TW202210671A - Electroconductive fiber, clothing including electroconductive fiber, and electrical/electronic instrument including electroconductive fiber - Google Patents

Abstract

The present invention provides: an electroconductive fiber that, in addition to high electroconductivity, electrical characteristic stability under deformation, etc., has superior flexibility and in particular is suitable for incorporating into a fabric such as a smart textile; and clothing or an electrical/electronic instrument in which said fiber is used. This electroconductive fiber has an average number of crimps of at least 2/cm, has a metal layer on the fiber surface, and has a volume resistivity of 2 * 10-6 to 1 * 10-2 [Omega].cm, and furthermore has a total fineness of 10-1000 dtex.

Description

Conductive fibers, quilts containing conductive fibers, and electrical and electronic machines containing conductive fibers

The present invention relates to conductive fibers particularly suitable for assembling in fabrics such as smart textiles, and quilts or electrical and electronic equipment using the same.

In recent years, demand for smart textiles that incorporate electronic components such as various devices, sensors, and IC chips into textiles such as knitted and knitted fabrics has been increasing. These smart textiles are self-designed to suit the purpose, from sports use to medical use, and are therefore expected to be worn in various occasions.

In smart textiles assembled with these electronic parts, electrical wirings with low resistance values are required for electrical power transmission from device driving sources and electrical signals from sensors. When ordinary copper wire is used for the electrical wiring, although it exhibits sufficient electrical conductivity for power transmission and signal transmission, it cannot follow deformation such as bending and expansion of textiles, and there is a problem that discomfort occurs when assembling to a quilt.

From such a background, various techniques for imparting electrical stability and flexibility against deformation to conductive fibers have been reviewed. For example, it is proposed to form a stretchable conductive fiber having a conductive layer made of copper iodide (see Patent Document 1) or a conductive fiber in the shape of a spring in the vicinity of the inner portion of the surface side of the stretchable fiber using an elastic body to impart high stretchability, thereby becoming a highly stretchable conductive wiring technology excellent in durability (refer to Non-Patent Document 1).

Furthermore, a method of imparting electrical conductivity to crimped synthetic fibers is proposed as follows: a carbon black-containing conductive layer and a fiber-forming non-conductive layer are formed into a side-to-side or eccentric core-sheath compound, and the fibers are laminated. A composite fiber having a conductive layer formed on at least a part of the surface (refer to Patent Document 2) or the like.

Furthermore, another technique for forming a metal layer on fibers to impart functionality has been proposed: an electromagnetic wave shielding sheet including a metal layer adhered to fibers constituting a non-woven fabric, and the non-woven fabric includes crimped fibers and a solidified portion of the fibers (refer to the patent). Reference 3). [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2010-209481 [Patent Document 2] Japanese Patent Laid-Open No. 2009-46785 [Patent Document 3] Japanese Patent Laid-Open No. 2020-17615 [Non-patent literature]

[Non-Patent Document 1] [online], February 25, 2015, National Research and Development Corporation Industrial Technology Research Institute, retrieved June 29, 2020, URL < URL: https://www.aist.go. jp/aist_j/press_release/pr2015/pr20150225/pr20150225.html>

(The problem that the invention intends to solve)

In the technique of Patent Document 1, a conductive fiber having stretchability and stable electrical properties is obtained by imparting conductivity to the sheath portion of a core-sheath composite fiber using two different types of elastomers. However, since the technique of Patent Document 1 uses an elastic body, the fiber diameter of the obtained fiber becomes substantially larger, and the elastic behavior peculiar to the elastic body causes a rebound force at the bent or elongated part, so that the conductive fibers are assembled in the The problem of uncomfortable feeling occurs when the quilt is worn.

The technique of Non-Patent Document 1 obtains conductive fibers excellent in stretchability and durability by forming conductive fibers into a spring shape. However, since the outer diameter of the fiber bundles that form the spring shape is relatively large, and the elastic behavior of the spring-shaped structure causes a rebound force in the bent portion and the elongated portion, there is a problem that uncomfortable feeling occurs when the conductive fibers are assembled to the quilt. .

In the technique of Patent Document 2, a conductive fiber excellent in stretchability can be obtained by forming a crimped fiber as a conductive layer containing carbon black. However, the volume resistance value of the obtained fibers is as high as 1×10 ^-1 Ω·cm or more, and the conductivity is insufficient when used for electrical power transmission or signal transmission from sensors, and the conductivity is easily reduced by the dispersibility of carbon black. The unevenness of the values is so severe that the stability of the electrical characteristics cannot be sufficiently ensured.

The technical system of Patent Document 3 proposes an electromagnetic wave shielding sheet in which a metal layer is adhered to a nonwoven fabric. However, when the non-woven fabric is cut and used for electrical wiring, in order to obtain sufficient electrical conductivity, a larger area of the conductive layer is required than that of the conductive fiber, or it is difficult to weave or weave into the fabric due to its non-woven shape. Therefore, it is not suitable for electrical wiring for smart textiles.

The reason is, the object of the present invention is accomplished in view of the above-mentioned facts, and it provides a conductive fiber having high electrical conductivity, stability of electrical properties against deformation, and excellent flexibility, and is particularly suitable for assembling in fabrics such as smart textiles, etc., and use its quilt or electrical and electronic equipment. (Technical means to solve problems)

As a result of the review by the inventors of the present application, it was confirmed that as a conductive fiber used for electrical power transmission or signal transmission from a sensor in a smart textile incorporating electronic components, the main point is that it has high electrical conductivity or stable electrical characteristics against deformation. In addition to flexibility, there is a need for excellent softness that can follow the movement of textiles without discomfort.

