JPWO2019069660A1 - Piezoelectric yarn - Google Patents

Abstract

The problem to be solved by the invention is to provide a piezoelectric yarn that has a longer effect than conventional materials having antibacterial properties and is higher in safety than drugs and the like. The piezoelectric yarn (51) of the present invention is obtained by turning a plurality of lower twisted yarns (52) twisted by twisting a piezoelectric yarn made of a functional polymer that generates an electric charge by external energy, and further twisting the upper twisted yarn. Comprising.

Description

  One embodiment of the present invention relates to a piezoelectric fiber having antibacterial properties.

  Conventionally, many proposals have been made for fiber materials having antibacterial properties (see Patent Documents 1 to 7).

Japanese Patent No. 3281640 JP-A-7-310284 Japanese Patent No. 316,992 Japanese Patent No. 1805853 JP-A-8-226078 JP-A-9-194304 JP 2004-300650 A

  However, none of the materials having antibacterial properties exhibited long-lasting effects.

  In addition, an antibacterial material may cause an allergic reaction due to a drug or the like.

  Therefore, an object of one embodiment of the present invention is to provide a piezoelectric fiber that lasts longer than conventional antibacterial materials and is safer than drugs and the like.

  The piezoelectric fiber according to one embodiment of the present invention includes an upper twisted yarn further twisted from a plurality of lower twisted yarns that are twisted by twisting a piezoelectric yarn made of a functional polymer that generates electric charges by external energy. It is characterized by the following.

  It has been known that the growth of bacteria and fungi can be suppressed by an electric field (for example, see Tetsuaki Doto, Hironori Korei, Hideaki Matsuoka, Junichi Koizumi, Kodansha: Microbial Control-Science and Engineering) Also, see, for example, Koichi Takagi, Application of High Voltage / Plasma Technology to Agriculture / Food, J. HTSJ, Vol.51, No.216). Further, depending on the potential generating the electric field, a current may flow through a current path formed by moisture or the like or a circuit formed by a local micro discharge phenomenon or the like. It is conceivable that this current weakens the bacteria and suppresses the growth of the bacteria. Since the piezoelectric fiber according to one embodiment of the present invention includes a plurality of charge generating fibers that generate electric charges by external energy, a predetermined electric potential (ground electric potential) between the fibers or the human body or the like is set. An electric field is generated when it comes close to an object having Alternatively, when the piezoelectric fiber according to an embodiment of the present invention is close to an object having a predetermined potential (including a ground potential) such as a human body between the fibers or a human body via moisture such as sweat. Current.

  Therefore, the piezoelectric fiber according to one embodiment of the present invention exhibits an antibacterial effect for the following reasons. The direct action of an electric field or electric current generated when applied to an object (clothing, footwear, or a medical article such as a mask) used in close proximity to an object having a predetermined electric potential such as a human body, thereby causing a cell membrane of a bacterium or a bacterium to be generated. The electron transport system for maintaining the life of the bacterium is hindered, and the bacterium is killed or the bacterium itself is weakened. In addition, oxygen contained in water may be changed to reactive oxygen species by an electric field or electric current, or oxygen radicals may be generated in bacterial cells by a stress environment due to the presence of the electric field or electric current. Bacteria are killed or weakened by the action of reactive oxygen species including radicals. In some cases, the above reasons are combined to produce an antibacterial effect. The term “antibacterial” used in the present invention is a concept that includes both an effect of suppressing the occurrence of bacteria and an effect of killing bacteria.

  Note that the charge generation fiber that generates a charge by external energy may be, for example, a substance having a photoelectric effect, a substance having a pyroelectric effect, or a fiber using a piezoelectric body or the like. In addition, a structure in which an insulator is wound around the conductor using a conductor as a core yarn, and a voltage is applied to the conductor to generate charges, also constitutes a charge generation fiber.

  When a piezoelectric body is used, an electric field is generated by piezoelectricity, so that a power source is not required and there is no risk of electric shock. Further, the life of the piezoelectric body lasts longer than the antibacterial effect of a drug or the like. Also, the risk of allergic reactions is lower than that of drugs.

  Furthermore, the piezoelectric fiber according to one embodiment of the present invention can have various variations in the piezoelectric fiber itself by adjusting the number of twists of the lower twisted yarn and the number of twists of the upper twisted yarn.

  The piezoelectric fiber according to an embodiment of the present invention includes a covering yarn twisted by twisting a piezoelectric yarn made of a functional polymer that generates an electric charge by external energy, and the covering yarn is arranged in an axial direction. It is wound so that it turns.

  The piezoelectric fiber according to one embodiment of the present invention can have various variations in the piezoelectric fiber itself by adjusting the number of twists of the lower twisted yarn and the number of windings of the covering yarn.

  According to the present invention, it is possible to realize a piezoelectric fiber that has a longer effect than conventional materials having antibacterial properties and is higher in safety than drugs and the like.

FIG. 1A is a diagram showing the configuration of the upper twisted yarn in the piezoelectric fiber according to the first embodiment, and FIG. 1B is a cross-sectional view of FIG. 1A. FIG. 2 (A) is a partially enlarged view of FIG. 1 (A) for explaining the configuration of the lower twisted yarn in the piezoelectric fiber according to the first embodiment, and FIG. 2 (B) is FIG. FIG. FIGS. 3A and 3B are diagrams showing the relationship among the uniaxial stretching direction of polylactic acid, the electric field direction, and the deformation of the piezoelectric fiber. FIG. 4 illustrates the shear stress (shear stress) generated in each piezoelectric fiber when tension is applied to the piezoelectric fiber. FIG. 5A is a diagram showing the configuration of the upper twisted yarn in the piezoelectric fiber according to the second embodiment, and FIG. 5B is for explaining the configuration of the lower twisted yarn in the piezoelectric fiber according to the second embodiment. FIG. 5 (A) is a partially enlarged view of FIG. FIG. 6A is a diagram illustrating a configuration of a covering yarn in the piezoelectric fiber according to the third embodiment, and FIG. 6B is a diagram illustrating a configuration of a twisted yarn in the piezoelectric fiber according to the third embodiment. FIG. 7 is a partially enlarged view of FIG. FIGS. 7A to 7C are schematic cross-sectional views illustrating a modified example of the lower twisted yarn according to the first embodiment.

  FIG. 1A is a diagram showing the configuration of the upper twisted yarn in the piezoelectric fiber according to the first embodiment, and FIG. 1B is a cross-sectional view of FIG. 1A cut along II. 1A and 1B show a piezoelectric fiber in which seven lower twisted yarns are twisted as an example, the number of the lower twisted yarns is not limited to this, and in practice It is set appropriately in consideration of the above.

  As shown in FIGS. 1A and 1B, the piezoelectric fiber 11 includes an upper twisted yarn (multifilament yarn) formed by twisting a plurality of lower twisted yarns 21. The piezoelectric fiber 11 is a right-handed yarn (hereinafter, referred to as an S yarn) that is formed by twisting the lower twisted yarn 21 rightward.

  In the piezoelectric fiber 11, the longitudinal direction 201 of the lower twist yarn 21 is inclined leftward with respect to the axial direction 101 of the piezoelectric fiber 11. The angle of inclination of the lower twisted yarn 21 with respect to the axial direction 101 of the piezoelectric fiber 11 depends on the number of twists of the piezoelectric fiber 11.

  In the piezoelectric fiber 11, as the number of twists increases, the angle of the longitudinal direction 201 of the lower twisted yarn 21 at the outer peripheral portion of the piezoelectric fiber 11 with respect to the axial direction 101 of the piezoelectric fiber 11 increases. Therefore, by adjusting the number of twists of the piezoelectric fiber 11, the inclination angle of the lower twisted yarn 21 in the outer peripheral portion of the piezoelectric fiber 11 with respect to the axial direction 101, that is, θ1 shown in FIG. 1A can be adjusted. For example, θ1 can be set to 10 to 25 degrees. By setting θ1 to 10 to 25 degrees, the piezoelectric fibers 11 can maintain an appropriate elasticity while stably maintaining the shape of the upper twisted yarn, which is a bundle of the lower twisted yarns 21.

  FIG. 2A is an enlarged view of a region surrounded by a dashed circle A1 in FIG. 1A for explaining the configuration of the lower twisted yarn in the piezoelectric fiber according to the first embodiment, and FIG. 2) is a cross-sectional view of FIG. 2 (A) obtained by cutting one lower twisted yarn along II-II.

  As shown in FIGS. 2A and 2B, the lower twist yarn 21 includes a multifilament yarn formed by twisting a plurality of piezoelectric yarns 31. The lower twist yarn 21 is a right turn yarn (hereinafter, referred to as an S yarn) which is formed by turning the piezoelectric yarn 31 right and twisting. That is, the lower twisted yarn 21 is twisted in the same direction as the piezoelectric fiber 11 that is the upper twisted yarn.

  The piezoelectric yarn 31 is an example of a charge generation fiber (charge generation yarn) that generates charges by external energy.

