JP5615562B2 - Continuous plating method for fiber bundles - Google Patents

Description

  The present invention relates to a method for continuously plating a fiber bundle and a continuous plating apparatus.

  Conductive fibers are used in applications such as electromagnetic shielding materials, antistatic materials, and signal lines, and several methods have been proposed as manufacturing methods thereof. Typical examples are kneaded type conductive fibers in which conductive fillers such as carbon particles are mixed into a polymer to form fibers, or plated type conductive fibers in which a metal film is formed on the surface of the fibers using plating. Can be given.

  The kneaded type conductive fibers have a drawback of low electrical conductivity, and are used for limited applications such as antistatic materials. It could not be used for applications that require high electrical conductivity such as electromagnetic shielding materials and signal wires.

  On the other hand, the plating type conductive fiber guarantees conductivity with a metal film, so it is easy to obtain high electrical conductivity, and the electrical conductivity can be controlled by controlling the plating conditions and controlling the amount of deposited metal. There is an advantage that it can be easily performed.

  Several methods have heretofore been proposed as means for obtaining plated type conductive fibers. They can be roughly classified into a method of plating in a state where the fiber bundle is wound up in a cheese shape and a method of performing plating by running the fiber bundle on a reel-to-reel.

  The method of plating in the form of cheese has the advantage that mass production is possible, but it is difficult to uniformly plate, for example, the plating state is different between the inner layer and the outer layer of cheese. In addition, there is a problem that it cannot be applied to electroplating in principle.

  On the other hand, in the method of plating by reel-to-reel, a device for uniformly plating each filament of a fiber bundle composed of a plurality of filaments has been devised. Discloses a method of plating a fiber bundle while repeatedly tightening and loosening it using a fixed guide roller and a movable guide roller, and loosening the fiber bundle.

  Patent Document 2 discloses a method and apparatus for producing metal-coated carbon fiber that suppresses fuzz of carbon fiber, reduces entanglement with a roll, and enables stable continuous electroplating onto carbon fiber.

Japanese Patent No. 3954902 JP 2005-163197 A

  As in Patent Document 1, when the traveling fiber bundle repeats tension and loosening periodically, the deposition state of the plating changes, and plating unevenness occurs. Furthermore, the filaments are tangled when they are in a loose state, resulting in defects such as entanglement between filaments and yarn breakage. The apparatus is also a complicated apparatus such as a mechanism for periodically moving the movable guide roller. Since it is a complicated mechanism, it is predicted that when the traveling speed is increased, it is difficult for the moving mechanism of the movable guide roller to follow the traveling speed of the fiber. Further, if it is intended to improve productivity by processing a plurality of fiber bundles at the same time, it is necessary to prepare a moving mechanism for the movable guide roller for each fiber bundle, which increases the cost.

  In the method and apparatus of Patent Document 2, uniform plating cannot be obtained in the case of a twisted fiber bundle. Moreover, since nonelectroconductive fibers, such as a synthetic fiber, cannot be directly electroplated, it cannot be applied.

The present invention has been made in view of the above points, and the first gist thereof is a passage opening provided in a plating tank in a method of continuously plating a fiber bundle composed of multifilaments. The fiber bundle is further introduced, the fiber bundle is immersed in the plating solution in a state where the plating solution in the plating tank is overflowed from the passage port , and the passage path of the fiber bundle in the plating treatment tank is It is meandering by a pulley disposed in the treatment tank and is substantially in a plane parallel to the plating liquid surface , and the plating liquid is parallel to the traveling direction of the fiber bundle by a rectifying plate disposed in the plating treatment tank. a flow in the forward or reverse direction, continuous plating of the fiber bundle, which comprises plating the tension on the thickness per 1dtex of the fiber bundle as always constant within the 0.005~1.000mN It is a management method.

  The fiber bundle passage path is preferably in the range of 1 to 200 mm below the surface of the plating solution.

  The length of the passage path of the fiber bundle is preferably 0.1 to 50 m.

  It is preferable to perform the plating treatment in a state where the number of twists of the fiber bundle is 0 to 100 times / m.

  According to the present invention, it is possible to obtain conductive fibers in which each filament constituting a fiber bundle is covered with a uniform metal film by a continuous plating apparatus having a very simple structure.

FIG. 1 is a diagram showing an example of a conventional continuous plating method for fiber bundles. FIG. 2 is a diagram showing another example of a conventional method for continuously plating a fiber bundle. FIG. 3 is a diagram showing an example of a continuous plating method for a fiber bundle according to the present invention.