Therefore, the inventors of the present application conducted intensive research in order to achieve the above-mentioned properties, and found that, by disposing a metal layer on the surface of a fiber with a specific number of crimps, by setting the volume resistivity and the total fineness within a specific range, in addition to the deformation tracking In addition to the stability of properties and electrical properties, it also showed excellent softness that does not cause discomfort even when assembled to a textile, and the present invention was completed.

The present invention is to solve the above-mentioned problems. The conductive fibers of the present invention have an average number of crimps of 2 pieces/cm or more, a metal layer is provided on the surface of the fibers, and a volume resistivity of 2 × 10 ^-6 to 1 × 10 ^-2 Ω・cm, the total fineness is 10~1000dtex.

According to a preferred aspect of the conductive fiber of the present invention, the average single fiber diameter is 5-20 μm.

A preferred aspect of the conductive fiber according to the present invention is composed of long fibers.

According to a preferred aspect of the conductive fiber of the present invention, the volume resistivity when the fiber is elongated by 10% in the direction of the fiber axis is 2×10 ^-6 to 1×10 ^-2 Ω·cm.

According to a preferred aspect of the conductive fiber of the present invention, the crimped shape is a three-dimensional coil shape.

Furthermore, the clothing or electrical and electronic equipment of the present invention is constituted by at least a part of the above-mentioned conductive fibers. (Compared to the efficacy of the prior art)

According to the present invention, in addition to having high electrical conductivity and stability of electrical properties against deformation, it is possible to obtain a conductive fiber with excellent flexibility, which is particularly suitable for assembling in fabrics such as smart textiles, and quilts or electrical and electronic equipment using the same. .

The conductive fiber of the present invention has an average crimp number of 2 pieces/cm or more, a metal layer is provided on the fiber surface, a volume resistivity of 2×10 ^-6 to 1×10 ^-2 Ω·cm, and a total fineness of 10 ~1000dtex. Hereinafter, the constituent requirements will be described in detail, but the present invention is not limited to the scope described below without departing from the gist.

[conductive fiber] In the conductive fiber of the present invention, the portion other than the metal layer is preferably composed of a thermoplastic polymer. Since the part other than the metal layer is made of a thermoplastic polymer, it can be easily formed into a fiber shape by a melt spinning method, and it becomes a conductive fiber having a uniform shape in the fiber axis direction.

Examples of thermoplastic polymers used in the conductive fibers of the present invention include "polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polypara Polyester-based polymers such as hexamethylene phthalate and their copolymers; "polylactic acid, polyethylene succinate, polybutylene succinate, polybutylene succinate adipate, polyhydroxybutyl aliphatic polyester-based polymers such as ester-polyvalerate copolymer, polycaprolactone" and their copolymers; "polyamide 6, polyamide 66, polyamide 610, polyamide 10, Aliphatic polyamide-based polymers such as polyamide 12, polyamide 6-12" and their copolymers; polyolefin-based polymers such as "polypropylene, polyethylene, polybutene, polymethylpentene" and Its copolymers; water-insoluble ethylene-vinyl alcohol copolymer system polymers containing ethylene units of 25 mol% to 70 mol%, polystyrene series, polydiene series, chlorine series, polyolefin series, polyester series, Elastomeric polymers such as polyurethane-based, polyamide-based, and fluorine-based polymers can be selected from these. Among them, polyester-based polymers and copolymers thereof are preferably used from the viewpoints of easier metal layer formation by metal plating or the like and less occurrence of metal layer peeling.

The conductive fibers of the present invention may also contain inorganic substances such as titanium oxide, silicon dioxide, barium oxide, etc.; colorants such as carbon black, dyes, pigments, etc.; agents, optical brighteners, antioxidants, or various additives such as UV absorbers.

The conductive fiber of the present invention may be a composite fiber in which two or more kinds of polymers are combined in addition to a single component fiber. In the case of the above-mentioned conductive fibers being conjugated fibers, for example, core-sheath type, sea-island type, side-to-side type, eccentric core-sheath type, etc. are mentioned, and it is preferable that the fibers exhibit a three-dimensional coil shape (spiral shape) by combining polymers. The crimped type is a side-to-side or eccentric core-sheath type in a composite form. When the side-to-side type is used as the composite form, the preferred examples of polymer combinations are: Combinations of different types of polyester-based polymers such as ethylene terephthalate and polybutylene terephthalate. In addition, in the case of using an eccentric core-sheath type as the composite form, in addition to the above-mentioned side-to-side type combination, for example, a combination of a polyester-based polymer and a polyurethane-based polymer, or a polymer A combination of an amide-based polymer and a polyurethane-based polymer, etc.

The important point of the conductive fiber of the present invention is that the average number of crimps is 2 pieces/cm or more. By setting the average number of crimps to be 2 pieces/cm or more, preferably 3 pieces/cm or more, and more preferably 4 pieces/cm or more, the 10% modulus of the conductive fibers tends to be lowered, so that the flexibility is improved. In addition, the upper limit of the average number of crimps in the present invention is not particularly limited, and the substantial upper limit is about 60 pieces/cm.

