WO2021125195A1

WO2021125195A1 - Spun yarn, and thread and fabric provided with same

Info

Publication number: WO2021125195A1
Application number: PCT/JP2020/046842
Authority: WO
Inventors: 健一郎宅見; 辻　雅之; 英治田口; 智晴木道
Original assignee: 株式会社村田製作所
Priority date: 2019-12-20
Filing date: 2020-12-16
Publication date: 2021-06-24
Also published as: CN114051543B; US20220267934A1; JPWO2021125195A1; JP7180792B2; CN114051543A

Abstract

This spun yarn is provided with a short fiber which is a piezoelectric fiber that generates a potential due to external energy, the spun yarn being characterized in that the short fiber includes a plurality of short fibers and is formed by twisting the plurality of short fibers together.

Description

Spun yarn, and yarns and fabrics with spun yarn

The present invention relates to a spun yarn that generates an electric charge, and a yarn and a cloth provided with the spun yarn.

Patent Document 1 discloses a thread having antibacterial properties. The yarn disclosed in Patent Document 1 includes a charge generating fiber that generates an electric charge by energy from the outside. The yarn disclosed in Patent Document 1 exhibits an antibacterial effect among a plurality of charge generating fibers by including a plurality of charge generating fibers having different polarities of the generated charges.

JP-A-2018-090950

When only the long fibers are strongly twisted, the voids between the long fibers become small. When the gap between the long fibers becomes small, the electric field is less likely to leak to the outside of the yarn, so that the antibacterial effect is reduced.

Therefore, an object of the present invention is to provide a spun yarn that efficiently exerts an antibacterial effect, and a yarn and a cloth provided with the spun yarn.

The spun yarn of the present invention includes short fibers that are piezoelectric fibers that generate an electric potential by external energy, and the short fibers include a plurality of short fibers, and the plurality of short fibers are twisted together. It is characterized by.

In the spun yarn according to the present invention, a plurality of short fibers are intricately intertwined with each other. When a plurality of short fibers are twisted together, each of the short fibers is swirled along various directions. That is, each of the short fibers follows a random direction with respect to the axial direction of the spun yarn.

When the spun yarn is stretched in the axial direction, each short fiber in the spun yarn is subjected to external forces such as tension, twisting, and bending in various directions with respect to the axial direction of each short fiber. Each short fiber generates charges of various sizes and polarities depending on the magnitude and direction of the applied external force. This allows the spun yarn to generate various and local electric fields between each short fiber. Therefore, the spun yarn according to the present invention can efficiently exert an antibacterial effect.

According to this invention, the antibacterial effect can be efficiently exhibited.

FIG. 1 (A) is a diagram showing a configuration of a spun yarn according to a first embodiment, and FIG. 1 (B) is a cross-sectional view taken along the line II of FIG. 1 (A). 2 (A) and 2 (B) are diagrams showing the relationship between the uniaxial stretching direction of the polylactic acid film, the electric field direction, and the deformation of the polylactic acid film. FIG. 3 illustrates the shear stress generated in each piezoelectric fiber when tension is applied to the spun yarn. FIG. 4 is a cross-sectional view schematically showing a part of the spun yarn for explaining the antibacterial mechanism in the spun yarn. FIG. 5 (A) is a diagram showing the configuration of the spun yarn according to the second embodiment, and FIG. 5 (B) is a cross-sectional view taken along the line II-II of FIG. 5 (A). FIG. 6 is a diagram showing the configuration of the spun yarn according to the third embodiment. FIG. 7A is a partially exploded view showing the structure of the antibacterial thread, and FIG. 7B is a cross-sectional view of the short fiber 111. FIG. 8 is a diagram showing the structure of the antibacterial cloth.

FIG. 1 (A) is a diagram showing the configuration of the spun yarn 10 according to the first embodiment, and FIG. 1 (B) is a cross-sectional view taken along the line II of FIG. 1 (A). In addition, in FIG. 1 (A) and FIG. 1 (B), the cross section of 7 yarns is shown as an example in the cross section of the line I-I, but the number of yarns constituting the spun yarn 10 is this. It is not limited, and is actually set as appropriate in consideration of the application and the like. Further, in FIG. 1B, only the cut surface cut along the line II is shown.

The spun yarn 10 includes a plurality of short fibers 11. The spun yarn 10 is formed by twisting a plurality of short fibers 11 together. The short fiber 11 is an example of a piezoelectric fiber that generates an electric charge due to external energy, for example, expansion and contraction.