  Hereinafter, the continuous plating method and the continuous plating apparatus of the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, the fiber bundle 3 is introduced into the plating treatment tank 1 from a passage port 21 provided in the plating treatment tank 1. The fiber bundle 3 travels in the plating tank 1 and is taken out from the other passage port 22. At this time, the plating solution in the plating tank 1 is overflowed from the passage ports 21 and 22. By overflowing the plating solution from the passage ports 21 and 22 that also serve as the introduction / extraction port for the fiber bundle 3, the fiber bundle 3 can be surely immersed in the plating solution without being routed in the vertical direction.

  The shape and size of the passage openings 21 and 22 are not particularly limited. What is necessary is just to set suitably based on the thickness etc. of the fiber bundle 3 which performs a plating process. If the passage ports 21 and 22 are small, the level of the plating solution can be maintained at a position higher than the position of the fiber bundle 3 to be passed even if the overflow amount is small, so that the fiber bundle 3 can be surely placed in the plating solution. Can be dipped. Furthermore, since the consumption amount can be reduced by reducing the circulation amount of the plating solution, the manufacturing cost can be reduced. On the other hand, the plating solution concentration changes with the precipitation reaction, but in order to keep the plating solution concentration uniform, it is easier to control the plating solution with a larger circulation amount. Accordingly, the positions, sizes, and shapes of the passage ports 21 and 22 are set so as to obtain an optimum plating solution circulation amount in consideration of the shape of the fiber bundle 3, the target plating thickness, the type of plating metal, and the like. be able to.

  According to the example of the present invention shown in FIG. 1 in which the path of the fiber bundle 3 in the plating tank 1 is linear, unnecessary guide rollers and guide pulleys can be reduced. Generally, when a fiber bundle is brought into contact with a roller or a pulley, the fiber bundle can be damaged. In addition, by using a roller, a pulley, or the like, unnecessary tension is applied to the fiber bundle, resulting in a loss of plating deposition. By taking the path of the fiber bundle in a straight line, it is possible to eliminate rollers, pulleys, and the like and to perform high-quality plating on the fiber bundle. As shown in FIG. 2, parallel processing may be performed by simultaneously immersing a plurality of fiber bundles in the plating solution. With this method, productivity can be improved.

  When it is necessary to ensure a long plating time, the passage route is not linear as described above, but may take a meandering passage route as in another example of the present invention shown in FIG. However, also in this case, the passage of the fiber bundle needs to be substantially parallel to the surface of the plating solution. In the conventional reel-to-reel type continuous plating tank structure, in which rollers and pulleys are arranged in the vertical direction and the fiber bundles are moved up and down between them, the weight of the fiber bundles The tension due to the tension is generated and the fiber bundle is easily tightened. As a result, the tension applied to the fiber bundle in the plating tank is not constant, and uniform plating cannot be performed.

  The depth of the plating tank can be reduced as much as possible by taking the passage path of the fiber bundle substantially parallel to the surface of the plating solution. Therefore, even if a passing path for meandering using a pulley as shown in FIG. 3 is taken, the pulley can have a minimum thickness and can be reduced in weight. If the weight of the pulley can be reduced, variation in tension applied to the fiber bundle can be minimized.

  The tension applied to the fiber bundle immersed in the plating solution in the plating tank is preferably 0.005 to 1.000 mN as the tension per 1 dtex of the fiber bundle thickness. By setting the tension applied to the fiber bundle within this range, the fiber bundle in the plating solution can be appropriately opened. By opening the fiber bundle, the precipitation of plating can be stabilized, and uniform plating can be applied to each filament. When the tension per dtex thickness of the fiber bundle is 1.000 mN or more, the fiber bundle is in a tight state, and the plating solution cannot sufficiently contact each filament, and the plating uniformity is hindered. . In addition, when the tension per 1 dtex of the fiber bundle is less than 0.005 mN, the fiber bundle is too open and the filaments may be entangled with each other, possibly damaging the fiber bundle. There is even a fear.

  The method for controlling the tension applied to the fiber bundle in the plating tank is not particularly limited. For example, an electrical control is preferable in which the tension of the fiber bundle read by the sensor is fed back to the drive roll. As a simple method, a method using a tensor generally used in a yarn processing / weaving machine using a mechanical spring is also effective.

  It is preferable to flow the plating solution in a forward direction or a reverse direction parallel to the traveling direction of the fiber bundle with respect to the fiber bundle passing through the plating treatment tank. By creating such a flow of the plating solution, the degree of fiber bundle opening in the plating solution can be further stabilized. When there is a flow in a direction that is not parallel to the traveling direction of the fiber bundle (for example, a right angle direction), the fiber bundle is unnecessarily opened, and the filaments may be entangled and the fiber bundle may be damaged.