In addition, the average crimp coefficient of this invention can be calculated|required as follows. (1) The single fiber taken out from the multifilament was placed on a sample table in a state of no load, and a single fiber image of 1 cm was photographed with a microscope. (2) The number of ridges and valleys of the fiber is counted from the captured image, and the total number of ridges and valleys is divided by 2 to obtain the number of crimps. (3) The above-mentioned measurement was set as one level, and the single fiber was changed and carried out five times, and the arithmetic mean value was set as the average number of crimps.

The crimped shape of the conductive fiber of the present invention can be set to crimped shapes such as sawtooth shape, three-dimensional coil shape, and combinations thereof, among which three-dimensional coil shape is preferable. Since the crimping shape of the conductive fiber is in the shape of a three-dimensional coil, it can improve the followability of the expansion and contraction in the direction of the fiber axis and complex movements, so it can be applied to textiles such as quilts.

The key point of the conductive fiber of the present invention is that a metal layer is provided on the surface of the fiber. Since the surface of the fiber is provided with a metal layer, the volume resistivity of the conductive fiber can be reduced, and sufficient conductivity can be obtained during power transmission and signal transmission.

The metal layer on the fiber surface of the conductive fiber of the present invention is not particularly limited on the premise that the conductive properties of the present invention can be satisfied, and it is preferably formed by copper plating and/or silver plating. Since the metal layer on the fiber surface is formed by copper plating and/or silver plating, in addition to reducing the volume resistivity of the conductive fiber, the metal layer can also be uniformly formed on the fiber surface, so that the conductivity and fiber axis can be improved. Directional uniformity. In addition, when the metal layer on the fiber surface is formed only by copper plating, the electrical conductivity is lowered (the volume resistivity is increased), but the cost can be reduced as compared with the case where the metal layer is formed only by silver plating.

The key point of the conductive fiber of the present invention is that the volume resistivity is 2×10 ^-6 to 1×10 ^-2 Ω·cm. By setting the volume resistivity to 2 × 10 ^-6 Ω·cm or more, preferably 1 × 10 ^-5 Ω·cm or more, the proportion of the metal layer in the fiber cross section can be substantially reduced, so that it can be improved. Mechanical properties such as strength. In addition, by setting the volume resistivity to 1×10 ^-2 Ω·cm or less, preferably 1×10 ^-3 Ω·cm or less, sufficient electrical conductivity can be obtained during power transmission or signal transmission.

In addition, the volume resistivity of this invention is calculated|required as follows. (1) A conductive fiber having a length of 10 cm was kept at a temperature of 25° C. and a humidity of 65% RH for 1 hour or more. (2) Install the conductive fiber without applying tension in such a manner that it is connected to the probe connected to the insulation resistance meter and formed of two bar terminals with a distance of 5 cm between the terminals. (3) The resistance value (Ω) was measured at an applied voltage of 100 V, and the obtained resistance value was divided by the probe distance of 5 cm, and then the value obtained by multiplying the cross-sectional area A (cm ² ) of the conductive fiber to be measured by the method described later was obtained. . (4) The above-mentioned measurement was set to one level, and the measurement location was changed and performed 5 times, and the arithmetic mean value was set as the volume resistivity (Ω·cm).

Here, in the present invention, when the conductive fiber is a monofilament, it refers to the volume resistivity of a single monofilament; when the conductive fiber is a multifilament, it refers to the volume resistivity of the entire multifilament. That is, in the case of a multifilament, the total of the cross-sectional areas A (cm ² ) of all the single fibers constituting the multi-filament corresponds to the cross-sectional area A (cm ² ) of the above (3).

The volume resistivity when the conductive fiber of the present invention is elongated by 10% in the direction of the fiber axis is preferably 2×10 ^-6 to 1×10 ^-2 Ω·cm. By setting the volume resistivity at 10% elongation in the fiber axis direction to preferably 2 × 10 ^-6 Ω·cm or more, more preferably 1 × 10 ^-5 Ω·cm or more, the volume resistivity remains high even at the time of elongation and deformation. It will not change excessively, so it becomes a conductive fiber with stable volume resistivity to deformation. In addition, by setting the volume resistivity at 10% elongation in the fiber axis direction to preferably 1×10 ^-2 Ω·cm or less, more preferably 1×10 ^-3 Ω·cm or less, the volume due to elongation deformation is prevented from being caused. If the resistivity is excessively increased, even if it is assembled into a textile and given a complicated operation, sufficient electrical conductivity can always be obtained during power transmission and signal transmission, so it becomes a conductive fiber with excellent electrical stability against deformation.

In addition, the "volume resistivity when the fiber axis is extended by 10%" in the present invention means that when measuring the volume resistivity, the conductive fiber is extended by 10% from the unloaded state, and then attached to the probe seeker.

The key point of the conductive fiber of the present invention is that the total fineness is 10-1000 dtex. By setting the total fineness to 10dtex or more, preferably 20dtex or more, more preferably 30dtex or more, in addition to achieving a sufficiently low resistance value in power transmission and signal transmission, the breaking strength of the fiber can be improved, so it can be used as a post-processing product. Conductive fibers with excellent properties and durability. Furthermore, by setting the total fineness to be 1000 dtex or less, preferably 800 dtex or less, and more preferably 500 dtex or less, the conductive fibers are excellent in wearing comfort without feeling uncomfortable even when assembled in textiles such as quilts.

