage between an anode and a cathode in a gas atmosphere such as argon, hydrogen, nitrogen, etc., and a plasma state is obtained. Examples include plasma spraying.

The metal structure of the present invention is formed by firing the metal-plated fiber structure of the present invention, and has an air permeability of 1 to ²⁰⁰ cm ³ / cm ² / sec. The air permeability of the metal structure is preferably ^{20 to} 100 cm ³ / cm ² / sec. When the air permeability of the metal structure is smaller than 1 cm ³ / cm ² / sec, the filling amount of particles, powder, liquid, etc. decreases, or the pressure loss for the liquid or gas increases. Also, if the air permeability of the metal structure is greater than 200 cm ³ / cm ² / sec, filling irregularities and dropping off of particles, powders, liquids, etc. are likely to occur, or the contact area with the liquid or gas tends to decrease. It is in.
The metal structure of the present invention is preferably formed by firing and carbonizing the components constituting the fiber. Such a configuration can be particularly suitably used for applications that require heat resistance and conductivity.

  Although a baking process is not specifically limited, For example, it can carry out by processing for 30 second-30 minutes at 700-2000 degreeC in inert gas atmosphere, such as nitrogen, helium, and argon.

  The metal-plated fiber of the present invention has functions such as decoration, deterioration resistance, heat resistance, wear resistance, conductivity, electromagnetic wave sealing characteristics, etc., depending on the metal plated on the fiber to be plated and the plating method. And the metal plating fiber of this invention can be utilized for an accessory, a filter, an electronic component, an electromagnetic wave sealing material, etc.

[Plating amount per unit area]
The mass of the plating pretreatment nonwoven W, mass W ₁ of plated nonwoven fabric after the electroless plating process, an electroless plating A ₁ and the area of the plating nonwoven fabric after treatment, electroless plating treatment W ₂ mass plating nonwoven after , the area of the plating nonwoven fabric after the electroless plating process when the a _2, was calculated from the following equation.
Electroless plating amount = (W ₁ −W) / A ₁
Electrolytic plating amount = (W ₂ −W) / A ₂

[Electric resistance]
HITOSTER (3531) manufactured by Hioki Electric Co., Ltd. is used for the plating nonwoven fabric after the electroless plating treatment and the plating nonwoven fabric after the electrolytic plating treatment, the resistance value is measured at 10 random locations, and the average value is calculated. Value. The frequency was measured at 10 kHz and the voltage was measured at 1.0 v.

[Plating unevenness]
About the plating nonwoven fabric after an electroless-plating process, the resistance value in 10 random places was measured.
A: The difference between the maximum value and the minimum value of 10 measured values was less than 10Ω.
B: The difference between the maximum value and the minimum value of 10 measured values was 10 or more and less than 50Ω.
C: The difference between the maximum value and the minimum value of 10 measured values was 50Ω or more.

[Air permeability]
The air permeability of the metal plating structure obtained by firing the metal plating fiber structure was measured according to JIS L-1096-6.27.1 A method.

(Fiber 1)
An ethylene-vinyl alcohol copolymer having a melting point of 142 ° C. and an ethylene content of 55 mol% (manufactured by Nippon Synthetic Chemical Industry, trade name “Soarnol SG649”), and a core component having a melting point of 165 ° C. (manufactured by Nippon Polypro Co., Ltd.) A core-sheath type composite fiber (core-sheath ratio 5: 5) having a trade name “SA03” was prepared. The fiber 1 had a fineness of 2.2 dtex and a fiber length of 51 mm.

(Fiber 2)
An ethylene-vinyl alcohol copolymer (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name “Soarnol K3835BN”) having a melting point of 173 ° C. and an ethylene content of 38 mol%, and a core component having a melting point of 165 ° C. A core-sheath type composite fiber (core-sheath ratio 5: 5) having a trade name “SA03” was prepared. The fiber 2 had a fineness of 2.2 dtex and a fiber length of 51 mm.

(Fiber 3)
A core-sheath type composite fiber (manufactured by Daiwabo Polytech Co., Ltd., trade name “NBF (H)”) having a sheath component of high-density polyethylene having a melting point of 136 ° C. and a core component of polypropylene having a melting point of 165 ° C. was prepared. The fiber 3 had a fineness of 2.2 dtex and a fiber length of 51 mm.

(Fiber 4)
A core-sheath type composite fiber (manufactured by Unitika Ltd., trade name “Melty”) in which the sheath component is a copolyester having a melting point of 126 ° C. and the core component is polyethylene terephthalate having a melting point of 260 ° C. was prepared. The fiber 4 had a fineness of 2.2 dtex and a fiber length of 51 mm.