  The piezoelectric thread 31 is made of a functional polymer, for example, a piezoelectric polymer. Examples of the piezoelectric polymer include polylactic acid (PLA). Polylactic acid (PLA) is a piezoelectric polymer having no pyroelectricity. Polylactic acid generates piezoelectricity by being uniaxially stretched. Polylactic acid includes PLLA in which an L-form monomer is polymerized and PDLA in which a D-form monomer is polymerized. Note that the piezoelectric yarn 31 may further include a material other than the functional polymer as long as the function does not inhibit the function of the functional polymer.

Polylactic acid is a chiral polymer, and the main chain has a helical structure. Polylactic acid develops piezoelectricity when molecules are oriented by uniaxial stretching. When the crystallinity is further increased by heat treatment, the piezoelectric constant increases. The piezoelectric yarn 31 made of uniaxially stretched polylactic acid has a thickness direction defined as a first axis, a stretching direction 202 defined as a third axis, and a direction orthogonal to both the first and third axes defined as a second axis. having a tensor components of _{d 14} and _{d 25} as the piezoelectric strain constant. Therefore, polylactic acid generates electric charges most efficiently when distortion occurs in a direction of 45 degrees with respect to the uniaxially stretched direction.

  FIGS. 3A and 3B are diagrams showing the relationship between the uniaxial stretching direction 202 of polylactic acid, the direction of the electric field, and the deformation of the piezoelectric yarn 31. As shown in FIG. 3A, when the piezoelectric yarn 31 contracts in the direction of the first diagonal line 910A and extends in the direction of the second diagonal line 910B orthogonal to the first diagonal line 910A, the piezoelectric yarn 31 moves in the direction from the back side of the paper to the front side. Generates an electric field. That is, the piezoelectric yarn 31 generates a negative charge on the front side of the drawing. As shown in FIG. 3B, when the piezoelectric yarn 31 extends in the direction of the first diagonal line 910A and contracts in the direction of the second diagonal line 910B, it generates a charge, but the polarity is reversed, and An electric field is generated in the direction from the back to the back side. That is, the piezoelectric yarn 31 generates a positive charge on the front side of the drawing.

  Since polylactic acid generates piezoelectricity by molecular orientation treatment by stretching, it is not necessary to perform a poling treatment unlike other piezoelectric polymers such as PVDF or piezoelectric ceramics. The uniaxially stretched polylactic acid has a piezoelectric constant of about 5 to 30 pC / N, and has a very high piezoelectric constant among polymers. Furthermore, the piezoelectric constant of polylactic acid does not fluctuate with time and is extremely stable.

  The piezoelectric yarn 31 is a fiber having a circular cross section. The piezoelectric yarn 31 is formed, for example, by a method of extruding a piezoelectric polymer into fibers and a method of melt-spinning the piezoelectric polymer into fibers (for example, a spinning / drawing method in which a spinning step and a drawing step are performed separately). Including the direct drawing method in which the spinning and drawing steps are connected, the POY-DTY method in which the false twisting step can be performed at the same time, and the ultra-high-speed prevention method in which the speed is increased.) Spinning (for example, a phase separation method or a dry-wet spinning method in which a raw material polymer is dissolved in a solvent and extruded from a nozzle to form fibers, a gel spinning method in which fibers are uniformly formed into a gel while containing a solvent, Or a liquid crystal spinning method of forming a fiber using a liquid crystal solution or a melt, or the like, or a method of forming a piezoelectric polymer into a fiber by electrostatic spinning. Note that the cross-sectional shape of the piezoelectric yarn 31 is not limited to a circle.

  Similarly to the piezoelectric fiber 11, in the lower twisted yarn 21, the stretching direction 202 of the piezoelectric yarn 31 is inclined leftward with respect to the longitudinal direction 102 of the lower twisted yarn 21. The angle of inclination of the piezoelectric yarn 31 with respect to the longitudinal direction 102 of the lower twisted yarn 21 depends on the number of twists of the lower twisted yarn 21. Accordingly, by adjusting the number of twists of the lower twisted yarn 21, the angle of inclination of the piezoelectric yarn 31 at the outer peripheral portion of the piezoelectric yarn 31 with respect to the longitudinal direction 102, that is, θ2 shown in FIG. 2A can be adjusted. For example, θ2 can be set to 20 to 35 degrees. By setting θ2 to 20 to 35 degrees, the rigidity of the lower twisted yarn 21 can be maintained.

  FIG. 4 illustrates the shear stress (shear stress) generated in each piezoelectric fiber when tension is applied to the piezoelectric fiber. As shown in FIG. 4, when tension is applied to the piezoelectric fiber 11, a force in the axial direction 101 of the piezoelectric fiber 11 is applied to the lower twisted yarn 21 constituting the piezoelectric fiber 11. At this time, a force in the axial direction 101 of the piezoelectric fiber 11 is applied to the piezoelectric yarn 31 constituting the lower twisted yarn 21.

  When tension is applied to the piezoelectric yarn 31 of the lower twist yarn 21 that is the S yarn, the surface of the piezoelectric yarn 31 is in a state as shown in FIG. Therefore, a negative charge is generated on the surface of the piezoelectric fiber 11, and a positive charge is generated on the inside.

  The piezoelectric fiber 11 generates an electric field by a potential difference generated by the electric charge. This electric field leaks into the nearby space to form a coupling electric field with other parts. In addition, when the electric potential generated in the piezoelectric fiber 11 is close to an object having a predetermined electric potential close thereto, for example, a human body or the like having a predetermined electric potential (including a ground electric potential), an electric field is generated between the piezoelectric fiber 11 and the object. Cause.

  It has been known that the growth of bacteria and fungi can be suppressed by an electric field (for example, see Tetsuaki Doto, Hironori Korai, Hideaki Matsuoka, Junichi Koizumi, Kodansha: Microbial Control-Science and Engineering). Also, see, for example, Koichi Takagi, Application of High Voltage and Plasma Technology to Agriculture and Food Fields, J.HTSJ, Vol.51, No.216). Further, depending on the potential generating the electric field, a current may flow through a current path formed by moisture or the like or a circuit formed by a local micro discharge phenomenon or the like. It is conceivable that this current weakens the bacteria and suppresses the growth of the bacteria. In addition, the bacteria referred to in the present embodiment include bacteria, fungi, and microorganisms such as mites and fleas.

  Accordingly, the piezoelectric fiber 11 directly exerts an antibacterial effect by an electric field formed in the vicinity of the piezoelectric fiber 11 or by an electric field generated when approaching an object having a predetermined potential such as a human body. Alternatively, the piezoelectric fiber 11 allows a current to flow when approaching an object having a predetermined potential, such as another adjacent fiber or a human body, via moisture such as sweat. Even with this current, the antibacterial effect may be directly exerted. Alternatively, active oxygen species in which oxygen contained in water is changed by the action of electric current or voltage, radical species generated by interaction or catalysis with an additive contained in fiber, or other antibacterial chemical species (amine Derivatives, etc.) may exert an antimicrobial effect indirectly. Alternatively, oxygen radicals may be generated in the cells of the bacterium due to a stress environment caused by the presence of an electric field or electric current, whereby the piezoelectric fibers 11 may indirectly exert an antibacterial effect. In addition, the left-handed yarn twisted by turning the piezoelectric yarn 31 counterclockwise can also exert the antibacterial effect directly or indirectly similarly to the piezoelectric fiber 11. As the radical, generation of a superoxide anion radical (active oxygen) or a hydroxyl radical is considered. The term “antibacterial” in the present embodiment is a concept that includes both an effect of suppressing the occurrence of bacteria and an effect of killing bacteria.

  By adjusting the number of twists of the lower twist yarn 21 and the number of twists of the piezoelectric fiber 11 which is the upper twist yarn, the angles θ1 and θ2 can be adjusted. In the first embodiment, the lower twisted yarn 21 is twisted such that the piezoelectric yarn 31 is at 45 degrees or less with respect to the longitudinal direction 102, and the piezoelectric fiber 11 that is the upper twisted yarn is oriented in the same direction as the lower twisted yarn 21. It is preferably twisted. Thereby, θ3, which is the sum of θ1 and θ2, can be adjusted.

  Here, when the angle of θ1 is smaller than θ2, that is, when the number of twists of the piezoelectric fiber 11 is smaller than the number of twists of the lower twisted yarn 21, the twist of the lower twisted yarn 21 appearing on the surface is small, so that soft touch can be obtained. . Conversely, when the angle of θ2 is smaller than θ1, that is, when the number of twists of the piezoelectric fiber 11 is larger than the number of twists of the lower twisted yarn 21, the lower twisted yarn 21 appearing on the surface is more twisted, so that a strong fiber that is difficult to unravel is obtained. be able to. If the piezoelectric fibers 11 are difficult to unwind, the piezoelectric fibers 11 can obtain stable antibacterial properties.

  θ3 is the angle of the stretching direction 202 of the piezoelectric yarn 31 at the outer peripheral portion of the lower twisted yarn 21 with respect to the axial direction 101 of the piezoelectric fiber 11 as shown in FIG. For example, θ3 can be set to 35 to 55 degrees. By setting the angle θ3 of the piezoelectric yarn 31 with respect to the axial direction 101 of the piezoelectric fiber 11 to 35 to 55 degrees, when the piezoelectric fiber 11 expands and contracts in the axial direction 101, the angle θ3 becomes 35 to 55 with respect to the stretching direction 202 of the piezoelectric yarn 31. Since it is expanded and contracted in the direction of the angle, power can be efficiently generated.