In addition, the "total fineness" in the present invention refers to the calculation of the total fineness (dtex) by winding the conductive fiber around 100m of skein, multiplying the skein mass by 100, and measuring 5 times for one level, and calculating the arithmetic average of the skeins. worth seeking. When the conductive fiber is shorter than 100m, or the skein cannot be wound, the length (m) and mass (g) of the conductive fiber can also be measured, and the total amount of the conductive fiber can be calculated by using the mass (g)÷length (m)×10000 Fineness (dtex).

The average single fiber diameter of the conductive fibers of the present invention is preferably 5 to 20 μm. By setting the average single fiber diameter to be preferably 5 μm or more, more preferably 6 μm or more, and particularly preferably 7 μm or more, the strength of the single fiber can be increased, so the breakage caused by rubbing such as friction can be reduced, and it has high durability. Sexually conductive fibers. In addition, by setting the average single fiber diameter to preferably 20 μm or less, more preferably 18 μm or less, and particularly preferably 16 μm or less, it can easily follow deformation such as bending and become soft fibers, so even if it is assembled in textiles such as quilts, there is no discomfort. It becomes a conductive fiber with excellent wearing comfort.

In addition, the average single fiber diameter of this invention is calculated|required as follows. (1) The single fiber taken out from the multifilament is cut in the direction perpendicular to the fiber axis, and a scanning electron microscope is used to capture an image at a magnification at which the entire cross section of the single fiber can be observed. (2) Using the image analysis software, the cross-sectional area A formed by the cross-sectional profile of the single fiber is measured for the captured image, and the diameter (μm) of a perfect circle having the same area as the cross-sectional area A is calculated. (3) It is implemented with respect to all the single fibers constituting the multifilament, and the arithmetic mean value thereof is taken as the average single fiber diameter (μm).

When the conductive fiber of the present invention uses an eccentric core-sheath type as the composite form, the eccentricity of the single fiber cross section is preferably 0.05 to 0.80. When the eccentricity is preferably 0.05 or more, more preferably 0.10 or more, and particularly preferably 0.15 or more, the average number of crimps increases, so that the flexibility can be improved, and the conductive fiber having excellent electrical stability against deformation can be obtained. In addition, by setting the eccentricity to preferably 0.80 or less, more preferably 0.65 or less, and particularly preferably 0.50 or less, the cross-sectional formability in the spinning step is improved, so that there are few defects such as thread breakage, and a conductive fiber excellent in process stability can be obtained .

In addition, the eccentricity of this invention is calculated|required as follows. (1) The single fiber taken out from the multifilament is cut in the direction perpendicular to the fiber axis, and a scanning electron microscope is used to capture an image at a magnification at which the entire cross section of the single fiber can be observed. (2) Using image analysis software, the center of gravity a obtained from the entire cross-section of the conjugate fiber and the center of gravity b obtained from the cross-section of only the core component were calculated from the captured image, and the eccentricity was calculated from the following formula. Eccentricity = (the distance between the center of gravity a and the center of gravity b) / (1/2 × average single fiber diameter)

The conductive fibers of the present invention can be in any shape, such as twisted yarns composed of long fibers or short fibers, and among them, the conductive fibers are preferably composed of long fibers. Since the conductive fiber is composed of long fibers, unevenness in conductivity can be reduced, so that it can be a conductive fiber with stable volume resistivity in the fiber axis direction, high productivity, and excellent mechanical properties.

The breaking strength of the conductive fiber of the present invention is preferably 1.5 cN/dtex or more. By setting the breaking strength to be preferably 1.5 cN/dtex or more, more preferably 2.0 cN/dtex or more, it is possible to reduce the occurrence of thread breakage in post-processing steps such as weaving, so that it can be a conductive fiber with excellent step stability. On the other hand, the upper limit of the breaking strength of the present invention is not particularly limited, and the substantial upper limit is about 10.0 cN/dtex.

In addition, the breaking strength of the present invention is based on the tensile strength and elongation described in JIS L 1013:2010 8.5, and the conductive fiber is attached without applying tension, and the sample length is 200 mm and the tensile speed is 200 mm/min. The strength at break (cN) was divided by the total fineness (dtex) to calculate the strength (cN/dtex), and five measurements were performed for one level, and the arithmetic mean was obtained.

The elongation at break of the conductive fiber of the present invention is preferably 15-200%. By setting the elongation at break to be preferably 15% or more, more preferably 20% or more, and particularly preferably 30% or more, the occurrence of wire breakage in the post-processing step can be reduced, so that it can be a conductive fiber with excellent step stability. In addition, by setting the elongation at break to preferably be 200% or less, more preferably 180% or less, and particularly preferably 160% or less, plastic deformation does not easily occur during fiber elongation, so that a conductive fiber excellent in durability can be obtained.

In addition, the elongation at break of the present invention is based on the tensile strength and elongation described in JIS L 1013:2010 8.5, and the conductive fiber is attached under no tension, and the sample length is 200 mm and the tensile speed is 200 mm/min under the conditions of 200 mm/min. The elongation (%) at break was measured, and the measurement was performed 5 times for one level, and was obtained from the arithmetic mean.