The short fiber 11 is made of a functional polymer, for example, a piezoelectric polymer. Piezoelectric polymers include, for example, PVDF or polylactic acid (PLA). In addition, polylactic acid (PLA) is a piezoelectric polymer that does not have pyroelectricity. Polylactic acid is uniaxially stretched to produce piezoelectricity. Polylactic acid includes PLLA in which an L-form monomer is polymerized and PDLA in which a D-form monomer is polymerized. The short fiber 11 may further contain a fiber other than the functional polymer as long as it does not inhibit the function of the functional polymer.

Polylactic acid is a chiral polymer, and its main chain has a spiral structure. Polylactic acid exhibits piezoelectricity when it is uniaxially stretched and the molecules are oriented. Further heat treatment is applied to increase the crystallinity, thereby increasing the piezoelectric constant. When the thickness direction of the uniaxially stretched short fiber 11 made of polylactic acid is defined as the first axis, the stretching direction 900 is defined as the third axis, and the direction orthogonal to both the first axis and the third axis is defined as the second axis. It has tensor components _{of d 14} and d ₂₅ as piezoelectric strain constants. Therefore, polylactic acid most efficiently generates electric charges when strain occurs in the direction of 45 degrees with respect to the uniaxially stretched direction.

2 (A) and 2 (B) are diagrams showing the relationship between the uniaxial stretching direction of the polylactic acid film 200, the electric field direction, and the deformation of the polylactic acid film 200. 2 (A) and 2 (B) show a model case in which the short fiber 11 is assumed to have a film shape. As shown in FIG. 2A, the polylactic acid film 200 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, so that the polylactic acid film 200 faces from the back side to the front side of the paper surface. Generates an electric field in. That is, the polylactic acid film 200 generates a negative charge on the front side of the paper surface. As shown in FIG. 2B, the polylactic acid film 200 also generates an electric charge when it extends in the direction of the first diagonal line 910A and contracts in the direction of the second diagonal line 910B, but the polarity is reversed, and the polylactic acid film 200 is on the paper surface. An electric field is generated in the direction from the front side to the back side. That is, the polylactic acid film 200 generates a positive charge on the front side of the paper surface.

Since polylactic acid produces piezoelectricity by molecular orientation treatment by stretching, it is not necessary to perform polling treatment unlike other piezoelectric polymers such as PVDF or piezoelectric ceramics. The piezoelectric constant of uniaxially stretched polylactic acid is 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 short fiber 11 is a fiber having a circular cross section. The short fiber 11 is, for example, a method of extruding a piezoelectric polymer into fibers and a method of melt-spinning a piezoelectric polymer into fibers (for example, a spinning / drawing method in which a spinning step and a drawing step are performed separately. , A straight drawing method that connects the spinning process and the drawing process, a POY-DTY method that can also perform a false twisting process at the same time, or an ultra-high speed prevention method that aims to increase the speed), Dry or wet piezoelectric polymer Spinning (for example, a phase separation method or a dry-wet spinning method in which a polymer as a raw material is dissolved in a solvent and extruded from a nozzle to form fibers, or a gel spinning method in which fibers are uniformly fiberized in a gel state while containing a solvent. Alternatively, it is produced by a method of fiberizing by a liquid crystal spinning method (including a liquid crystal spinning method of fiberizing using a liquid crystal solution or a melt), or a method of fiberizing a piezoelectric polymer by electrostatic spinning. The cross-sectional shape of the short fiber 11 is not limited to a circular shape.

A string-shaped object such as a fiber has the smallest cross-sectional area when cut perpendicularly to the axial direction, and the cross-sectional area increases as the cut surface approaches parallel to the axial direction. As shown in FIG. 1B, the cross-sectional area of each short fiber 11 varies in the cross section perpendicular to the axial direction 101 of the spun yarn 10. This is because each short fiber 11 forms a random angle with respect to the axial direction 101 of the spun yarn 10.

The short fiber 11 is preferably 800 mm or less, more preferably 500 mm or less, or more preferably 300 mm or less, and further preferably 100 mm or less. As a result, as will be described in detail below, the short fibers 11 are easily exposed to the outside from the side surface of the spun yarn 10.

The fineness of the short fiber 11 is preferably 0.3 dtex or more and 10 dtex or less.

The cross-sectional shape of the short fiber 11 is not particularly limited, and may be, for example, a round cross section, a deformed cross section, a hollow, side-by-side, two or more layers, or a composite of these.

The spun yarn 10 is such a yarn formed by twisting a plurality of PLLA short fibers 11. The spun yarn 10 is a right-handed swirl yarn (hereinafter, referred to as S yarn) twisted by swirling the short fiber 11 to the right. The spun yarn 10 may be a left-handed swirl yarn (hereinafter, referred to as Z yarn) twisted by turning the short fiber 11 to the left.