  When only the piezoelectric yarn 31 is twisted so that the angle of the piezoelectric fiber 11 with respect to the axial direction 101 is 35 to 55 degrees, the number of twists of the piezoelectric yarn 31 becomes considerably large. As a result, a load is applied to the piezoelectric yarn 31 and the piezoelectric yarn 31 is easily cut, and thus the durability of the piezoelectric fiber 11 may be weakened.

  In the first embodiment, the lower twisted yarn 21 and the piezoelectric fiber 11 are both S yarns that are turned clockwise and twisted. However, the lower twisted yarn 21 and the piezoelectric fiber 11 are both turned leftward and twisted left. (Hereinafter, referred to as a Z yarn). Thereby, the angle of the piezoelectric yarn 31 with respect to the axial direction 101 of the piezoelectric fiber 11 can be set to 35 to 55 degrees, and the same effect can be obtained.

  The piezoelectric fiber 11 as described above can be applied to various kinds of clothing or products such as medical members. For example, the piezoelectric fibers 11 include underwear (especially socks), insoles for towels, shoes and boots, sportswear in general, hats, bedding (including futons, mattresses, sheets, pillows, pillowcases, etc.), toothbrushes, floss, Various filters (filters for water purifiers, air conditioners or air purifiers), stuffed animals, pet-related products (mats for pets, pet clothes, inner clothes for pets), various mat products (foot, hand, toilet seat, etc.) , Curtains, kitchen utensils (sponge or cloth, etc.), seats (seats for cars, trains, airplanes, etc.), cushioning materials for motorcycle helmets and their exterior materials, sofas, bandages, gauze, masks, sutures, doctors and patients Applicable to clothes, supporters, sanitary goods, sports goods (wear and glove innerwear, karate used in martial arts, etc.), or packaging materials. Can.

  Of clothing, in particular, socks (or supporters) always expand and contract along joints due to movements such as walking, so that the piezoelectric fibers 11 generate electric charges at high frequency. In addition, socks absorb moisture such as sweat and serve as a breeding ground for bacterial growth. However, since the piezoelectric fibers 11 can suppress bacterial growth, they have a remarkable effect as a fungus control application for deodorization. Occurs.

  Further, the piezoelectric fiber 11 can also be used as a method for controlling the bacterium on the body surface of an animal excluding a human, and a cloth including a piezoelectric body is arranged so as to face at least a part of the skin of the animal, The electric charge generated when an external force is applied to the piezoelectric body may suppress the growth of bacteria on the body surface of the animal facing the cloth. Thereby, it is possible to suppress the growth of bacteria on the body surface of an animal and to treat a skin disease derived from Trichophyton on the body surface of an animal in a simple manner, which is safer than the use of drugs and the like. it can.

  In addition, the piezoelectric fiber of this embodiment has the following uses other than the antibacterial use.

(1) Biologically acting piezoelectric fiber product Many tissues constituting a living body have piezoelectricity. For example, collagen constituting the human body is a kind of protein, and is contained in a large amount in blood vessels, dermis, ligaments, healthy, bone, cartilage and the like. Collagen is a piezoelectric body, and a tissue in which collagen is oriented may show very large piezoelectricity. Many reports have already been made on the piezoelectricity of bone (see, for example, Eiichi Fukada, Piezoelectricity of biopolymers, Polymer Vol. 16 (1967) No. 9 p795-800, etc.). Accordingly, when an electric field is generated by the piezoelectric fibers provided with the piezoelectric yarns 31 and the electric field alternates or the intensity of the electric field changes, the piezoelectric body of the living body vibrates due to the inverse piezoelectric effect. Due to the alternation of the alternating electric field or the electric field strength generated by the piezoelectric yarn 31, minute vibration is applied to a part of the living body, for example, a capillary or dermis, and it is possible to promote the improvement of the blood flow in that part. This may promote healing of skin diseases and wounds. Therefore, the piezoelectric fiber 11 functions as a biologically active piezoelectric fiber product.

(2) Piezoelectric Fiber Product for Adsorbing Substance As described above, the piezoelectric yarn 31 of the lower twist yarn 21 that is the S yarn generates a negative charge when an external force is applied. The piezoelectric yarn 31 in the case where the lower twist yarn 21 is a Z yarn generates a positive charge when an external force is applied. Therefore, the piezoelectric yarn 31 has a property of adsorbing a substance having a positive charge (eg, particles such as pollen) and adsorbing a substance having a negative charge (eg, a harmful substance such as yellow sand). Therefore, when applied to medical supplies such as a mask, the piezoelectric fibers 11 provided with the piezoelectric threads 31 can adsorb fine particles such as pollen and yellow sand.

  Note that a structure in which an insulator is wound around the conductor using a conductor as the core yarn, and electricity is caused to flow through the conductor to generate charges is also a fiber that generates charges. However, since a piezoelectric body generates an electric field by piezoelectricity, a power source is not required and there is no risk of electric shock. Further, the life of the piezoelectric body lasts longer than the antibacterial effect of a drug or the like. Also, the risk of allergic reactions is lower than that of drugs. In addition, expression of resistant bacteria by drugs, especially antibiotics, etc. has recently become a major problem, but it is unlikely that the sterilization method according to the present invention causes resistant bacteria due to the mechanism.

  In addition, as a fiber that generates a negative charge on the surface, a Z yarn using PDLA is also considered in addition to an S yarn using PLLA. Further, as a fiber that generates a positive charge on the surface, an S yarn using PDLA may be considered in addition to a Z yarn using PLLA.

  FIG. 5A is a diagram showing the configuration of the upper twisted yarn in the piezoelectric fiber according to the second embodiment, and FIG. 5B is for explaining the configuration of the lower twisted yarn in the piezoelectric fiber according to the second embodiment. FIG. 6 is an enlarged view of a region surrounded by a dashed circle A2 in FIG. In the piezoelectric fiber according to the second embodiment, the description of the same configuration as that of the piezoelectric fiber according to the first embodiment is omitted, and only the different configuration will be described.

  As shown in FIG. 5A, the piezoelectric fiber 51 according to the second embodiment includes an upper twisted yarn (multifilament yarn) formed by twisting a plurality of lower twisted yarns 52. The piezoelectric fiber 51 is a Z yarn obtained by twisting the lower twisted yarn 52 by turning left.

  In the piezoelectric fiber 51, the longitudinal direction 501 of the lower twisted yarn 52 is inclined rightward with respect to the axial direction 101 of the piezoelectric fiber 51. By adjusting the number of twists of the lower twisted yarn 52, the angle of inclination of the lower twisted yarn 52 at the outer peripheral portion of the piezoelectric fiber 51 with respect to the axial direction 101, that is, θ4 shown in FIG. For example, θ4 can be set to 10 to 25 degrees. By setting θ4 to 10 to 25 degrees, the piezoelectric fibers 51 can maintain an appropriate elasticity while stably maintaining the shape of the upper twisted yarn, which is a bundle of the lower twisted yarns 52.

  As shown in FIG. 5B, the lower twisted yarn 52 includes a multifilament yarn formed by twisting a plurality of piezoelectric yarns 31. The lower twisted yarn 52 is a Z yarn twisted by turning the piezoelectric yarn 31 counterclockwise. That is, the lower twisted yarn 52 is twisted in a different direction from the piezoelectric fiber 51 that is the upper twisted yarn. By being twisted in a different direction from the upper twisted yarn and the lower twisted yarn 52, the piezoelectric fiber 51 has a stable twist as a whole and is strong, and thus has excellent durability. The same effect can be obtained even if the lower twisted yarn 52 is a Z yarn twisted by turning the piezoelectric yarn 31 counterclockwise and the piezoelectric fiber 51 is an S yarn twisted by turning the lower twisted yarn 52 clockwise. Can be

  By adjusting the number of twists of the lower twisted yarn 52, the inclination angle of the piezoelectric yarn 31 at the outer peripheral portion of the piezoelectric yarn 31 with respect to the longitudinal direction 501, and θ5 shown in FIG. 5B can be adjusted. For example, θ5 can be set to 55 to 70 degrees. By setting θ5 to 55 to 70 degrees, rigidity can be imparted to the lower twisted yarn 52.

  In the second embodiment, the piezoelectric yarn 31 is preferably twisted so as to be at least 45 degrees with respect to the longitudinal direction 501 of the lower twisted yarn 52. Since the piezoelectric fiber 51, which is the upper twisted yarn, is twisted in a direction different from that of the lower twisted yarn 52, the angle θ6 of the piezoelectric yarn 31 with respect to the axial direction 101 of the piezoelectric fiber 51 is obtained by subtracting θ4 from θ5. This makes it possible to adjust θ6, which is the difference between θ4 and θ5. For example, θ6 can be set to 35 to 55 degrees. By setting the angle θ6 of the piezoelectric yarn 31 with respect to the axial direction 101 of the piezoelectric fiber 51 to 35 to 55 degrees, when the piezoelectric fiber 51 expands and contracts in the axial direction 101, the angle θ6 becomes 35 to 55 with respect to the stretching direction 202 of the piezoelectric yarn 31. Since it is expanded and contracted in the direction of the angle, power can be efficiently generated.