The 10% modulus of the conductive fiber of the present invention is preferably 1.50 cN/dtex or less. By setting the 10% modulus to be preferably 1.50cN/dtex or less, more preferably 1.00cN/dtex or less, and particularly preferably 0.50cN/dtex or less, the stress generated by deformation can be reduced, so it can be excellent in flexibility. of conductive fibers. On the other hand, the lower limit of the 10% modulus in the present invention is not particularly limited, and the substantial lower limit is 0.00 cN/dtex.

In addition, the 10% modulus of the present invention is based on the tensile strength and elongation ratio described in JIS L 1013:2010 8.5, and the conductive fiber is attached without applying tension, and the sample length is 200 mm and the tensile speed is 200 mm/min under conditions of 200 mm/min. The stress (cN/dtex) at an elongation of 10% was measured, and the measurement was performed 5 times for one level, and the arithmetic mean value was obtained.

The conductive fibers of the present invention have excellent flexibility in addition to high electrical conductivity and stability of electrical properties against deformation, and thus can be used as antistatic materials such as stockings, tights, dustproofing Clothing and other fabrics; textiles such as curtains; or carpets, mats, floor boards, etc. laid indoors and outdoors, vehicles, etc., especially suitable for electrical power transmission as a driving source for devices assembled on fabrics, or electrical signals from sensors. etc. Smart Textiles. In addition, in the field of electrical and electronic equipment, by assembling the conductive fiber of the present invention in a part that needs to be stretched and bent, it can also be applied to electric power transmission, transmission of electric signals from sensors, and the like.

[quilt] At least a part of the quilt system of the present invention is composed of the conductive fiber of the present invention. By containing at least a part of the conductive fiber of the present invention, it becomes a quilt which is excellent in comfort without discomfort during wearing.

The quilt of the present invention is used to partially or completely cover the body and wear, and includes not only clothes such as tops, bottoms, kimonos, and overcoats, but also hats, handbags, socks, and the like. Among them, the conductive fibers of the present invention, such as high conductivity, electrical stability against deformation, and softness, can be fully utilized by applying to smart textile quilts incorporating electronic components such as various devices, sensors, and IC chips. characteristics, so it is better.

For example, when the conductive fiber of the present invention is applied to smart textiles, the high flexibility caused by crimping will not hinder the movement of the human body, and by setting the total fineness within a specific range, it can be worn without discomfort. , Smart textiles with excellent wearing comfort. In addition, the conductive fibers of the present invention have lower volume resistivity than fibers containing carbon black, so in addition to the electrical power transmission of the device driving source or the transmission of electrical signals from the sensor, the deformation resistance is reduced. The electrical characteristics are also excellent in stability. Therefore, the conductive fibers of the present invention can be applied to smart textiles for various purposes.

In the quilt system of the present invention, when the conductive fibers are used for electric power transmission, an insulating material may be coated on the portion where the conductive fibers are arranged. It is preferable that the part where the conductive fibers are arranged is covered with an insulating material, so that electric shock and the like can be prevented.

[Electrical and Electronic Equipment] The electrical and electronic equipment of the present invention is composed of at least a part of the conductive fiber of the present invention. By containing at least a part of the conductive fiber of the present invention, it is possible to smoothly perform operations such as expansion and contraction and bending, and an electrical apparatus or electronic apparatus having excellent electrical stability against deformation can be obtained.

The conductive fiber system of the present invention is excellent in electrical property stability against deformation, in addition to electrical power transmission and electrical signal transmission from a sensor. Therefore, the conductive fiber of the present invention can be applied to electrical and electronic equipment for various applications requiring actions such as expansion and contraction and bending.

In the electrical and electronic equipment of the present invention, when the conductive fiber is used for electric power transmission, the portion where the conductive fiber is arranged may be coated with an insulating material. It is preferable that the part where the conductive fibers are arranged is covered with an insulating material, so that electric shock and the like can be prevented.

[Manufacturing method of conductive fiber, quilt and electrical and electronic equipment] Next, a preferred aspect for producing the conductive fiber of the present invention will be specifically described.

The method for producing the conductive fiber of the present invention can be selected from solution spinning, melt spinning, and the like, but from the viewpoint of low environmental load and easy production, the melt spinning method is preferably used.

The thermoplastic polymer used in the present invention is preferably dried before being used for spinning for the purpose of preventing the mixing of water and removing oligomers, so that the spinnability can be improved. The drying conditions are usually vacuum drying at 80 to 200° C. for 1 to 24 hours.

As the melt spinning system, for example, a melt spinning method using an extruder such as a pressurized metal type, a uniaxial, or a biaxial extruder can be adopted. The extruded thermoplastic polymer is measured by a metering device such as a gear pump through a pipe, and after passing through a filter for removing foreign matter, it is guided to a spinneret and discharged. In addition, when the fiber is a composite fiber, each thermoplastic polymer is guided to a spinneret from its own pipe, merged in the spinneret, and the shape is standardized to a side-to-side type, an eccentric core-sheath type, or the like. , spit out into composite fibers. The conjugated fiber thus obtained becomes a fiber having a three-dimensional coil shape by supplying it to a drawing step to be described later.

When polyester or polyamide is used as the thermoplastic polymer, the temperature (spinning temperature) from the polymer piping to the spinneret is preferably set to the melting point of the thermoplastic polymer above in order to improve fluidity + 20°C or higher, and in order to suppress thermal decomposition of the thermoplastic polymer, preferably 320°C or lower.