Since the short fibers 11 are short, when a plurality of short fibers 11 are twisted, they are likely to be swiveled in random directions. That is, as shown in FIG. 1A, the axial direction of each short fiber 11 forms a random angle with respect to the axial direction 101 of the spun yarn 10. The spun yarn 10, that is, the plurality of short fibers 11, includes, for example, short fibers 111, short fibers 112, and short fibers 113. The short fiber 111 is an example of the first short fiber of the present invention, the short fiber 112 is an example of the second short fiber of the present invention, and the short fiber 113 is an example of the third short fiber of the present invention. ..

The short fiber 111 is tilted 0 degrees or more and 80 degrees or less, preferably 20 degrees or more and 50 degrees or less to the left with respect to the axial direction 101 of the spun yarn 10, and the short fiber 112 is 0 degrees to the left with respect to the axial direction 101 of the spun yarn 10. The short fiber 113 is tilted by 80 degrees or more, preferably 20 degrees or more and 50 degrees or less, and the short fiber 113 is tilted by 0 degrees or more and 80 degrees or less, preferably 20 degrees or more and 50 degrees or less with respect to the axial direction 101 of the spun yarn 10. The angles of the short fibers 111, the short fibers 112, and the short fibers 113 with respect to the axial direction 101 of the spun yarn 10 may be different from each other.

The short fibers 111 shown in FIG. 1A are those of the plurality of short fibers 11 that are aligned in a certain direction in the carding process. Therefore, the spun yarn 10 contains the most short fibers 111. The short fibers 111 may have different lengths in the range of 30 mm or more and 70 mm or less depending on the bias cut.

The short fiber 111, the short fiber 112, and the short fiber 113 each have a crimped portion 62. Note that FIG. 1A typically shows the crimped portion 62 of the short fiber 111. The short fibers 111 are restrained by the crimped portion 62. For example, the first end 71 side of the short fiber 111 in the longitudinal direction is constrained by the short fiber 112, and the second end 72 side of the short fiber 111 in the longitudinal direction is constrained by the short fiber 113. By restraining the first end 71 to the short fiber 112 and the second end 72 to the short fiber 113, the short fiber 111 can maintain a bundled state without being defibrated. This allows the user to efficiently transfer stress to the piezoelectric fibers.

The spun yarn 10 is manufactured by a method such as a ring, a compact, a silo ring, a silo compact, an air spinning, an air spinning, a mule, or a fryer, but the manufacturing method is not limited.

The short fibers 111, short fibers 112, and short fibers 113 are preferably 1st or higher and 500th or lower, respectively.

FIG. 3 illustrates the shear stress (shear stress) generated in each short fiber 11 when tension is applied to the axial direction 101 of the spun yarn 10.

As shown in FIG. 3, when an external force (tension) is applied to the axial direction 101 of the spun yarn 10, the short fibers 111 are in the state shown in FIG. 2 (A), and a negative charge is generated on the surface. Generates a positive charge on the inside. At the same time, the

short fibers

112 or 113 are in the state shown in FIG. 2A, and generate a negative charge on the surface and a positive charge on the inside. When the axial direction of the short fiber 112 or the short fiber 113 is 90 degrees different from the axial direction of the short fiber 111, the short fiber 112 or the short fiber 113 is in the state shown in FIG. 2 (B). As a result, a positive charge is generated on the surface and a negative charge is generated on the inside.

In this way, when an external force (tension) is applied to the spun yarn 10, the short fibers 111, the short fibers 112, and the short fibers 113 generate electric charges of different sizes on the surface. That is, since the orientation of each short fiber 11 is random, each short fiber 11 generates charges of various sizes and polarities. For example, when the short fibers 112 are oriented 90 degrees different from the axial direction of the short fibers 111, the first surface of the short fibers 111 faces the second surface of the short fibers 112 with the gap 41 interposed therebetween. Therefore, a strong electric field is locally generated in a narrow region between the short fibers 11 in the spun yarn 10. Further, even when the force for extending the spun yarn 10 in the axial direction 101 is small, electric fields can be generated because charges of various sizes and polarities are generated in the plurality of short fibers 11.

In the spun yarn 10, the plurality of short fibers 11 are each swirled along a random direction. Even if the plurality of short fibers 11 are strongly twisted, voids 41 are likely to occur between the plurality of short fibers 11. Further, since each short fiber 11 generates electric charges of various sizes and polarities, an electric field of various sizes is generated in the gap 41 between the short fibers 11. As a result, as described below, the antibacterial effect against the bacteria collected in the void 41 is improved.