  FIG. 6A is a diagram illustrating a configuration of a covering yarn in the piezoelectric fiber according to the third embodiment, and FIG. 6B is a diagram illustrating a configuration of a twisted yarn in the piezoelectric fiber according to the third embodiment. It is the figure which expanded the area | region enclosed with the broken-line circle A3 of FIG. 6 (A). In the piezoelectric fiber according to the third embodiment, the description of the same configuration as the piezoelectric fiber according to the first embodiment will be omitted, and only different configurations will be described.

  As shown in FIG. 6A, a piezoelectric fiber 61 according to the third embodiment includes a shaft 62 and a covering thread 63. The covering thread 63 is wound around the shaft 62 so as to rotate with respect to an axis parallel to the axis direction 101 of the shaft 62. For example, the covering thread 63 is wound around the axis 62 while turning left. Thus, the shaft 62 has a property that the covering thread 63 does not have, so that a new property can be given to the piezoelectric fiber 61. Note that the covering yarn 63 may be wound around the shaft 62 while turning rightward.

  For example, if the material of the shaft 62 has elasticity, the elasticity can be imparted to the piezoelectric fiber even if the covering yarn 63 does not have elasticity. Note that the shaft 62 is not always necessary, and may be configured with only the covering thread 63.

  The covering yarn 63 is wound at an angle θ7 with respect to an axis parallel to the axial direction 101 of the shaft 62. For example, θ7 can be set to 20 to 35 degrees. As shown in FIG. 6B, the covering yarn 63 is a Z yarn obtained by twisting a plurality of piezoelectric yarns 31 by turning left. The piezoelectric yarn 31 is twisted at an angle θ8 with respect to the longitudinal direction 601 of the covering yarn 63.

  By adjusting the number of twists of the covering yarn 63, the inclination angle of the piezoelectric yarn 31 at the outer peripheral portion of the piezoelectric yarn 31 with respect to the longitudinal direction 601 and θ8 shown in FIG. 6B can be adjusted. For example, θ8 can be set to 10 to 25 degrees. By setting θ8 to 10 to 25 degrees, the rigidity of the covering yarn 63 can be maintained.

  In the third embodiment, the piezoelectric yarn 31 is preferably twisted so as to be at most 45 degrees to the longitudinal direction 601 of the covering yarn 63. In this case, since the piezoelectric fiber 61 is wound in the same direction as the covering yarn 63, the angle θ9 of the piezoelectric yarn 31 with respect to the axial direction 101 of the piezoelectric fiber 61 is obtained by adding θ8 to θ7. This makes it possible to adjust θ9, which is the sum of θ7 and θ8. For example, θ9 can be set to 35 to 55 degrees. By setting the angle θ9 of the piezoelectric yarn 31 with respect to the axial direction 101 of the piezoelectric fiber 61 to 35 to 55 degrees, when the piezoelectric fiber 61 expands and contracts in the axial direction 101, the angle θ9 becomes 35 to 55 with respect to the stretching direction 202 of the piezoelectric yarn 31. Since it is expanded and contracted in the direction of the angle, power can be efficiently generated.

  Further, in the third embodiment, the piezoelectric yarn 31 may be twisted so as to be at least 45 degrees with respect to the longitudinal direction 601 of the covering yarn 63. In this case, the piezoelectric fibers 61 need to be wound in a different direction from the covering yarn 63. Although not shown, similarly to the second embodiment, the angle θ9 of the piezoelectric thread 31 with respect to the axial direction 101 of the piezoelectric fiber 61 is obtained by subtracting θ7 from θ8. This makes it possible to adjust θ9, which is the difference between θ7 and θ8. Also in this case, by setting θ9 to 35 to 55 degrees, when the piezoelectric fiber 61 expands and contracts in the axial direction 101, the piezoelectric fiber 61 expands and contracts in an angle of 35 to 55 degrees with respect to the stretching direction 202 of the piezoelectric yarn 31. Therefore, power can be efficiently generated.

  FIGS. 7A to 7C are schematic cross-sectional views illustrating a modified example of the lower twisted yarn according to the first embodiment. In the lower twist yarn according to the modified example, the description of the same configuration as the lower twist yarn according to the first embodiment is omitted, and only different configurations will be described.

  As shown in FIG. 7A, the lower twist yarn 71 further includes an oil component 77 between the plurality of piezoelectric yarns 31. The oil 77 is attached so as to cover the piezoelectric yarn 31. Examples of the oil component 77 include olive oil, camellia oil, horse oil, and oil generally used as aroma oil. When such an oil is used, it has little effect on the skin and can be used safely.

  If staphylococci, bacteria such as Escherichia coli, or fungi such as trichophyton adhere to the piezoelectric thread, they may come off the piezoelectric thread before being sterilized by the piezoelectric thread. In this case, the separated bacteria and fungi may adhere to another object and propagate there.

  On the other hand, fungi easily adhere to the oil 77. By covering the piezoelectric yarn 31 with the oil 77, bacteria can be captured with the oil 77 on the surface of the lower twisted yarn 71. When bacteria adhere to the oil 77 covering the piezoelectric yarn 31, the bacteria attached to the oil 77 can be efficiently killed or weakened by the voltage generated by the expansion and contraction of the piezoelectric yarn 31. Thereby, antibacterial property can be improved.

  When the lower twisted yarn 71 is loosely twisted, a dense portion and a rough portion of the piezoelectric yarn 31 are formed inside. As a result, in the lower twisted yarn 71, a part where the generated electric charge is strong and a part where the charge is weak are generated. Even in the case where bacteria are attached to the oil portion 77 where the electric charge is not sufficiently generated, the bacteria are captured by the oil portion 77, so that if the piezoelectric yarn 31 moves later and a strong electric charge is generated, it is sure. Can be killed or weakened. In addition, as a position where the oil component 77 is attached, it may be attached to the entire length of the lower twisted yarn 71 in the longitudinal direction, or may be partially attached as needed.

  As shown in FIGS. 7B and 7C, in the lower twisted yarn 72 and the lower twisted yarn 73, it is not essential that the oil component 77 entirely covers the piezoelectric yarn 31. In this case, since the oil component 77 is not exposed on the surface, even an oil such as a mechanical oil, a silicone oil, or a liquid paraffin can be used. Further, in such a structure, since the oil 77 is not exposed to the surface, it is possible to prevent the oil 77 from adhering to the outside during use.

  As shown in FIG. 7C, in the lower twisted yarn 73, the arrangement of the plurality of piezoelectric yarns 31 is not uniform. The arrangement of the piezoelectric yarns 31 is such that the distance between the piezoelectric yarns 31 becomes smaller as approaching the center. Due to the capillary phenomenon, bacteria are easily attracted to the space where the distance between the central piezoelectric yarns 31 is reduced. Thereby, the bacteria can be more reliably captured. Therefore, the bacteria can be killed or weakened more efficiently.

  Note that, in the embodiment, the yarns forming the lower twist yarn and the covering yarn 63 may include a yarn (such as a cotton yarn) that does not generate an electric charge, other than the piezoelectric yarn 31. Normally, piezoelectric yarns have a poor touch compared to cotton yarns and the like, so that the skin may be irritated when worn by the user. For this reason, by partially using a yarn (such as cotton yarn) that does not generate electric charge in the lower twisting yarn and the covering yarn 63, the touch of the piezoelectric fiber is improved, and the irritation to the skin is reduced.

  In the embodiment, the piezoelectric yarns 31 constituting the lower twisted yarn and the covering yarn may have the same thickness or may have different thicknesses. The lower twisted yarn and the covering yarn may have the same thickness or may have different thicknesses. Thereby, properties such as strength and thickness of the piezoelectric fiber can be adjusted in use.

  Finally, the description of the present embodiment is illustrative in all aspects and should not be construed as limiting. The scope of the present invention is defined by the terms of the claims, rather than the embodiments described above. Furthermore, it is intended that the scope of the present invention includes all modifications within the meaning and scope equivalent to the claims.

11, 51: Piezoelectric fiber (twisted yarn)
21, 52, 71, 72, 73 ... lower twisted yarn 31 ... piezoelectric yarn 61 ... piezoelectric fiber 63 ... covering yarn

One embodiment of the present invention relates to a piezoelectric yarn having antibacterial properties.

  Conventionally, many proposals have been made for fiber materials having antibacterial properties (see Patent Documents 1 to 7).

Japanese Patent No. 3281640 JP-A-7-310284 Japanese Patent No. 316,992 Japanese Patent No. 1805853 JP-A-8-226078 JP-A-9-194304 JP 2004-300650 A

  However, none of the materials having antibacterial properties exhibited long-lasting effects.

  In addition, an antibacterial material may cause an allergic reaction due to a drug or the like.