The spinneret used in the discharge is preferably set to the diameter D of the spinneret hole to be 0.1 mm or more and 0.6mm or less, and also, according to the length of the flow path of the spinneret hole L (the same size as the diameter of the spinneret hole diameter) L/D defined by the quotient of the length of the pipe portion) divided by the hole diameter is 1 or more and 10 or less.

The fibers discharged from the spinning nozzle holes are cooled and solidified by being blown against cooling air (air). The temperature of the cooling air can be determined in balance with the cooling air velocity from the viewpoint of cooling efficiency, and is preferably 30° C. or lower. By setting the cooling air temperature to preferably 30° C. or lower, the solidification behavior by cooling can be stabilized, and a conductive fiber with high fiber diameter uniformity can be obtained.

Furthermore, it is preferable that the cooling air flows in the substantially vertical direction of the unstretched fibers discharged from the spinning nozzle. At this time, the speed of the cooling air is preferably 10 m/min or more from the viewpoints of cooling efficiency and fiber diameter uniformity, and preferably 100 m/min or less from the viewpoint of spinning stability. In addition, by cooling the fiber using a thermoplastic polymer having a large specific heat capacity, or a hollow fiber, etc., by setting the blowing direction of the cooling air to a single direction, it is possible to obtain a degree of molecular alignment in the fiber cross-sectional direction. Poor undrawn fibers can also be obtained with crimps by subjecting the undrawn fibers to the drawing step described later.

The cooled and solidified undrawn fibers are drawn by means of rolls (goetes) that rotate at a constant speed. In order to improve the uniformity of fiber diameter and productivity, the pulling speed is preferably 300 m/min or more, and in order to prevent thread breakage, it is preferably 4000 m/min or less.

The undrawn fibers thus obtained are temporarily wound before being supplied to the drawing step, or are continuously supplied to the drawing step after being drawn. The stretching is carried out by running the heated first roll or a heating device (for example, in a heating bath or a hot plate) provided between the first roll and the second roll. The stretching conditions are determined according to the mechanical properties of the obtained unstretched fibers, the stretching temperature is determined by the temperature of the heated first roll or the heating device provided between the first roll and the second roll, and the stretching ratio is determined by the first roll. The peripheral speed ratio of the roll and the second roll is determined.

Furthermore, after passing through the second roll, the drawn fiber may be heated by the heated third roll or by a heating device provided between the second roll and the third roll, and heat setting may be performed. Crystallization proceeds by heat setting, and it becomes a conductive fiber with excellent shape stability.

The drawn fiber obtained by the above-mentioned production method can be made into a three-dimensional coil shape in a state after drawing by performing the aforementioned composite fiberizing, adjusting the cooling conditions, and the like. In addition, mechanical crimping may be imparted to the obtained stretched fibers using a crimping pliers, a gear, or the like.

The obtained crimped fibers are subjected to metal plating treatment in order to form a metal layer on the fiber surface. The metal for metal plating is not particularly limited as long as it can satisfy the electrical conductivity of the present invention. From the viewpoints of electrical conductivity and cost, copper and/or silver are preferred. In addition, the metal plating treatment system may be any method as long as a metal layer can be formed on the crimped fiber, and examples thereof include electroless metal plating, electrolytic metal plating, molten metal plating, vacuum vapor deposition, and chemical vapor deposition. Plating method, physical vapor deposition method, etc. Moreover, in order to make formation of a metal layer relatively easy before performing a metal plating process, a surface modification process etc. may be performed.

The conductive fiber obtained by the above-mentioned production method and having a metal layer formed on the surface of the crimped fiber is assembled into textiles such as woven fabrics and knitted fabrics. When assembling to a fabric or a knitted fabric, for example, a method of using the conductive fiber of the present invention in a part or all of the fibers used in the manufacturing step, or sewing the fabric of the present invention to a fabric or a knitted fabric composed of other fibers can be used. Methods of conducting fibers, etc. The quilt of the invention is sewn using the textile product (fabric, knit) thus obtained. Moreover, for example, the method of sewing the electrically conductive fiber of this invention directly to a quilt, etc. are mentioned. In addition, when the conductive fiber of the present invention is incorporated into an electrical and electronic device, a method similar to that of a general electrical wiring such as a copper wire can be adopted. [Example]

Next, the present invention will be described in detail based on the embodiments. However, the present invention is not limited to these embodiments. In addition, the measurement of each physical property was performed according to the above-mentioned method unless otherwise stated.

(1) Total fineness The measurement was carried out as described above using the electric spinning machine "YC-1" manufactured by INTEC Co., Ltd.

(2) Average single fiber diameter For the single fiber taken out from the multifilament, a scanning electron microscope "S-5500" manufactured by Hitachi High-Tech Co., Ltd. was used to capture an image at a magnification at which the entire cross-section of the single fiber could be observed. Then, the image analysis software was measured as described above using "WinROOF2015" manufactured by Mitani Corporation.

(3) Average number of curls The single fiber taken out from the multifilament was measured as described above using a digital microscope "VHX-2000" equipped with a large-range zoom lens "VH-Z100R" manufactured by KEYENCE Co., Ltd.

(4) Breaking strength, breaking elongation, 10% modulus The measurement was performed as described above using a tensile testing machine "Tensioner UCT100" manufactured by ORIENTEC Co., Ltd.