FIG. 4 is a cross-sectional view schematically showing a part of the spun yarn 10 for explaining the antibacterial mechanism in the spun yarn 10. As shown in FIG. 4, the spun yarn 10 can absorb moisture 40 into the gaps 41 formed between the plurality of short fibers 11. The fine particles 42 such as bacteria absorbed by the spinning yarn 10 together with the water content 40 are easily retained inside the spinning yarn 10. Further, as the void 41 inside the spun yarn 10 becomes larger, the amount of water 40 that can be absorbed increases, so that the fine particles 42 held inside the spun yarn 10 also increase. As described above, the spun yarn 10 is excellent in the collection performance of the fine particles 42.

When the water content 40 in the spun yarn 10 evaporates after the spun yarn 10 collects the fine particles 42, the fine particles 42 remain in the voids 41 of the spun yarn 10. When the spun yarn 10 is stretched in the axial direction 101, the spun yarn 10 locally generates an electric field between the plurality of short fibers 11. Since the fine particles 42 are collected between the voids 41, that is, the plurality of short fibers 11, the fine particles 42 in the spun yarn 10 are exposed to a local and maximum electric field. Therefore, the spun yarn 10 can efficiently generate an antibacterial effect against bacteria and the like by the generated electric field.

Further, since the spun yarn 10 has many voids 41 between the plurality of short fibers 11, the electric field easily leaks to the outside of the spun yarn 10. When the spun yarn 10 is close to an object having a predetermined potential, for example, a human body or the like having a predetermined potential (including a ground potential), an electric field is generated between the spun yarn 10 and the object. In this way, the spun yarn 10 exerts an antibacterial effect even with other materials having a predetermined potential.

It has long been known that electric fields can suppress the growth of bacteria and fungi (see, for example, Tetsuaki Doto, Hiroki Korai, Hideaki Matsuoka, Junichi Koizumi, Kodansha: Microbial Control-Science and Engineering. Also, see, for example, Koichi Takaki, Application of high-voltage / plasma technology to the agricultural / food field, J.HTSJ, Vol.51, No.216). Further, depending on the potential that generates this electric field, a current may flow through a current path formed by humidity or the like, or a circuit formed by a local micro discharge phenomenon or the like. It is considered that this current weakens the bacteria and suppresses the growth of the bacteria. The bacteria referred to in the present embodiment include bacteria, fungi, and microorganisms such as mites and fleas.

Therefore, the spun yarn 10 exerts an antibacterial effect directly by the electric field formed inside the spun yarn 10 or by the electric field generated when the spun yarn 10 is close to an object having a predetermined potential such as a human body. Alternatively, the spun yarn 10 passes an electric current through moisture such as sweat when it is close to an object having a predetermined potential such as another fiber inside or adjacent to the human body. This current may also directly exert an antibacterial effect. Alternatively, reactive oxygen species in which oxygen contained in water is changed by the action of current or voltage, radical species generated by interaction or catalysis with additives contained in fibers, or other antibacterial chemical species (amines). Derivatives, etc.) may indirectly exert an antibacterial effect. Alternatively, oxygen radicals may be generated in the cells of the bacterium due to the stress environment due to the presence of an electric field or an electric current, whereby the spun yarn 10 may indirectly exert an antibacterial effect. As the radical, generation of superoxide anion radical (active oxygen) or hydroxyl radical can be considered. The term "antibacterial" as used in the present embodiment is a concept including both an effect of suppressing the growth of bacteria and an effect of killing the bacteria.

Since the spun yarn 10 uses a piezoelectric fiber that generates an electric charge by expansion and contraction, a power source is not required and there is no risk of electric shock. The life of the piezoelectric fiber lasts longer than the antibacterial effect of chemicals and the like. Also, piezoelectric fibers are less likely to cause an allergic reaction than drugs.

In the spun yarn 10, each short fiber 11 is interrupted in the spun yarn 10 in the middle of the axial direction 101 of the spun yarn 10. The ends of the short fibers 11 (for example, the first end 71 and the second end 72 shown in FIGS. 1A and 1B) are exposed from the side surface of the spun yarn 10 to the periphery. Since the ends of a large number of short fibers 11 are exposed on the side surface of the spun yarn 10, the side surface of the spun yarn 10 has a so-called fluffy structure. Thereby, the spun yarn 10 can adjust the feel and appearance. Further, since the surface area of the spun yarn 10 increases due to fluffing, moisture and fine particles are easily adsorbed on the side surface of the spun yarn 10. As a result, the spun yarn 10 is excellent in collecting fine particles and can efficiently generate an antibacterial effect.