Therefore, an object of one embodiment of the present invention is to provide a piezoelectric thread that has a longer effect than conventional materials having antibacterial properties and is safer than drugs and the like.

The piezoelectric yarn according to one embodiment of the present invention includes an upper twisted yarn further twisted from a plurality of lower twisted yarns that are twisted by turning a piezoelectric fiber made of a functional polymer that generates an electric charge by external energy. It is characterized by the following.

It has been known that the growth of bacteria and fungi can be suppressed by an electric field (for example, see Tetsuaki Doto, Hironori Korei, Hideaki Matsuoka, Junichi Koizumi, Kodansha: Microbial Control-Science and Engineering) Also, see, for example, Koichi Takagi, Application of High Voltage / Plasma Technology to Agriculture / Food, J. HTSJ, Vol.51, No.216). Further, depending on the potential generating the electric field, a current may flow through a current path formed by moisture or the like or a circuit formed by a local micro discharge phenomenon or the like. It is conceivable that this current weakens the bacteria and suppresses the growth of the bacteria. Since the piezoelectric yarn according to one embodiment of the present invention includes a plurality of charge generating fibers that generate electric charges by external energy, a predetermined electric potential (ground electric potential) between the fibers or between the fibers or the human body is used. An electric field is generated when it comes close to an object having Alternatively, when the piezoelectric yarn according to an embodiment of the present invention is close to an object having a predetermined potential (including a ground potential) such as a human body between fibers or a human body via moisture such as sweat. Current.

Therefore, the piezoelectric yarn according to one embodiment of the present invention exhibits an antibacterial effect for the following reasons. The direct action of an electric field or electric current generated when applied to an object (clothing, footwear, or a medical article such as a mask) used in close proximity to an object having a predetermined electric potential such as a human body, thereby causing a cell membrane of a bacterium or a bacterium to be generated. The electron transport system for maintaining the life of the bacterium is hindered, and the bacterium is killed or the bacterium itself is weakened. In addition, oxygen contained in water may be changed to reactive oxygen species by an electric field or electric current, or oxygen radicals may be generated in bacterial cells by a stress environment due to the presence of the electric field or electric current. Bacteria are killed or weakened by the action of reactive oxygen species including radicals. In some cases, the above reasons are combined to produce an antibacterial effect. The term “antibacterial” used in the present invention is a concept that includes both an effect of suppressing the occurrence of bacteria and an effect of killing bacteria.

  Note that the charge generation fiber that generates a charge by external energy may be, for example, a substance having a photoelectric effect, a substance having a pyroelectric effect, or a fiber using a piezoelectric body or the like. In addition, a structure in which an insulator is wound around the conductor using a conductor as the core yarn, and a voltage is applied to the conductor to generate charges, also constitutes a charge generation fiber.

  When a piezoelectric body is used, an electric field is generated by piezoelectricity, so that a power source is not required and there is no risk of electric shock. Further, the life of the piezoelectric body lasts longer than the antibacterial effect of a drug or the like. Also, the risk of allergic reactions is lower than that of drugs.

Furthermore, the piezoelectric yarn according to one embodiment of the present invention can have various variations in the piezoelectric yarn itself by adjusting the number of twists of the lower twisted yarn and the number of twists of the upper twisted yarn.

The piezoelectric yarn according to one embodiment of the present invention includes a covering yarn twisted by twisting a piezoelectric fiber made of a functional polymer that generates an electric charge by external energy, and the covering yarn is arranged in an axial direction. It is wound so that it turns.

The piezoelectric yarn according to one embodiment of the present invention can have various variations in the piezoelectric yarn itself by adjusting the number of twists of the lower twisted yarn and the number of windings of the covering yarn.

According to the present invention, it is possible to realize a piezoelectric yarn that has a longer effect than conventional materials having antibacterial properties and is more secure than drugs and the like.

FIG. 1A is a diagram showing the configuration of the upper twist yarn in the piezoelectric yarn according to the first embodiment, and FIG. 1B is a cross-sectional view of FIG. 1A. FIG. 2A is a partially enlarged view of FIG. 1A for explaining the configuration of the lower twist yarn in the piezoelectric yarn according to the first embodiment, and FIG. 2B is a diagram of FIG. FIG. FIGS. 3A and 3B are diagrams showing the relationship among the uniaxial stretching direction of polylactic acid, the electric field direction, and the deformation of the piezoelectric yarn . FIG. 4 illustrates the shear stress (shear stress) generated in each piezoelectric yarn when a tension is applied to the piezoelectric yarn . FIG. 5A is a diagram illustrating a configuration of an upper twisted yarn in the piezoelectric yarn according to the second embodiment, and FIG. 5B is a diagram illustrating a configuration of a lower twisted yarn in the piezoelectric yarn according to the second embodiment. FIG. 5 (A) is a partially enlarged view of FIG. FIG. 6A is a diagram illustrating a configuration of a covering yarn in the piezoelectric yarn according to the third embodiment, and FIG. 6B is a diagram illustrating a configuration of a twisted yarn in the piezoelectric yarn according to the third embodiment. FIG. 7 is a partially enlarged view of FIG. FIGS. 7A to 7C are schematic cross-sectional views illustrating a modified example of the lower twisted yarn according to the first embodiment.

FIG. 1A is a diagram showing a configuration of a top twisted yarn in the piezoelectric yarn according to the first embodiment, and FIG. 1B is a cross-sectional view of FIG. 1A cut along II. 1 (A) and 1 (B) show a piezoelectric yarn in which seven lower twisted yarns are twisted as an example, but the number of lower twisted yarns is not limited to this, and in practice It is set appropriately in consideration of the above.

As shown in FIGS. 1A and 1B, the piezoelectric yarn 11 includes an upper twisted yarn (multifilament yarn) formed by twisting a plurality of lower twisted yarns 21. The piezoelectric yarn 11 is a right-handed yarn (hereinafter, referred to as an S yarn) that is formed by twisting the lower twisted yarn 21 to the right.

In the piezoelectric yarn 11, the longitudinal direction 201 of the lower twist yarn 21 is inclined leftward with respect to the axial direction 101 of the piezoelectric yarn 11. The inclination of the angle of the lower twisting 21 relative to the axis direction 101 of the piezoelectric thread 11 is dependent on the twisting number of the piezoelectric thread 11.

In the piezoelectric thread 11, in accordance with the twist number increases, the angle of the longitudinal direction 201 of the lower twisted 21 at the outer peripheral portion of the piezoelectric thread 11 relative to the axis direction 101 of the piezoelectric yarn 11 is increased. Therefore, by adjusting the number of times the piezoelectric yarn 11 twisted, it is possible to adjust the inclination angle of the lower twisting 21 in the outer peripheral portion of the piezoelectric thread 11 with respect to the axis direction 101, the θ1 shown in FIG. 1 (A). For example, θ1 can be set to 10 to 25 degrees. By setting θ1 to 10 to 25 degrees, the piezoelectric yarn 11 can maintain an appropriate elasticity while stably maintaining the shape as the upper twist yarn, which is a bundle of the lower twist yarn 21.

FIG. 2A is an enlarged view of a region surrounded by a dashed circle A1 in FIG. 1A for describing the configuration of the lower twisted yarn in the piezoelectric yarn according to the first embodiment, and FIG. 2) is a cross-sectional view of FIG. 2 (A) obtained by cutting one lower twisted yarn along II-II.

As shown in FIGS. 2A and 2B, the lower twist yarn 21 includes a multifilament yarn formed by twisting a plurality of piezoelectric fibers 31. The lower twist yarn 21 is a right-turn yarn (hereinafter, referred to as an S yarn) which is twisted by turning the piezoelectric fiber 31 right. That is, the lower twisted yarn 21 is twisted in the same direction as the piezoelectric yarn 11 that is the upper twisted yarn.

The piezoelectric fiber 31 is an example of a charge generation fiber (charge generation yarn) that generates charges by external energy.

The piezoelectric fibers 31 are made of a functional polymer, for example, a piezoelectric polymer. Examples of the piezoelectric polymer include polylactic acid (PLA). Polylactic acid (PLA) is a piezoelectric polymer having no pyroelectricity. Polylactic acid generates piezoelectricity by being uniaxially stretched. Polylactic acid includes PLLA in which an L-form monomer is polymerized and PDLA in which a D-form monomer is polymerized. Note that the piezoelectric fiber 31 may further include a material other than the functional polymer as long as it does not impair the function of the functional polymer.

Polylactic acid is a chiral polymer, and the main chain has a helical structure. Polylactic acid develops piezoelectricity when molecules are oriented by uniaxial stretching. When the crystallinity is further increased by heat treatment, the piezoelectric constant increases. The piezoelectric fiber 31 made of uniaxially stretched polylactic acid has a thickness direction defined as a first axis, a stretching direction 202 defined as a third axis, and a direction orthogonal to both the first axis and the third axis defined as a second axis. having a tensor components of _{d 14} and _{d 25} as the piezoelectric strain constant. Therefore, polylactic acid generates electric charges most efficiently when distortion occurs in a direction of 45 degrees with respect to the uniaxially stretched direction.