Example 1
A card web consisting of only fiber 1 and having a basis weight of 50 g / m ² is prepared as a fiber to be plated, and hydroentangled at a water pressure of 3 MPa, and then dried at 145 ° C. for 12 seconds using an air-through dryer. Thus, a nonwoven fabric to be plated made of a nonwoven fabric was obtained. In addition, the to-be-plated nonwoven fabric of Example 1 was a nonwoven fabric in which the intersection of the fibers was bonded by gel fixation and thermal bonding.

  Next, the nonwoven fabric to be plated was catalyzed using an aqueous solution of 1% by mass of stannous chloride, 20% by mass of hydrochloric acid of 10 mol / L, and 0.1% by mass of palladium chloride.

  Plating to be catalyzed into an aqueous solution containing 20% by mass of nickel sulfate, 3% by mass of hydrazine of 20 mol / L as a reducing agent, 30% by mass of sodium citrate as a complexing agent, and 2% by mass of sodium hydroxide as a pH adjuster The nonwoven fabric was impregnated and electroless plating was performed. The electroless plating was performed at 60 ° C.

  Subsequently, an aqueous solution (watt bath) using 300% by mass of nickel sulfate, 50% by mass of nickel chloride, and 50% by mass of boric acid is impregnated with a non-plated non-plated nonwoven fabric, electroplated, and nickel plated. A nonwoven fabric was obtained. The electrolytic plating was performed at 60 ° C. with a current of 5 A flowing.

  FIG. 1 is an electron microscope (SEM) photograph (magnification 300) of the surface of a nonwoven fabric composed of the obtained plated fibers.

  Moreover, the obtained nickel plating nonwoven fabric was baked and the nickel nonwoven fabric was obtained.

(Example 2)
A non-woven fabric to be plated was obtained according to the same procedure as that employed when producing Example 1 except that a card web having a basis weight of 50 g / m ² consisting of only fiber 2 was used. In addition, the to-be-plated nonwoven fabric of Example 2 was a nonwoven fabric by which the intersection of the fiber was adhere | attached by the gel fixation.
Then, according to the procedure employ | adopted when manufacturing Example 1, nickel plating processing was performed similarly and the nickel plating nonwoven fabric was obtained.

  Moreover, the obtained nickel plating nonwoven fabric was baked and the nickel nonwoven fabric was obtained.

(Example 3)
A non-woven fabric to be plated is prepared according to the same procedure as that employed when manufacturing Example 1 except that a card web containing 70% by mass of fiber 1 and 30% by mass of fiber 3 and having a basis weight of 50 g / m ² is used. Obtained. In addition, the to-be-plated nonwoven fabric of Example 3 was a nonwoven fabric in which the intersection of the fibers was bonded by gel fixation and thermal bonding.
Then, according to the procedure employ | adopted when manufacturing Example 1, nickel plating processing was performed similarly and the nickel plating nonwoven fabric was obtained.

  Moreover, the obtained nickel plating nonwoven fabric was baked and the nickel nonwoven fabric was obtained.

Example 4
A non-woven fabric to be plated was prepared according to the same procedure as that employed when manufacturing Example 1 except that a card web containing 50% by mass of fiber 1 and 50% by mass of fiber 3 and having a basis weight of 50 g / m ² was used. Obtained. In addition, the to-be-plated nonwoven fabric of Example 4 was a nonwoven fabric by which the intersection of the fiber was adhere | attached by gel fixation and heat bonding.
Then, according to the procedure employ | adopted when manufacturing Example 1, nickel plating processing was performed similarly and the nickel plating nonwoven fabric was obtained.

  Moreover, the obtained nickel plating nonwoven fabric was baked and the nickel nonwoven fabric was obtained.

(Example 5)
A non-woven fabric to be plated was prepared according to the same procedure as that employed when manufacturing Example 1 except that a card web containing 20% by mass of fiber 1 and 80% by mass of fiber 3 and having a basis weight of 50 g / m ² was used. Obtained. In addition, the to-be-plated nonwoven fabric of Example 5 was a nonwoven fabric to which the intersection of the fiber was adhere | attached by gel fixation and heat bonding.
Then, according to the procedure employ | adopted when manufacturing Example 1, nickel plating processing was performed similarly and the nickel plating nonwoven fabric was obtained.

  Moreover, the obtained nickel plating nonwoven fabric was baked and the nickel nonwoven fabric was obtained.

(Comparative Example 1)
A nickel-plated nonwoven fabric was obtained according to the same procedure as that used when producing Example 1, except that a card web consisting of only fibers 3 and having a basis weight of 50 g / m ² was used.

  FIG. 2 is an electron microscope (SEM) photograph (magnification 300) of the surface of the nonwoven fabric composed of the obtained plated fibers.