The short fiber 11 may be crimped over the entire longitudinal direction. Since the crimped short fibers 11 have a complicated shape, they tend to be intricately entangled with each other. Therefore, when an external force (tension) is applied to the spun yarn 10, pulling, twisting, and bending forces in various directions are applied to each short fiber 11. Therefore, since each short fiber 11 generates electric charges of various sizes, various electric fields can be generated between the short fibers 11.

The number of crimps of the short fiber 11 is preferably 0 pieces / inch or more and 20 pieces / inch or less, and the crimp size (crimp ratio) is preferably 0% or more and 20% or less.

Further, when the spun yarn 10 contains the plurality of crimped short fibers 11, the voids 41 generated between the plurality of short fibers 11 are formed in the spun yarn 10 as compared with the case where the spun yarn 10 contains the plurality of uncrimped short fibers 11. growing. As a result, the antibacterial effect of the spun yarn 10 is improved as compared with the case where the plurality of short fibers 11 that are not crimped are included.

As described above, in the carding process, some of the short fibers 111 among the plurality of short fibers 11 are aligned in a certain direction. The short fibers 111 aligned in a certain direction are twisted in the spinning process to rotate left at 45 degrees to the left with respect to the axial direction 101 of the spun yarn 10. The greater the proportion of the short fibers 111 aligned in a certain direction in the carding process among the plurality of short fibers 11, the greater the proportion of the short fibers 111 along the same direction in the spun yarn 10. When the spun yarn 10 has many short fibers 111 that are swiveled at an angle of 45 degrees to the left, a negative charge is generated on the surface of the spun yarn 10 as a whole. In this way, by changing the ratio of the short fibers 111 in the spun yarn 10 in the carding step, the polarity of the electric charge generated on the surface of the spun yarn 10 can be controlled.

The axial angle of the short fibers 111 with respect to the axial direction 101 of the spun yarn 10 can be changed by the number of twists of the spun yarn 10. As the number of twists of the spun yarn 10 increases, the angle of inclination of the short fiber 111 in the drawing direction 900 with respect to the axial direction 101 of the spun yarn 10 increases.

The thickness of each short fiber 11 may be the same or different. Further, the thickness of each short fiber 11 does not necessarily have to be uniform.

As the yarn that generates a negative charge on the surface, in addition to the S yarn using PLLA, the Z yarn using PDLA can be considered. Further, as the yarn that generates a positive charge on the surface, in addition to the Z yarn using PLLA, the S yarn using PDLA can be considered.

Hereinafter, the spun yarn 50 according to the second embodiment will be described. FIG. 5 (A) is a diagram showing the configuration of the spun yarn 50 according to the second embodiment, and FIG. 5 (B) is a cross-sectional view of the spun yarn 50 in line II-II of FIG. 5 (A). .. FIG. 5A shows the short fibers 11 by hatching. In the description of the spun yarn 50, only the points different from those of the first embodiment will be described, and the same points will be omitted.

The spun yarn 50 includes a plurality of short fibers 11 which are piezoelectric fibers and a plurality of short fibers 51 which are ordinary fibers. In this example, the short fiber 111 in the first embodiment is the short fiber 11, and the short fiber 112 and the short fiber 113 in the first embodiment are the short fiber 51. Ordinary fibers are non-piezoelectric threads. Examples of ordinary fibers include natural fibers such as cotton and linen, animal fibers such as animal hair or silk, chemical fibers such as polyester and polyurethane, regenerated fibers such as rayon and cupra, semi-synthetic fibers such as acetate, or these. Examples include twisted yarn that is twisted. The strength and the degree of expansion and contraction of the spun yarn 50 can be adjusted according to the usage mode by selecting the material of the short fiber 51.

The ordinary fiber, which is the material of the short fiber 51, is preferably made of a material having higher hydrophilicity than the piezoelectric fiber, which is the short fiber 11. That is, the short fibers 112 and the short fibers 113 are made of a material having a higher hydrophilicity than the PLLA constituting the short fibers 111. Therefore, the spun yarn 50 is more hydrophilic than the spun yarn made of PLLA alone. When the hydrophilicity of the spun yarn 50 becomes high, moisture easily permeates into the inside of the spun yarn 50. Therefore, the collection performance of the spun yarn 50 is improved, and moisture and fine particles are easily adsorbed on the side surface of the spun yarn 50 and the voids 41.

When moisture enters the void 41 of the spun yarn 50, the spun yarn 50 swells. On the contrary, when the water vaporizes and is discharged to the outside from the void 41 of the spun yarn 50, the spun yarn 50 contracts. When the spun yarn 10 swells or contracts, each short fiber 11 inside the spun yarn 50 expands and contracts. Since each short fiber 11 expands and contracts, a local electric field is generated inside the spun yarn 50. Bacteria taken into the inside of the spun yarn 50 are killed or inactivated by an electric field. Therefore, the spun yarn 50 has a larger specific surface area than a yarn made only of long fibers, is excellent in collecting fine particles, and has an efficient antibacterial effect against bacteria and the like due to the electric charge generated by each short fiber 11. Can be generated.