  In the case of the plating tank as shown in FIG. 1 in which the path of the fiber bundle is linear, the plating liquid is supplied into the plating tank by a plating liquid circulation device (not shown), and thus the overflowing passage. Since a flow of the plating solution is generated toward the mouth, it is easy to create a flow of the plating solution in the forward or reverse direction parallel to the traveling direction of the fiber bundle in the plating treatment tank. When the passage of the fiber bundle is meandering by a pulley or the like as shown in FIG. 3, a plating solution rectifying plate is arranged on both sides of the partially bundled fiber bundle, and the circulating plating solution If the supply unit is installed on the upstream side (or downstream side) of the fiber bundle traveling, the flow of the plating solution in the forward or reverse direction parallel to the traveling direction toward the downstream side (or upstream side) of the traveling direction of the fiber bundle. Can produce.

  In the present invention, it is preferable that the passing path of the fiber bundle is in the range of 1 to 200 mm below the surface of the plating solution. By placing the fiber bundle passage route at a depth in this range, the running abnormality can be easily detected with the naked eye or a sensor. Although it varies depending on the prescription of the plating solution, it is difficult to observe the plating object in the plating solution with light when the depth exceeds 200 mm due to the light absorbency of the plating solution. Many of the conventional reel-to-reel type plating tanks have rollers and pulleys arranged in the vertical direction and meandering the fiber bundle between them, so the passage route of the fiber bundle is from the surface of the plating solution. Even if the fiber bundle is in a deep position and an abnormal condition occurs, it is difficult to detect it with the naked eye or a sensor. However, according to the present invention, the running state of the fiber bundle can always be confirmed with the naked eye or a sensor during the plating process of the fiber bundle. If an abnormality occurs in running, it can be easily detected and dealt with promptly.

  Furthermore, in the case of a conventional reel-to-reel type plating tank that has a structure in which rollers and pulleys are arranged in the vertical direction and the fiber bundles meander between them, the upper part of the rollers and pulleys is set as a setting before processing. It was necessary to pass the fiber bundle through the lower part, and the work was complicated. However, according to the present invention, it is only necessary to pass the fiber bundle through the passage opening and, if necessary, the fiber bundle between the pulleys arranged at a shallow position, and the setting operation is very easy.

  In this invention, it is preferable that the length of the passage route of a fiber bundle is 0.1-50 m. Although the amount of precipitation per unit time varies depending on the prescription of the plating solution, the required passage length can be obtained from the desired processing speed. That is, when the processing speed is slow, a sufficient plating deposition amount can be obtained even with a short passage route, and when a high processing speed is desired, a long passage route is required. If the length of the passage route is less than 0.1 m, it is difficult to obtain a sufficient plating deposition amount regardless of the plating solution formulation. Further, if the length of the passage path exceeds 50 m, not only the running state of the fiber bundle becomes unstable, but also the tension applied to the fiber bundle may become too large.

  In the present invention, the plating treatment is preferably performed in a state where the number of twists of the fiber bundle is 0 to 100 times / m. When the number of twists is less than 100 times / m, the fiber bundle immersed in the plating solution can be appropriately opened. If the number of twists exceeds 100 times / m, the fiber bundle may not be sufficiently opened in the plating tank, and a uniform metal film may not be obtained. Even if the number of twists is 100 times / m or more, the present invention can be applied by setting the number of twists to a predetermined number by a known untwisting method immediately before introduction into the plating tank.

  As explained above, during the plating process, a non-twisted or low-twisted state is preferable, but when used as a conductive fiber after the plating process, better performance is obtained by twisting the fiber bundle. It is more preferable. In a non-twisted or low-twisted state, the filaments are likely to come apart and the shape is unstable. However, by twisting, the filaments are gathered and the shape becomes stable. Moreover, the formation of the parallel circuit between the adjacent filaments is promoted by additional twisting, and the electrical conductivity is lowered. Furthermore, it is possible to suppress a decrease in electrical conductivity when the shape changes.

  The fiber material used for the fiber bundle to be plated in the present invention includes polyester (polyethylene terephthalate, polybutylene terephthalate, etc.), polyamide (nylon 6, nylon 66, etc.), aramid, polyolefin (polyethylene, polypropylene, etc.) , Synthetic fibers such as polyacrylonitrile, polyvinyl alcohol and polyurethane, semi-synthetic fibers such as cellulose (diacetate, triacetate, etc.), protein (promix, etc.), cellulose (rayon, cupra, etc.), protein Examples thereof include regenerated fibers such as casein fibers. Of these, synthetic fibers are preferred in view of stability to chemicals during processing, strength as conductive fibers, and the like.