FIGS. 3A and 3B are diagrams showing the relationship between the uniaxial stretching direction 202 of polylactic acid, the direction of the electric field, and the deformation of the piezoelectric fiber 31. As shown in FIG. 3A, when the piezoelectric fibers 31 contract in the direction of the first diagonal line 910A and extend in the direction of the second diagonal line 910B orthogonal to the first diagonal line 910A, the piezoelectric fibers 31 move in the direction from the back side of the paper to the front side. Generates an electric field. That is, the piezoelectric fiber 31 generates a negative charge on the front side of the drawing. As shown in FIG. 3B, when the piezoelectric fibers 31 extend in the direction of the first diagonal line 910A and contract in the direction of the second diagonal line 910B, they generate electric charges, but the polarity is reversed and the surface of the paper surface is reversed. An electric field is generated in the direction from the back to the back side. That is, the piezoelectric fiber 31 generates a positive charge on the front side of the drawing.

  Polylactic acid does not need to be subjected to a poling treatment unlike other piezoelectric polymers such as PVDF or piezoelectric ceramics, since piezoelectricity is generated by molecular orientation treatment by stretching. The uniaxially stretched polylactic acid has a piezoelectric constant of about 5 to 30 pC / N, and has a very high piezoelectric constant among polymers. Furthermore, the piezoelectric constant of polylactic acid does not fluctuate with time and is extremely stable.

The piezoelectric fiber 31 is a fiber having a circular cross section. The piezoelectric fibers 31 may be formed, for example, by extruding a piezoelectric polymer into fibers, or by melt-spinning the piezoelectric polymer into fibers (for example, a spinning / drawing method in which the spinning step and the drawing step are performed separately). Including the direct drawing method in which the spinning and drawing steps are connected, the POY-DTY method in which the false twisting step can be performed at the same time, and the ultra-high-speed prevention method in which the speed is increased.) Spinning (for example, a phase separation method or a dry-wet spinning method in which a raw material polymer is dissolved in a solvent and extruded from a nozzle to form fibers, a gel spinning method in which fibers are uniformly formed into a gel while containing a solvent, Or a liquid crystal spinning method of forming a fiber using a liquid crystal solution or a melt, or the like, or a method of forming a piezoelectric polymer into a fiber by electrostatic spinning. Note that the cross-sectional shape of the piezoelectric fiber 31 is not limited to a circle.

Similarly to the piezoelectric yarn 11, in the lower twisted yarn 21, the stretching direction 202 of the piezoelectric fiber 31 is inclined leftward with respect to the longitudinal direction 102 of the lower twisted yarn 21. The angle of the inclination of the piezoelectric fiber 31 with respect to the longitudinal direction 102 of the lower twisted yarn 21 depends on the number of twists of the lower twisted yarn 21. Therefore, by adjusting the number of twists of the lower twisted yarn 21, the angle of inclination of the piezoelectric fiber 31 at the outer peripheral portion of the piezoelectric fiber 31 with respect to the longitudinal direction 102, that is, θ2 shown in FIG. 2A can be adjusted. For example, θ2 can be set to 20 to 35 degrees. By setting θ2 to 20 to 35 degrees, the rigidity of the lower twisted yarn 21 can be maintained.

FIG. 4 illustrates the shear stress (shear stress) generated in each piezoelectric yarn when a tension is applied to the piezoelectric yarn . As shown in FIG. 4, when tension is applied to the piezoelectric thread 11, axial force 101 of the piezoelectric thread 11 is applied to the lower twine 21 constituting the piezoelectric thread 11. At this time, a force in the axial direction 101 of the piezoelectric yarn 11 is applied to the piezoelectric fibers 31 constituting the lower twisted yarn 21.

When tension is applied to the piezoelectric fiber 31 of the lower twist yarn 21 that is the S yarn, the surface of the piezoelectric fiber 31 is in a state as shown in FIG. Therefore, a negative charge is generated on the surface of the piezoelectric yarn 11 and a positive charge is generated on the inside.

The piezoelectric yarn 11 generates an electric field by a potential difference generated by the electric charge. This electric field leaks into the nearby space to form a coupling electric field with other parts. In addition, when the electric potential generated in the piezoelectric yarn 11 is close to an object having a predetermined electric potential close thereto, for example, a human body or the like having a predetermined electric potential (including a ground electric potential), an electric field is generated between the piezoelectric yarn 11 and the object. Cause.

  It is known that the growth of bacteria and fungi can be suppressed by an electric field (for example, see Tetsuaki Doto, Hironori Koma, Hideaki Matsuoka, Junichi Koizumi, Kodansha: Microbial Control-Science and Engineering). Also, see, for example, Koichi Takagi, Application of High Voltage and Plasma Technology to Agriculture and Food Fields, J.HTSJ, Vol.51, No.216). Further, depending on the potential generating the electric field, a current may flow through a current path formed by moisture or the like or a circuit formed by a local micro discharge phenomenon or the like. It is conceivable that this current weakens the bacteria and suppresses the growth of the bacteria. In addition, the bacteria referred to in the present embodiment include bacteria, fungi, and microorganisms such as mites and fleas.

Therefore, the piezoelectric yarn 11 directly exerts an antibacterial effect by an electric field formed in the vicinity of the piezoelectric yarn 11 or by an electric field generated when approaching an object having a predetermined potential such as a human body. Alternatively, the piezoelectric thread 11 allows a current to flow when approaching an object having a predetermined potential, such as another fiber or a human body, via moisture such as sweat. Even with this current, the antibacterial effect may be directly exerted. Alternatively, active oxygen species in which oxygen contained in water is changed by the action of electric current or voltage, radical species generated by interaction or catalysis with an additive contained in fiber, or other antibacterial chemical species (amine Derivatives, etc.) may exert an antimicrobial effect indirectly. Alternatively, oxygen radicals may be generated in the cells of the bacterium due to a stress environment due to the presence of an electric field or current, whereby the piezoelectric yarn 11 may exert an antibacterial effect indirectly. In addition, the left-handed yarn twisted by left-turning the piezoelectric fiber 31 can also exert the antibacterial effect directly or indirectly similarly to the piezoelectric yarn 11. As the radical, generation of a superoxide anion radical (active oxygen) or a hydroxyl radical is considered. The term “antibacterial” in the present embodiment is a concept that includes both an effect of suppressing the occurrence of bacteria and an effect of killing bacteria.

The angles θ1 and θ2 can be adjusted by adjusting the number of twists of the lower twisted yarn 21 and the number of twists of the piezoelectric yarn 11 that is the upper twisted yarn. In the first embodiment, the lower twisted yarn 21 is twisted such that the piezoelectric fibers 31 are at 45 degrees or less with respect to the longitudinal direction 102, and the piezoelectric yarn 11 that is the upper twisted yarn is oriented in the same direction as the lower twisted yarn 21. It is preferably twisted. Thereby, θ3, which is the sum of θ1 and θ2, can be adjusted.

Here, when the angle of θ1 with respect to θ2 is small, that is, when the number of twists of the piezoelectric yarn 11 is smaller than the number of twists of the lower twist yarn 21, the twist of the lower twist yarn 21 appearing on the surface is small, so that a soft touch can be obtained. . Conversely, when the angle of θ2 is smaller with respect to θ1, that is, when the number of twists of the piezoelectric yarn 11 is larger than the number of twists of the lower twist yarn 21, the lower twist yarn 21 appearing on the surface is more twisted. be able to. If the piezoelectric thread 11 is difficult to unwind, the piezoelectric thread 11 can obtain stable antibacterial properties.

θ3 is the angle of the stretching direction 202 of the piezoelectric fiber 31 at the outer peripheral portion of the lower twisted yarn 21 with respect to the axial direction 101 of the piezoelectric yarn 11 as shown in FIG. For example, θ3 can be set to 35 to 55 degrees. By setting the angle θ3 of the piezoelectric fiber 31 with respect to the axial direction 101 of the piezoelectric yarn 11 to 35 to 55 degrees, when the piezoelectric yarn 11 expands and contracts in the axial direction 101, the angle θ3 becomes 35 to 55 with respect to the stretching direction 202 of the piezoelectric fiber 31. Since it is expanded and contracted in the direction of the angle, power can be efficiently generated.

When only the piezoelectric fiber 31 is twisted so that the angle of the piezoelectric yarn 11 with respect to the axial direction 101 is 35 to 55 degrees, the number of twists of the piezoelectric fiber 31 becomes considerably large. As a result, a load is applied to the piezoelectric fiber 31 and the piezoelectric fiber 31 is easily cut, so that the durability of the piezoelectric yarn 11 may be weakened.

In the first embodiment, the lower twisted yarn 21 and the piezoelectric yarn 11 are both S yarns that are turned clockwise and twisted. However, the lower twisted yarn 21 and the piezoelectric yarn 11 are both turned leftward and twisted. (Hereinafter, referred to as a Z yarn). Thereby, the angle of the piezoelectric fiber 31 with respect to the axial direction 101 of the piezoelectric yarn 11 can be set to 35 to 55 degrees, and the same effect can be obtained.