Hereinafter, the spun yarn 60 according to the third embodiment will be described. FIG. 6 is a diagram showing the configuration of the spun yarn 60. In the description of the spun yarn 60, only the points different from the spun yarn 10 of the first embodiment will be described, and the same points will be omitted.

As shown in FIG. 6, the spun yarn 60 includes short fibers 111 and short fibers 61. The short fibers 61 are shorter than the short fibers 111. The

short fibers

111 and 61 are twisted together. Since the short fibers 111 are long, they are swiveled in a direction relatively identical to the axial direction 101 of the spun yarn 60. Since most of the short fibers 111 are tilted to the left with respect to the axial direction 101 of the spun yarn 60, most of the short fibers 111 are negative on the surface when stretched in the axial direction 101 of the spun yarn 60. Generates an electric charge. On the other hand, since the short fibers 61 are short, those that are swirled along a random direction with respect to the axial direction 101 of the spun yarn 60 are also included. Therefore, since the short fibers 61 include many fibers that are tilted to the right with respect to the axial direction 101 of the spun yarn 60 as compared with the short fibers 111, the short fibers 61 are stretched in the axial direction 101 of the spun yarn 60. 61 includes a part that generates a positive charge on the surface. Therefore, the spun yarn 60 can locally generate an electric field between the short fibers 111 and the short fibers 61. As the spun yarn 60, an example of two types of short fibers including short fibers 111 and short fibers 61 has been given, but the length of the short fibers is not limited to two types, and includes three or more types of short fibers. You may be.

Hereinafter, the antibacterial thread 70 will be described. FIG. 7A is a partially exploded view showing the structure of the antibacterial thread, and FIG. 7B is a cross-sectional view of the short fiber 111.

As shown in FIG. 7A, the antibacterial yarn 70 includes a spun yarn 10 and a spun yarn 20. The antibacterial yarn 70 is a yarn (Z yarn) in which the spun yarn 10 and the spun yarn 20 are twisted by turning left with each other.

In the antibacterial yarn 70, the spun yarn 10 contains a large amount of short fibers 111 that are swirled at an angle of 0 degrees or more and 80 degrees or less, preferably 20 degrees or more and 50 degrees or less to the left, and when stretched, the spun yarn 10 as a whole Generates a negative charge on the surface. The spun yarn 20 is a left-handed swirl yarn (Z yarn) twisted by turning the short fiber 11 to the left. The spun yarn 20 contains a large number of short fibers that are swirled at an angle of 0 degrees or more and 80 degrees or less, preferably 20 degrees or more and 50 degrees or less to the right, and when stretched, the spun yarn 20 as a whole has a positive charge on the surface. Produces.

In the spun yarn 10 and the spun yarn 20, the inclination of the short fiber 11 in the drawing direction 900 with respect to the axial direction 101 can be adjusted by the number of twists of the spun yarn 10, the spun yarn 20, and the antibacterial yarn 70. The number of twists of the antibacterial yarn 70 is preferably less than the number of twists of the spun yarn 10 and the spun yarn 20. For example, it is preferable that the drawing direction 900 of each short fiber 11 is finally adjusted so as to be tilted 45 degrees with respect to the axial direction 103 of the antibacterial thread 70. As a result, when the antibacterial thread 70 is stretched with respect to the axial direction 103 of the antibacterial thread 70, each short fiber 11 can effectively generate an electric charge.

The spun yarn 20 is a Z yarn using PLLA, but the spun yarn 20 may be an S yarn using PDLA. Since the spun yarn 10 and the spun yarn 20 are the same S yarn, the angle between the yarns can be easily adjusted when the antibacterial yarn 70 is manufactured. The spun yarn 10 may be a Z yarn using PDLA. In this case, since the spun yarn 10 and the spun yarn 20 are the same Z yarn, the angle between the yarns can be easily adjusted when the antibacterial yarn 70 is manufactured.

In the antibacterial yarn 70, since the spun yarn 10 that generates a negative charge on the surface and the spun yarn 20 that generates a positive charge on the surface are twisted together, a strong electric field can be generated by the antibacterial yarn 70 alone. In each of the spun yarn 10 and the spun yarn 20, the electric field formed between the inside and the surface of the spun yarn 10 or the spun yarn 20 leaks into the air. The electric fields generated by the spun yarn 10 and the spun yarn 20 are coupled to each other. A strong electric field is formed in the vicinity of the spun yarn 10 and the spun yarn 20, and the antibacterial yarn 70 exerts an antibacterial effect.