  In the present invention, a fiber bundle using the filament yarn made of the fiber material can be continuously plated. At that time, the filament yarns made of the above-mentioned fiber materials can be arranged alone to make a fiber bundle, or the filament yarns made of two or more kinds of fiber materials can be mixed to make a single fiber bundle. The shape and fineness of the fiber bundle, the number of filaments, and the presence or absence of incidental processing such as Woolley processing are not particularly limited.

  The present invention can be applied to both electroplating and electroless plating. Except for some materials such as carbon fiber, the fiber bundle is generally non-conductive, so electroless plating needs to be performed as the first step. In order to perform electroless plating, it is necessary to apply a plating catalyst serving as a nucleus thereof. In the present invention, a known plating catalyst applying method can be used as a pretreatment.

  The plating prescription is not particularly limited, and a known wet plating prescription can be used. That is, chemical plating such as electroplating and electroless plating, displacement plating, and the like can be used.

  Examples of the plating metal forming the metal film include gold, silver, copper, zinc, nickel, and alloys thereof, but copper and nickel are preferable in consideration of conductivity and manufacturing cost. The film formed of these metals is preferably one layer or two layers. When the metal film is laminated in two layers, the same kind of metal may be laminated in two layers, or different metals may be laminated. These may be appropriately set in consideration of required conductivity and durability.

  The present invention is effective not only for plating a fiber bundle, but also for pre-treatment and post-treatment thereof. Many of the pre-treatment and post-treatment of plating, such as primer application, conditioning, catalyzing, and acceleration, which are performed before electroless plating, can be applied by changing the plating solution to a predetermined processing solution. This is because, in the pre-processing and post-processing, it is the point of these processes to immerse the processing liquid in each filament of the fiber bundle.

EXAMPLES Hereinafter, although an Example of this invention is given and this invention is demonstrated concretely, this invention is not limited by a following example.

[Tape peeling test]
Nitto Denko Corporation Packaging Adhesive Tape No. 3305 is affixed to the sample, and after pressing 10 strokes of a metal roller with a mass of 2 kg, a diameter of 120 mm, and a circumferential width of 25 mm from the top, the adhesive tape is slowly peeled off at an angle of 120 ° with respect to the adhesive surface. The amount of plating metal adhering to the subsequent adhesive tape surface is confirmed with the naked eye.
○: No peeling at all Δ: No peeling is observed, but the metal surface is slightly damaged ×: There is peeling, and the surface of the fiber bundle is exposed

[ Reference Example 1]
As the fiber bundle, an aramid fiber bundle having a thickness of 1670 dtex and 1000 filaments was used. The number of twists was 2 to 3 times / m. For the pretreatment, a catalyst application formulation using a palladium-tin colloid, which is a known electroless plating pretreatment method, was used. Electroless copper plating solution is composed of 9 g / L of copper chloride dihydrate, 20 g / L of chelating agent, 30 mL / L of sodium hydroxide (32%), 9 mL / L of formalin (37%), and a small amount of surfactant. The stabilizer was dissolved in ion-exchanged water and used at a liquid temperature of 50 ° C. A plating tank having a length of 3 m, a depth of 30 cm, and a depth of 5 cm was used. Only one fiber bundle was run in a straight line. The passage port had a rectangular shape with a width of 1 cm and a height of 2 cm, and the plating solution overflowed from the passage port during processing. The passing path of the fiber bundle was 3 m, and the processing speed was 35 m / h. When the tension applied to the fiber bundle was measured, it was 0.030 mN per 1 dtex of the fiber bundle thickness. Electroless copper plating was performed under the above conditions to obtain conductive fibers. When the metal layer of the obtained conductive fiber was dissolved with an acid and the amount of metal was measured by an atomic absorption method, 112 mg / m of copper was given to the aramid fiber bundle. Moreover, it was 3.0 ohm / m when the electrical resistance value of the fiber bundle was measured. When the plating adhesion of the sample after electroless copper plating was evaluated by a tape peeling test, it did not peel and showed good adhesion.

[Example 1 ]
A conductive fiber was obtained in the same manner as in Reference Example 1 except that a pulley was arranged in the plating tank to make the fiber bundle meander running for 11 turns, the passage route was 30 m, and the processing speed was 90 m / h. The tension applied to the fiber bundle was 0.036 mN per 1 dtex of the fiber bundle thickness. About the obtained electroconductive fiber, the provision amount of copper was 500 mg / m, and the electrical resistance value was 0.6 ohm / m. In the evaluation by the tape peeling test, the plated metal did not peel and showed good adhesion.