  Moreover, the obtained nickel plating nonwoven fabric was baked and the nickel nonwoven fabric was obtained.

(Comparative Example 2)
A nickel-plated non-woven fabric was obtained according to the same procedure as that employed when producing Example 1 except that a card web consisting of only fibers 4 and having a basis weight of 50 g / m ² was used.

  Moreover, the obtained nickel plating nonwoven fabric was baked and the nickel nonwoven fabric was obtained.

  The conditions and results of Examples 1 to 5 and Comparative Examples 1 and 2 are summarized in Table 1.

  Examples 1-5 are the structures in which the ethylene-vinyl alcohol copolymer is exposed on the fiber surface of the fiber to be plated, and the electrical resistance value after electroless plating and the electrical resistance value after electrolytic plating are comparative examples. Low compared to 1. In the case where a conductive metal is plated on an insulating structure, the electric resistance value is lowered when uniformly plated, and the electric resistance value is increased when there is uneven plating. It can be understood that the metal-plated nonwoven fabric has little plating unevenness. Comparative Example 2 is a structure in which an ester-based resin that is more easily plated than the olefin-based resin is exposed on the fiber surface, and the plating unevenness was slightly good, but the chemical resistance was weak. .

  Example 1 and Example 2 are both nickel-plated nonwoven fabrics in which a sheath component is an ethylene-vinyl alcohol copolymer, and a core component is a core-sheath type composite fiber that is made of only a core-sheath composite fiber, and is subjected to nickel plating. Compared to Example 2, Example 1 has lower electrical resistance values after electroless plating and lower electrical resistance values after electrolytic plating. This is because the fiber 1 has a lower melting point of ethylene-vinyl alcohol and a higher ethylene content than the fiber 2, and in Example 1, the intersection of the fibers of the nonwoven fabric to be plated is bonded to the gel and thermally bonded. In contrast, Example 2 is a nonwoven fabric in which the intersections of the fibers of the nonwoven fabric to be plated are adhered only by gel fixation. As a result, Example 1 is compared with Example 2. Therefore, it is expected that the plating unevenness at the intersection of the fibers is reduced and the electric resistance is lowered.

  The metal plating structures formed by firing the metal plating fiber structures of Examples 1 to 5 and Comparative Examples 1 to 2 had an appropriate air permeability and had a low pressure loss with respect to gas. The metal plating structure which consists of Examples 1-5 had few places where the metal plating peeled off, and its appearance was also good.

  The metal-plated fiber of the present invention has functions such as decoration, deterioration resistance, heat resistance, wear resistance, conductivity, and electromagnetic wave sealing characteristics depending on the metal plated on the fiber to be plated and the plating method. And the metal plating fiber of this invention can be utilized for an accessory, a filter, an electronic component, an electromagnetic wave sealing material, etc.

FIG. 1 is an electron microscope (SEM) photograph (magnification 300) of the surface of a nonwoven fabric composed of the plated fiber obtained in Example 1. FIG. 2 is an electron microscope (SEM) photograph (magnification 300) of the surface of the nonwoven fabric composed of the plated fiber obtained in Comparative Example 1.

Claims (9)

  A metal-plated fiber comprising a fiber structure in which a metal is plated on a fiber surface, wherein the fiber constituting the fiber structure includes a fiber in which an ethylene-vinyl alcohol copolymer is exposed on at least a part of the fiber surface Structure.   The metal-plated fiber structure according to claim 1, wherein the ethylene-vinyl alcohol copolymer has a melting point of 100C to 190C.   The metal which comprises the said fiber structure is a metal plating fiber structure of Claim 1 or 2 containing the core-sheath-type composite fiber whose sheath component is an ethylene-vinyl alcohol copolymer.   The metal-plated fiber structure according to claim 3, wherein the melting point of the core component is 10 ° C. or more higher than the melting point of the sheath component.   The metal plating fiber structure according to claim 3 or 4 in which said core ingredient consists of polypropylene.   The fiber constituting the fiber structure contains 25% by mass or more and 90% by mass or less of the fiber in which the ethylene-vinyl alcohol copolymer is exposed on at least a part of the fiber surface, and the other fiber is 10% by mass or more and 75% by mass. The metal-plated fiber structure according to any one of claims 1 to 5, comprising not more than mass%.   The metal-plated fiber structure according to claim 6, wherein the other fibers are fibers made of a polyolefin-based component.   The metal plated fiber structure according to any one of claims 1 to 7, wherein the metal plated fiber structure is a nonwoven fabric. A metal structure having an air permeability of 1 to ²⁰⁰ cm ³ / cm ² / sec obtained by firing the metal-plated fiber structure according to claim 1.