The structure of the twisted yarn is complicated, and the proximity points of the spun yarn 10 and the spun yarn 20 are not uniform. Further, when tension is applied to the spun yarn 10 or the spun yarn 20, the proximity portion also changes. As a result, the strength of the electric field changes in each part, and an electric field in which the symmetry shape is broken is generated. Similarly, a yarn (S yarn) in which the spun yarn 10 and the spun yarn 20 are turned to the right and twisted can also generate an electric field by itself. The number of twists of the spun yarn 10 and the number of twists of the spun yarn 20 or the number of twists of the antibacterial yarn 70 obtained by twisting these yarns are determined in consideration of the antibacterial effect.

The plurality of short fibers 11 constituting the spun yarn described above have a portion where the short fibers 11 come into contact with each other. In the short fibers 11 that are in contact with each other, the coefficient of static friction of one short fiber 11 is designed to be higher than the coefficient of static friction of the other short fiber 11. For example, the coefficient of static friction of the short fibers 111 is higher than the coefficient of static friction of the

short fibers

112 and 113. As a result, the relative movement of the short fibers 11 in contact with each other can be suppressed, and the short fibers 11 can efficiently apply shear stress to the spun yarn 10.

Further, as shown in FIG. 7B, the short fiber 111 of the short fibers 11 is a modified cross-section yarn. At least one of the short fibers 111, the short fibers 112, and the short fibers 113 that come into contact with each other may be irregular cross-section yarns, or all of them may be irregular cross-section yarns. The irregular cross-section yarn is a yarn having a cross section such as a cross, a star polygon, or a concave polygon. In any of the examples, the deformed cross-section yarn has a groove or a protrusion extending in the longitudinal direction of the deformed cross-section yarn. Here, the deformed cross-section yarn may have both a groove portion and a convex protrusion portion. For example, the short fiber 111 has a groove portion 74 and a convex protrusion portion 75. This makes it easier for the short fibers 11 to be entangled with each other, and the short fibers 11 can efficiently apply shear stress to the spun yarn 10.

The antibacterial cloth 80 will be described below. FIG. 8 is a diagram showing the configuration of the antibacterial cloth 80.

As shown in FIG. 8, the antibacterial cloth 80 includes a plurality of spun yarns 10 and a plurality of spun yarns 20. Since the spun yarn 10 and the spun yarn 20 are the same as those described in the antibacterial yarn 70, the description thereof will be omitted.

In the antibacterial cloth 80, the parts other than the spun yarn 10 and the spun yarn 20 are non-piezoelectric fibers. Here, the non-piezoelectric fiber includes a fiber which is made of a natural fiber such as cotton or wool or a synthetic fiber which is generally used as a yarn and does not generate an electric charge. The non-piezoelectric fiber may include a fiber that generates a weaker electric charge as compared with the spun yarn 10 and the spun yarn 20. In the antibacterial cloth 80, the spun yarn 10 and the spun yarn 20 are woven together with the non-piezoelectric fibers in a state of being arranged side by side alternately in parallel.

In the antibacterial cloth 80, the warp yarn is the spun yarn 10, the spun yarn 20, and the non-piezoelectric fiber, and the weft is the non-piezoelectric fiber. It is not always necessary to weave non-piezoelectric fibers into the warp yarns, and only the spun yarn 10 and the spun yarn 20 may be used. Further, the weft yarn is not limited to the non-piezoelectric fiber, and may include a spun yarn 10 or a spun yarn 20.

When the antibacterial cloth 80 is stretched in the direction parallel to the warp yarn, electric charges are generated from the spun yarn 10 and the spun yarn 20. In each of the spun yarn 10 and the spun yarn 20, the electric field formed between the inside and the surface of the yarn leaks into the air. The electric fields generated by the spun yarn 10 and the spun yarn 20 are coupled to each other. A strong electric field is formed in the vicinity of the spun yarn 10 and the spun yarn 20. As a result, the antibacterial cloth 80 exerts an antibacterial effect.

In the antibacterial cloth 80, the surfaces of the spun yarn 10 and the spun yarn 20 are fluffy. The contact area between the spun yarn 10, the spun yarn 20, and the non-piezoelectric fibers is larger than that in the case where the spun yarn 10 and the spun yarn 20 are not fluffed. Therefore, when the antibacterial cloth 80 is stretched, even if the antibacterial cloth 80 is not fully stretched, the spun yarn 10 and the spun yarn 20 are pulled. Therefore, even when the load applied to the antibacterial cloth 80 is small, the antibacterial cloth 80 can generate an electric field.