(5) Volume resistivity, volume resistivity at 10% elongation The measurement was performed as described above using an insulation resistance meter "SM-8220" manufactured by Toa DKK Co., Ltd.

(6) The stability of electrical properties against deformation is a polyester stretchable knitted fabric (puff loop, basis weight 170 g/m ² ) that has a breaking elongation of at least 15% in either direction, and does not contain a conductive layer, The conductive fibers obtained in Examples and Comparative Examples were sewed at intervals of 3 cm in the direction of high elongation (straight stitches, stitch length 0.5 cm). Next, stretch the stretch fabric by 10% in the direction of high elongation, and then return to the unloaded state, then tie the ends in such a way that the stitches do not loosen, and fix the 2 stitches. The ends of the two stitches are connected to the terminals of Nidec Corporation's axial-flow DC fan "D02X (rated voltage 5V)", and the other end of the stitches is connected to a DC power supply with an output voltage of 5V. Then, while circulating the current to rotate the fan, repeat the 10% expansion and contraction (back and forth) 10 times at a speed of 3 seconds/time, and rated "A" if "the fan rotates sufficiently and the number of rotations of the fan during expansion and contraction does not change"(Good)", rated "B (slightly poor)" for "the number of revolutions of the fan during expansion and contraction", and "C (poor)" for "the fan rotates significantly slower, or the fan stops rotating")" to evaluate the electrical stability against deformation.

[Example 1] High-viscosity polyethylene terephthalate (PET) with inherent viscosity of polymer A of 0.9dL/g and low-viscosity PET with inherent viscosity of polymer B of 0.6dL/g were vacuum dried at 150°C for 12 hours After that, melt spinning was performed at a spinning temperature of 290°C. During melt spinning, high-viscosity PET and low-viscosity PET are melt-extruded by separate twin-shaft extruders, metered by a gear pump, and guided to a spinneret. Then, in the spinneret, the side-to-side type with a volume ratio of high-viscosity PET: low-viscosity PET=50:50 is shaped and merged. The discharge amount was 0.82 g/min.

After the yarn discharged from the spinning nozzle passed through a 50 mm heat preservation area, it was air-cooled through 1.0 m under the conditions of a temperature of 25° C. and a wind speed of 30 m/min using a unidirectional flow cooling device. Then, an oiling agent was applied 2.0 m below the surface of the spinning nozzle, 36 filaments were bundled, passed through the first godet roll and the second godet roll at 1000 m/min, and were wound up by a winder to obtain unstretched fibers. .

The above-mentioned undrawn fibers were drawn by a feed roll provided with a nip roll, and after the undrawn fibers were provided with tension between the first roll and the first roll, the undrawn fibers were heated to 90°C on the first roll and the second roll 6 times. Apply heat extension. Then, it wound around 6 times on the 3rd roll heated to 140 degreeC, and performed heat setting. The total stretching ratio was 3.50 times, and after passing through the third roll, the stretched fiber was obtained by winding through a winder through a non-heated roll having a peripheral speed of 400 m/min.

The surface of the elongated fiber was cleaned and degreased, and after an etching treatment was performed, a palladium catalyst was carried on the surface of the fiber, and then a copper plating treatment was performed in a copper sulfate aqueous solution.

The obtained conductive fibers were evaluated for total fineness, average single fiber diameter, average number of crimps, breaking strength, elongation at break, volume resistivity, volume resistivity at 10% elongation, and stability of electrical properties against deformation. The evaluation results are shown in Table 1.

[Example 2, 3] Conductive fibers were obtained in the same manner as in Example 1, except that the output per hole in the spinning step was changed to 1.40 g/min in Example 2 and 0.56 g/min in Example 3. The evaluation results of the obtained conductive fibers are shown in Table 1.

[Example 4] Conductive fibers were obtained in the same manner as in Example 1, except that the volume ratio of the spinning step was set to high-viscosity PET:low-viscosity PET=20:80. The evaluation results of the obtained conductive fibers are shown in Table 1.

[Example 5] Conductive fibers were obtained in the same manner as in Example 1, except that the polymer A was polybutylene terephthalate (PBT) "TORAYCON 1200M" manufactured by Toray Co., Ltd. The evaluation results of the obtained conductive fibers are shown in Table 2.

[Example 6] Conductive fibers were obtained in the same manner as in Example 1, except that in the spinning step, polymer A was placed in the sheath and polymer B was placed in the core to form an eccentric core-sheath composite fiber with an eccentricity of 0.30. The evaluation results of the obtained conductive fibers are shown in Table 2.

[Comparative Example 1] The polymer A used melt-kneaded polytrimethylene terephthalate (PPT-CB) made of furnace black (form L, average particle size 23 μm) manufactured by Degussa, and the polymer B used isophthalic acid (IPA). 7 mol%, bisphenol A-ethylene oxide adduct (BPA-EO) 4 mol% copolymerized PET (copolymerized PET), using extended fibers composed of polymer A and polymer B, Conductive fibers were obtained in the same manner as in Example 6 except that the metal plating treatment was not performed. The evaluation results of the obtained conductive fibers are shown in Table 2.

[Example 7] Except in the spinning step, only the polymer A was discharged using a hollow type spinning nozzle (slit width 0.08 mm, slit diameter 0.8 mm, 3 slits), and then a unidirectional flow cooling device was used at a wind speed of 50 m/min. The conductive fibers were obtained in the same manner as in Example 1, except that unextended fibers with poor molecular orientation in the fiber cross-sectional direction were obtained by air-cooling under the same conditions. The evaluation results of the obtained conductive fibers are shown in Table 3.