The piezoelectric yarn 11 as described above can be applied to various kinds of clothing or products such as medical members. For example, the piezoelectric thread 11 may be an undergarment (especially a sock), an insole such as a towel, shoes and boots, sportswear in general, a hat, a bedding (including a futon, a mattress, a sheet, a pillow, a pillow cover, etc.), a toothbrush, a floss, Various filters (filters for water purifiers, air conditioners or air purifiers), stuffed animals, pet-related products (mats for pets, pet clothes, inner clothes for pets), various mat products (foot, hand, toilet seat, etc.) , Curtains, kitchen utensils (sponge or cloth, etc.), seats (seats for cars, trains, airplanes, etc.), cushioning materials for motorcycle helmets and their exterior materials, sofas, bandages, gauze, masks, sutures, doctors and patients Applicable to clothing, supporters, sanitary goods, sports equipment (wear and glove innerwear, or karate used in martial arts), or packaging materials It can be.

Of clothing, in particular, socks (or supporters) always expand and contract along joints due to movement such as walking, so that the piezoelectric yarn 11 generates electric charges at high frequency. In addition, socks absorb moisture such as sweat and serve as a breeding ground for the growth of bacteria. However, since the piezoelectric yarn 11 can suppress the growth of bacteria, it has a remarkable effect as a fungus control application for deodorization. Occurs.

Further, the piezoelectric thread 11 can also be used as a method of controlling bacteria on the body surface of an animal excluding a human, and a cloth including a piezoelectric body is arranged so as to face at least a part of the skin of the animal, The electric charge generated when an external force is applied to the piezoelectric body may suppress the growth of bacteria on the body surface of the animal facing the cloth. Thereby, it is possible to suppress the growth of bacteria on the body surface of an animal and to treat a skin disease derived from Trichophyton on the body surface of an animal in a simple manner, which is safer than the use of drugs and the like. it can.

In addition, the piezoelectric yarn of the present embodiment has the following uses in addition to the antibacterial use.

(1) Biologically acting piezoelectric fiber product Many tissues constituting a living body have piezoelectricity. For example, collagen constituting the human body is a kind of protein, and is contained in a large amount in blood vessels, dermis, ligaments, healthy, bone, cartilage and the like. Collagen is a piezoelectric body, and a tissue in which collagen is oriented may show very large piezoelectricity. Many reports have already been made on the piezoelectricity of bone (see, for example, Eiichi Fukada, Piezoelectricity of biopolymers, Polymer Vol. 16 (1967) No. 9 p795-800, etc.). Accordingly, when an electric field is generated by the piezoelectric yarn having the piezoelectric fibers 31 and the electric field alternates or the intensity of the electric field changes, the piezoelectric body of the living body vibrates due to the inverse piezoelectric effect. Due to the alternation of the alternating electric field or the electric field strength caused by the piezoelectric fibers 31, a minute vibration is applied to a part of the living body, for example, a capillary or a dermis, so that the blood flow in the part can be improved. This may promote healing of skin diseases and wounds. Therefore, the piezoelectric thread 11 functions as a bio-actuated piezoelectric fiber product.

(2) Piezoelectric Fiber Product for Adsorbing Substance As described above, the piezoelectric fiber 31 of the lower twist yarn 21 that is the S yarn generates a negative charge when an external force is applied. When the lower twist yarn 21 is a Z yarn, the piezoelectric fiber 31 generates a positive charge when an external force is applied. Therefore, the piezoelectric fiber 31 has a property of adsorbing a substance having a positive charge (for example, particles such as pollen) and adsorbing a substance having a negative charge (for example, a harmful substance such as yellow sand). Therefore, when applied to medical supplies such as a mask, the piezoelectric thread 11 having the piezoelectric fibers 31 can adsorb fine particles such as pollen and yellow sand.

  Note that a structure in which an insulator is wound around the conductor using a conductor as the core yarn and electric charge is generated by flowing electricity through the conductor is also a fiber that generates charge. However, since a piezoelectric body generates an electric field by piezoelectricity, a power source is not required and there is no risk of electric shock. Further, the life of the piezoelectric body lasts longer than the antibacterial effect of a drug or the like. Also, the risk of allergic reactions is lower than that of drugs. In addition, expression of resistant bacteria by drugs, particularly antibiotics, etc. has recently become a major problem, but it is unlikely that the sterilization method according to the present invention causes resistant bacteria due to the mechanism.

  In addition, as a fiber that generates a negative charge on the surface, a Z yarn using PDLA is also considered in addition to an S yarn using PLLA. Further, as a fiber that generates a positive charge on the surface, an S yarn using PDLA may be considered in addition to a Z yarn using PLLA.

FIG. 5A is a diagram illustrating a configuration of an upper twisted yarn in the piezoelectric yarn according to the second embodiment, and FIG. 5B is a diagram illustrating a configuration of a lower twisted yarn in the piezoelectric yarn according to the second embodiment. FIG. 6 is an enlarged view of a region surrounded by a dashed circle A2 in FIG. In the piezoelectric yarn according to the second embodiment, a description of the same configuration as the piezoelectric yarn according to the first embodiment will be omitted, and only different configurations will be described.

As shown in FIG. 5A, the piezoelectric yarn 51 according to the second embodiment includes an upper twisted yarn (multifilament yarn) formed by twisting a plurality of lower twisted yarns 52. The piezoelectric yarn 51 is a Z yarn that is formed by twisting the lower twisted yarn 52 counterclockwise.

In the piezoelectric yarn 51, the longitudinal direction 501 of the lower twist yarn 52 is inclined rightward with respect to the axial direction 101 of the piezoelectric yarn 51. By adjusting the number of twists of the lower twisted yarn 52, the angle of inclination of the lower twisted yarn 52 at the outer peripheral portion of the piezoelectric yarn 51 with respect to the axial direction 101, that is, θ4 shown in FIG. For example, θ4 can be set to 10 to 25 degrees. By setting θ4 to 10 to 25 degrees, the piezoelectric yarn 51 can stably maintain the shape of the upper twisted yarn, which is a bundle of the lower twisted yarn 52, and can maintain appropriate elasticity.

As shown in FIG. 5B, the lower twisted yarn 52 includes a multifilament yarn formed by twisting a plurality of piezoelectric fibers 31. The lower twisted yarn 52 is a Z yarn twisted by turning the piezoelectric fiber 31 counterclockwise. That is, the lower twisted yarn 52 is twisted in a different direction from the piezoelectric yarn 51 that is the upper twisted yarn. By being twisted in a direction different from that of the upper twisted yarn and the lower twisted yarn 52, the piezoelectric yarn 51 as a whole becomes stable and durable and has excellent durability. The same effect can be obtained even if the lower twisted yarn 52 is a Z yarn twisted by turning the piezoelectric fiber 31 counterclockwise, and the piezoelectric yarn 51 is an S yarn twisted by turning the lower twisted yarn 52 clockwise. Can be

By adjusting the number of twists of the lower twisted yarn 52, the inclination angle of the piezoelectric fiber 31 at the outer peripheral portion of the piezoelectric fiber 31 with respect to the longitudinal direction 501, that is, θ5 shown in FIG. 5B can be adjusted. For example, θ5 can be set to 55 to 70 degrees. By setting θ5 to 55 to 70 degrees, rigidity can be imparted to the lower twisted yarn 52.

In the second embodiment, the piezoelectric fibers 31 are preferably twisted so as to be at least 45 degrees with respect to the longitudinal direction 501 of the lower twisted yarn 52. Since the piezoelectric yarn 51 as the upper twist yarn is twisted in a different direction from the lower twist yarn 52, the angle θ6 of the piezoelectric fiber 31 with respect to the axial direction 101 of the piezoelectric yarn 51 is obtained by subtracting θ4 from θ5. This makes it possible to adjust θ6, which is the difference between θ4 and θ5. For example, θ6 can be set to 35 to 55 degrees. By setting the angle θ6 of the piezoelectric fiber 31 with respect to the axial direction 101 of the piezoelectric yarn 51 to 35 to 55 degrees, when the piezoelectric yarn 51 expands and contracts in the axial direction 101, the angle θ6 becomes 35 to 55 with respect to the stretching direction 202 of the piezoelectric fiber 31. Since it is expanded and contracted in the direction of the angle, power can be efficiently generated.

FIG. 6A is a diagram illustrating a configuration of a covering yarn in the piezoelectric yarn according to the third embodiment, and FIG. 6B is a diagram illustrating a configuration of a twisted yarn in the piezoelectric yarn according to the third embodiment. It is the figure which expanded the area | region enclosed with the broken-line circle A3 of FIG. 6 (A). In the piezoelectric yarn according to the third embodiment, description of the same configuration as that of the piezoelectric yarn according to the first embodiment will be omitted, and only different configurations will be described.

As shown in FIG. 6A, the piezoelectric yarn 61 according to the third embodiment includes a shaft 62 and a covering yarn 63. The covering thread 63 is wound around the shaft 62 so as to rotate with respect to an axis parallel to the axis direction 101 of the shaft 62. For example, the covering thread 63 is wound around the axis 62 while turning left. Thus, the shaft 62 has a property that the covering thread 63 does not have, so that a new property can be given to the piezoelectric thread 61. Note that the covering yarn 63 may be wound around the shaft 62 while turning rightward.