[Example 2 ]
Conductive fibers were obtained in the same manner as in Example 1 except that PET fibers having a thickness of 1100 dtex and 192 filaments were used as the fiber bundle, and the processing speed was 300 m / h. The tension applied per 1 dtex thickness of the fiber bundle was 0.055 mN. About the obtained conductive fibers, the applied amount of copper is 70 mg / m, the electrical resistance value is 5.0 Ω / m, and the evaluation by the tape peeling test shows that the metal surface is slightly cracked but does not peel off. Showed good adhesion.

[Example 3 ]
Conductive fibers were obtained in the same manner as in Example 1 except that PET fibers subjected to Woolen processing having a thickness of 500 dtex and 144 filaments were used as the fiber bundle, and the processing speed was 100 m / h. The tension applied per 1 dtex thickness of the fiber bundle was 0.030 mN. About the obtained electroconductive fiber, the provision amount of copper was 100 mg / m, and the electrical resistance value was 2.0 Ω / m. In the evaluation by the tape peeling test, the plated metal did not peel and showed good adhesion.

[ Reference Example 2 ]
Conductive fibers were obtained in the same manner as in Reference Example 1 except that the processing speed was 18 m / h and the tension applied per 1 dtex thickness of the fiber bundle was 0.599 mN. With respect to the obtained conductive fiber, the applied amount of copper was 210 mg / m, and the electric resistance value was 4.0 Ω / m. Evaluation by the tape peeling test showed good adhesion without peeling, although there was a slight crack on the metal surface.

[ Reference Example 3 ]
Conductive fibers were obtained in the same manner as in Reference Example 1 except that an electroless nickel plating solution was used instead of the electroless copper plating solution and the processing speed was 9 m / h. An electroless nickel plating solution is prepared by dissolving nickel sulfate hexahydrate 18 g / L, chelating agent 20 g / L, sodium hypophosphite monohydrate 15 g / L, and an appropriate amount of pH adjuster in ion-exchanged water. The temperature was used as 50 ° C. The tension applied per 1 dtex thickness of the fiber bundle was 0.030 mN. About the obtained conductive fiber, the provision amount of nickel was 130 mg / m, and the electrical resistance value was 30 Ω / m. In the evaluation by the tape peeling test, the plated metal did not peel and showed good adhesion.

[Comparative Example 1]
Conductive fibers were obtained in the same manner as in Example 1 without supplying the plating solution and without causing the plating solution to overflow from the passage port of the plating tank. During processing, the fiber bundle was running while contacting or leaving the surface of the plating solution. The obtained conductive fiber has a copper application amount of 60 mg / m and an electrical resistance value of 110 Ω / m, and the application state of the plated metal is not uniform, and the metal is not applied to the part of the filament and the fiber. The part where was exposed was seen. Moreover, in the evaluation by a tape peeling test, the uneven plating metal peeled and the adhesiveness was poor.

The evaluation results of Examples and Comparative Examples are shown in Table 1.

DESCRIPTION OF SYMBOLS 1 Plating tank 21, 22 Passage port 3 Fiber bundle 5 Pulley 6 Current plate

Claims (4)

In a method of continuously plating a fiber bundle composed of multifilaments, a state in which the fiber bundle is introduced from a passage opening provided in a plating treatment tank, and a plating solution in the plating treatment tank is overflowed from the passage opening The fiber bundle is immersed in a plating solution , and the passage of the fiber bundle in the plating tank is meandered by a pulley disposed in the plating tank, and is substantially parallel to the plating liquid surface. The plating solution is flowed in a forward direction or a reverse direction parallel to the traveling direction of the fiber bundle by a rectifying plate disposed in the plating treatment tank, and a tension applied per 1 dtex thickness of the fiber bundle is reduced to 0. A continuous plating treatment method for fiber bundles, characterized in that the plating treatment is performed at a constant rate within a range of 0.005 to 1.000 mN . 2. The fiber bundle continuous plating method according to claim 1 , wherein the passing path of the fiber bundle is in the range of 1 to 200 mm below the surface of the plating solution. The length of the passage route of this fiber bundle is 0.1-50 m, The continuous plating processing method of the fiber bundle of any one of Claim 1 or 2 characterized by the above-mentioned. The continuous plating treatment method for a fiber bundle according to any one of claims 1 to 3 , wherein the plating treatment is performed in a state where the number of twists of the fiber bundle is 0 to 100 times / m.