[Comparative Example 2] The stretched fiber used a polyurethane elastic fiber "LYCRA T-127" manufactured by TORAY OPELONTEX Co., Ltd., and was subjected to copper plating treatment in the same manner as in Example 1 to obtain a conductive fiber. The evaluation results of the obtained conductive fibers are shown in Table 3.

[Table 1] Table 1 project Example 1 Example 2 Example 3 Example 4 Compound Morphology side to side side to side side to side side to side polymer A High viscosity PET High viscosity PET High viscosity PET High viscosity PET ratio[%] 50 50 50 20 polymer B Low viscosity PET Low viscosity PET Low viscosity PET Low viscosity PET ratio[%] 50 50 50 80 Total fineness [dtex] 101 173 67 101 Average single fiber diameter [μm] 14.8 19.4 12.3 14.8 Average number of curls [pieces/cm] 11 6 13 3 crimped shape three-dimensional coil three-dimensional coil three-dimensional coil three-dimensional coil Breaking strength [cN/dtex] 2.7 2.1 3.1 2.5 Elongation at break[%] 55 63 42 45 10% Modulus [cN/dtex] 0.08 0.21 0.05 0.93 metal layer copper plated copper plated copper plated copper plated Volume resistivity [Ω•cm] 9.3× ^10-5 1.3× ^10-4 4.9× ^10-5 8.6× ^10-5 Volume resistivity at 10% elongation [Ω•cm] 7.4× ^10-5 1.4× ^10-4 4.1× ^10-5 8.5× ^10-4 Electrical stability against deformation A A A A

[Table 2] Table 2 project Example 5 Example 6 Comparative Example 1 Compound Morphology side to side Eccentric core sheath Eccentric core sheath polymer A PBT High viscosity PET PPT-CB ratio[%] 50 50 50 polymer B Low viscosity PET Low viscosity PET Co-lapped PET ratio[%] 50 50 50 Total fineness [dtex] 107 102 105 Average single fiber diameter [μm] 15.1 14.8 15.0 Average number of curls [pieces/cm] 11 7 10 crimped shape three-dimensional coil three-dimensional coil three-dimensional coil Breaking strength [cN/dtex] 2.6 2.9 2.1 Elongation at break[%] 52 48 68 10% Modulus [cN/dtex] 0.06 0.18 0.08 metal layer copper plated copper plated - Volume resistivity [Ω•cm] 8.1× ^10-5 9.3× ^10-5 5.8×10 ¹ Volume resistivity at 10% elongation [Ω•cm] 6.9× ^10-5 8.1× ^10-5 3.2×10 ¹ Electrical stability against deformation A A C

[table 3] table 3 project Example 7 Comparative Example 2 Section shape hollow round polymer High viscosity PET Polyurethane Total fineness [dtex] 110 106 Average single fiber diameter [μm] 17.2 34.1 Average number of curls [pieces/inch] 5 0 crimped shape three-dimensional coil - Breaking strength [cN/dtex] 2.3 2.1 Elongation at break[%] 48 581 10% Modulus (cN/dtex) 0.32 0.03 metal layer copper plated copper plated Volume resistivity [Ω•cm] 1.2× ^10-4 1.8× ^10-4 Volume resistivity at 10% elongation [Ω•cm] 1.0× ^10-4 Unable to measure (upper limit of measurement) Electrical stability against deformation A C

In addition to the total fineness being within a specific range, Examples 1 to 7 have a large average crimp number and a low 10% modulus, so they are excellent in flexibility, and because they are provided with a metal layer, their volume resistivity is low, and the The electrical characteristics of deformation are excellent in stability.

On the other hand, it was found that the comparative example 1 had high volume resistivity, so electricity was not easy to flow, and the fan was driven; in addition, when the comparative example 2 was stretched by 10%, the metal layer on the surface was destroyed, resulting in a significant decrease in electrical conductivity, and the fan was rotated. stop, so the electrical characteristics of the deformation stability is poor.

The specific aspects of the present invention have been described in detail, but various modifications and changes can be made without departing from the spirit and scope of the present invention, which can be easily conceived by those skilled in the art. In addition, this application is based on the Japanese Patent Application (Japanese Patent Application No. 2020-127087) for which it applied on July 28, 2020, and the whole content is incorporated by reference in this application.

Claims (7)

A conductive fiber, the average number of crimps is 2 pieces/cm or more, and a metal layer is arranged on the surface of the fiber, the volume resistivity is 2×10 ^-6 ~1×10 ^-2 Ω·cm, and the total fineness is 10~1000dtex . The conductive fiber of claim 1, wherein the average single fiber diameter is 5-20 μm. The conductive fibers of claim 1 or 2 are composed of long fibers. The conductive fiber according to any one of claims 1 to 3, wherein the volume resistivity when stretched by 10% in the direction of the fiber axis is 2×10 ^-6 to 1×10 ^-2 Ω·cm. The conductive fiber according to any one of claims 1 to 4, wherein the crimped shape is a three-dimensional coil shape. A quilt, at least a part of which is composed of the conductive fibers of any one of claims 1 to 5. An electrical and electronic machine, at least a part of which is covered by claims 1 to 5 It is composed of any one of the conductive fibers.