For example, as long as the material of the shaft 62 has elasticity, the elasticity can be imparted to the piezoelectric yarn even if the covering yarn 63 does not have elasticity. Note that the shaft 62 is not always necessary, and may be configured with only the covering thread 63.

The covering yarn 63 is wound at an angle θ7 with respect to an axis parallel to the axial direction 101 of the shaft 62. For example, θ7 can be set to 20 to 35 degrees. As shown in FIG. 6B, the covering yarn 63 is a Z yarn twisted by turning a plurality of piezoelectric fibers 31 counterclockwise. The piezoelectric fibers 31 are twisted at an angle θ8 with respect to the longitudinal direction 601 of the covering yarn 63.

By adjusting the number of twists of the covering yarn 63, the inclination angle of the piezoelectric fiber 31 at the outer peripheral portion of the piezoelectric fiber 31 with respect to the longitudinal direction 601 and θ8 shown in FIG. 6B can be adjusted. For example, θ8 can be set to 10 to 25 degrees. By setting θ8 to 10 to 25 degrees, the rigidity of the covering yarn 63 can be maintained.

In the third embodiment, it is preferable that the piezoelectric fibers 31 are twisted so as to be 45 degrees or less with respect to the longitudinal direction 601 of the covering yarn 63. In this case, since the piezoelectric yarn 61 is wound in the same direction as the covering yarn 63, the angle θ9 of the piezoelectric fiber 31 with respect to the axial direction 101 of the piezoelectric yarn 61 is obtained by adding θ8 to θ7. This makes it possible to adjust θ9, which is the sum of θ7 and θ8. For example, θ9 can be set to 35 to 55 degrees. By setting the angle θ9 of the piezoelectric fiber 31 with respect to the axial direction 101 of the piezoelectric yarn 61 to 35 to 55 degrees, when the piezoelectric yarn 61 expands and contracts in the axial direction 101, the angle θ9 becomes 35 to 55 with respect to the stretching direction 202 of the piezoelectric fiber 31. Since it is expanded and contracted in the direction of the angle, power can be efficiently generated.

In the third embodiment, the piezoelectric fibers 31 may be twisted so as to be at least 45 degrees with respect to the longitudinal direction 601 of the covering yarn 63. In this case, the piezoelectric yarn 61 needs to be wound in a different direction from the covering yarn 63. Although not shown, as in the second embodiment, the angle θ9 of the piezoelectric fiber 31 with respect to the axial direction 101 of the piezoelectric yarn 61 is obtained by subtracting θ7 from θ8. This makes it possible to adjust θ9, which is the difference between θ7 and θ8. Also in this case, by setting θ9 to 35 to 55 degrees, when the piezoelectric yarn 61 expands and contracts in the axial direction 101, the piezoelectric yarn 61 expands and contracts in an angle of 35 to 55 degrees with respect to the stretching direction 202 of the piezoelectric fiber 31. Therefore, power can be efficiently generated.

  FIGS. 7A to 7C are schematic cross-sectional views illustrating a modified example of the lower twisted yarn according to the first embodiment. In the lower twist yarn according to the modified example, the description of the same configuration as the lower twist yarn according to the first embodiment is omitted, and only different configurations will be described.

As shown in FIG. 7A, the lower twisted yarn 71 further includes an oil component 77 between the plurality of piezoelectric fibers 31. The oil component 77 is attached so as to cover the piezoelectric fibers 31. Examples of the oil component 77 include olive oil, camellia oil, horse oil, and oil generally used as aroma oil. When such an oil is used, it has little effect on the skin and can be used safely.

And Staphylococcus aureus, the fungi such as bacteria and Trichophyton such as Escherichia coli from adhering to the piezoelectric fibers, which may peel off from the piezoelectric fibers before being sterilized by the piezoelectric fibers. In this case, the separated bacteria and fungi may adhere to another object and propagate there.

On the other hand, fungi easily adhere to the oil 77. By covering the piezoelectric fiber 31 with the oil 77, it is possible to capture bacteria with the oil 77 on the surface of the lower twisted yarn 71. When bacteria adhere to the oil component 77 covering the piezoelectric fiber 31, the bacteria attached to the oil component 77 can be efficiently killed or weakened by the voltage generated by the expansion and contraction of the piezoelectric fiber 31. Thereby, antibacterial property can be improved.

When the lower twisted yarn 71 is loosely twisted, a dense portion and a rough portion of the piezoelectric fiber 31 are formed inside. As a result, in the lower twisted yarn 71, a part where the generated electric charge is strong and a part where the charge is weak are generated. Even in the case where bacteria are attached to the oil portion 77 where the electric charge is not sufficiently generated, the bacteria are captured by the oil portion 77, so that when the piezoelectric fiber 31 moves later and a strong electric charge is generated, it is surely. Can be killed or weakened. In addition, as a position where the oil component 77 is attached, it may be attached to the entire length of the lower twisted yarn 71 in the longitudinal direction, or may be partially attached as needed.

As shown in FIGS. 7B and 7C, in the lower twisted yarn 72 and the lower twisted yarn 73, it is not essential that the oil component 77 entirely covers the piezoelectric fibers 31. In this case, since the oil component 77 is not exposed on the surface, even an oil such as a mechanical oil, a silicone oil, or a liquid paraffin can be used. Further, in such a structure, since the oil 77 is not exposed to the surface, it is possible to prevent the oil 77 from adhering to the outside during use.

As shown in FIG. 7C, in the lower twisted yarn 73, the arrangement of the plurality of piezoelectric fibers 31 is not uniform. The arrangement of the piezoelectric fibers 31 is such that the distance between the piezoelectric fibers 31 becomes smaller as approaching the center. Due to the capillary phenomenon, bacteria are easily attracted to the space in which the distance between the central piezoelectric fibers 31 is reduced. Thereby, the bacteria can be more reliably captured. Therefore, the bacteria can be killed or weakened more efficiently.

In addition, in the embodiment, the yarn constituting the lower twist yarn and the covering yarn 63 may include a yarn (such as a cotton yarn) that does not generate an electric charge other than the piezoelectric fiber 31. Normally, piezoelectric yarns have a poor touch compared to cotton yarns and the like, so that the skin may be irritated when worn by the user. For this reason, by partially using a yarn (such as cotton yarn) that does not generate an electric charge in the lower twisting yarn and the covering yarn 63, the feel of the piezoelectric yarn is improved, and the irritation to the skin is reduced.

In the embodiment, the piezoelectric fibers 31 constituting the lower twisted yarn and the covering yarn may have the same thickness or may have different thicknesses. The lower twisted yarn and the covering yarn may have the same thickness or may have different thicknesses. Thereby, properties such as the strength and thickness of the piezoelectric yarn can be adjusted in use.

  Finally, the description of the present embodiment is illustrative in all aspects and should not be construed as limiting. The scope of the present invention is defined by the terms of the claims, rather than the embodiments described above. Furthermore, it is intended that the scope of the present invention includes all modifications within the meaning and scope equivalent to the claims.

11, 51: Piezoelectric yarn (upper twist yarn)
21, 52, 71, 72, 73 ... lower twisted yarn 31 ... piezoelectric fiber 61 ... piezoelectric yarn 63 ... covering yarn

Claims (8)

A plurality of lower twisted yarns twisted by twisting a piezoelectric yarn made of a functional polymer that generates electric charges by external energy are provided, and further twisted upper twisted yarns are provided.
Piezoelectric fibers. The lower twist yarn is twisted so as to be 45 degrees or less with respect to the longitudinal direction of the lower twist yarn,
The upper twisted yarn is twisted in the same direction as the lower twisted yarn,
The piezoelectric fiber according to claim 1. The lower twisted yarn is twisted so as to be 45 degrees or more with respect to the longitudinal direction of the lower twisted yarn,
The upper twisted yarn is twisted in a different direction from the lower twisted yarn,
The piezoelectric fiber according to claim 1. The direction of the piezoelectric yarn in the upper twist yarn forms an angle of 35 to 55 degrees with respect to the axial direction,
The piezoelectric fiber according to claim 1. A covering yarn twisted by twisting a piezoelectric yarn made of a functional polymer that generates electric charge by external energy,
The covering yarn is wound so as to pivot with respect to the axial direction,
Piezoelectric fibers. The piezoelectric yarn is twisted so as to be 45 degrees or less with respect to the longitudinal direction of the covering yarn,
The covering yarn is wound in the same direction as the turning direction of the piezoelectric yarn,
The piezoelectric fiber according to claim 5. The piezoelectric yarn is twisted so as to be at least 45 degrees with respect to the longitudinal direction of the covering yarn,
The covering yarn is wound in a direction different from a direction in which the piezoelectric yarn turns,
The piezoelectric fiber according to claim 5. The direction of the piezoelectric yarn forms an angle of 35 to 55 degrees with respect to the axial direction,
The piezoelectric fiber according to any one of claims 5 to 7.

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