The antibacterial cloth 80 is not limited to the woven fabric. Examples of the antibacterial cloth 80 include a knitted fabric knitted using the spun yarn 10 and the spun yarn 20 as the knitting yarn, a non-woven fabric provided with the spun yarn 10 and the spun yarn 20 and the like.

The above-mentioned spun yarn 10, spun yarn 20, spun yarn 50, spun yarn 60, antibacterial yarn 70, or antibacterial cloth 80 can be applied to various clothing or products such as medical materials. For example, the spun yarn 10, the spun yarn 20, the spun yarn 50, the spun yarn 60, the antibacterial yarn 70, or the antibacterial cloth 80 is a mask, underwear (particularly socks), an inlay for towels, shoes, boots, etc., sportswear in general, and a hat. , Bedding (including duvets, mattresses, sheets, pillows, pillowcases, etc.), toothbrushes, floss, water purifiers, air purifier filters, etc., stuffed animals, pet-related products (pet mats, pet clothes, pets, etc.) Inner clothes), various mats (feet, hands, toilet seats, etc.), curtains, kitchen utensils (sponge or cloth, etc.), seats (seats for cars, trains, airplanes, etc.), cushioning materials for motorcycle helmets and theirs. Exterior materials, sofas, bandages, gauze, sutures, clothes for doctors and patients, supporters, sanitary goods, sports goods (inners for clothing and gloves, baskets used in martial arts, etc.), air conditioners or air purifiers, etc. It can be applied to filters, packaging materials, net doors, etc.

Finally, the description of this embodiment should be considered to be exemplary in all respects and not restrictive. The scope of the present invention is shown not by the above-described embodiment but by the scope of claims. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and scope equivalent to the claims.

10, 20, 50, 60 ...

Spinned yarn

11, 51, 61 ... Short fiber 70 ... Antibacterial yarn 80 ... Antibacterial cloth 111 ... First short fiber 112 ... Second short fiber 113 ... Third short fiber

Claims

Contains a first short fiber that generates an electric potential with external energy,
Spinned yarn.
Further equipped with a second short fiber and a third short fiber,
The first end side of the first short fiber in the longitudinal direction is constrained by the second short fiber, and the second end side of the first short fiber in the longitudinal direction is constrained by the third short fiber. ,
The spun yarn according to claim 1.
The second short fiber or the third short fiber has a higher coefficient of static friction than the first short fiber.
The spun yarn according to claim 2.
The first short fiber, the second short fiber, and the third short fiber have a crimped portion.
The first short fiber is constrained by the crimped portion.
The spun yarn according to claim 2 or 3.
The first short fiber is inclined with respect to the axial direction of the spun yarn.
The spun yarn according to any one of claims 1 to 4.
The angle of the first short fiber with respect to the axial direction of the spun yarn is 0 degrees or more and 80 degrees or less.
The spun yarn according to claim 5.
The angle of the first short fiber with respect to the axial direction of the spun yarn is 20 degrees or more and 50 degrees or less.
The spun yarn according to claim 6.
The fineness of the first short fiber, the second short fiber, and the third short fiber is 0.3 dtex or more and 10 dtex or less.
The spun yarn according to any one of claims 2 to 7.
The length of the first short fiber, the second short fiber, and the third short fiber is 10 mm or more and 800 mm or less.
The spun yarn according to any one of claims 2 to 8.
The first short fiber, the second short fiber, and the third short fiber are 1st to 500th.
The spun yarn according to any one of claims 2 to 9.
The first short fiber, the second short fiber, and the third short fiber include a plurality of short fibers having different lengths.
The spun yarn according to any one of claims 2 to 10.
The second short fiber and the third short fiber are ordinary fibers.
The spun yarn according to any one of claims 2 to 11.
The second short fiber and the third short fiber are made of a material having a higher hydrophilicity than the first short fiber.
The spun yarn according to claim 12.
The first short fiber is a piezoelectric fiber and contains a chiral polymer.
The spun yarn according to any one of claims 1 to 13.
The chiral polymer is polylactic acid,
The spun yarn according to claim 14.
At least one of the first short fiber, the second short fiber, and the third short fiber is the first short fiber, the second short fiber, and the third short fiber. Has a groove or protrusion extending in the longitudinal direction of the
The spun yarn according to any one of claims 2 to 15.
A plurality of spun yarns according to any one of claims 1 to 16 are provided.
The spun yarn includes right-twisted and left-twisted yarns.
yarn.
The spun yarn according to any one of claims 1 to 16.
cloth.