WO2021106843A1

WO2021106843A1 - Yarn and fabric

Info

Publication number: WO2021106843A1
Application number: PCT/JP2020/043599
Authority: WO
Inventors: 辻　雅之; 貴子西浦; 英治田口; 宏和林
Original assignee: 株式会社村田製作所
Priority date: 2019-11-26
Filing date: 2020-11-24
Publication date: 2021-06-03
Also published as: CN219342438U; JP7131715B2; JPWO2021106843A1

Abstract

The present invention provides a yarn and fabric, each of which exhibits a higher antibacterial effect. A yarn (1, 1A, 2, 2A) is provided with a plurality of potential-generating fibers (10), which generate a potential by means of an external energy, and a surfactant (100) which adheres to the plurality of potential-generating fibers (10). In addition, the yarn (1, 1A, 2, 2A) is characterized by the non-uniform adhesion state of the surfactant (100).

Description

Thread and fabric

The present invention relates to a yarn provided with a potential generating fiber that generates an electric potential by energy from the outside, and a fabric provided with the yarn.

Patent Document 1 discloses a piezoelectric thread that generates an electric potential by external energy.

Japanese Patent No. 6292368

In the presence of moisture containing electrolytes such as sweat, an electric current flows between multiple piezoelectric threads. When an electric current flows, the generated potential disappears. Therefore, the electric field disappears.

Therefore, an object of the present invention is to provide a thread and a fabric that suppress the disappearance of an electric field more than before.

The thread of the present invention includes a plurality of electric potential generating fibers that generate electric potentials by energy from the outside, and a surfactant that adheres to the plurality of electric potential generating fibers. Further, the yarn is characterized in that the adhesion mode of the surfactant is not uniform.

Surfactant improves the wettability of the thread surface. Moisture spreads wet on the surface of the yarn and easily evaporates. In particular, when the adhesion mode of the surfactant is not uniform, the moisture is more likely to get wet and spread on the surface of the yarn than when it is uniform. Therefore, it becomes difficult for water to intervene between the plurality of potential generating fibers. Therefore, the thread of the present invention can easily maintain an electric field.

The thread of the present invention can suppress the disappearance of the electric field more than before.

FIG. 1 (A) is a diagram showing the configuration of the thread 1, and FIG. 1 (B) is a cross-sectional view taken along the line AA of FIG. 1 (A). 2 (A) and 2 (B) are views showing the relationship between the uniaxial stretching direction of polylactic acid, the electric field direction, and the deformation of the piezoelectric fiber 10. FIG. 3 is a diagram showing the configuration of the thread 2. It is a figure which shows the electric field in the thread 1 and the thread 2. It is a simulation result which shows the relationship between the amount of a surfactant and the water content after a lapse of a predetermined time. It is sectional drawing of the thread 1A which concerns on the modification. It is a figure which shows the cloth 75.

FIG. 1 (A) is a partially exploded view showing the configuration of the thread 1, and FIG. 1 (B) is a cross-sectional view taken along the line AA of FIG. 1 (A). The yarn 1 is a multifilament yarn in which a plurality of piezoelectric fibers 10 are twisted. Further, the thread 1 has a surfactant 100 attached to the plurality of piezoelectric fibers 10.

The piezoelectric fiber 10 is a fiber having a circular cross section. The yarn 1 is a left-handed swirl yarn (hereinafter, referred to as S yarn) in which a plurality of piezoelectric fibers 10 are swiveled to the left and twisted. In the present embodiment, as an example, the yarn 1 in which seven piezoelectric fibers 10 are twisted is shown, but the number of twists is actually set as appropriate in consideration of the intended use and the like.

The piezoelectric fiber 10 is made of, for example, a piezoelectric polymer. The piezoelectric fiber 10 is manufactured, for example, by a method of extruding a piezoelectric polymer into fibers. Alternatively, the piezoelectric fiber 10 is 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 direct drawing method in which a spinning step and a drawing step are connected, and false twisting. The POY-DTY method, which can be performed at the same time, or the ultra-high-speed spinning method for high speed, etc.), dry or wet spinning of piezoelectric polymers (for example, by dissolving the raw material polymer in a solvent) A phase separation method or a dry-wet spinning method in which fibers are extruded from a nozzle, a liquid crystal spinning method in which the fibers are uniformly fiberized into a gel while containing a solvent, or a liquid crystal spinning method in which fibers are formed using a liquid crystal solution or a melt. It is manufactured by a method of fiberizing by a method, etc.), or a method of fiberizing a piezoelectric polymer by electrostatic spinning. The cross-sectional shape of the piezoelectric fiber 10 is not limited to a circular shape.

Piezoelectric polymers include those having pyroelectricity and those not having pyroelectricity. The piezoelectric fiber 10 of the present embodiment may or may not have pyroelectricity. For example, PVDF (polyvinylidene fluoride) has pyroelectricity, and an electric potential is generated even when the temperature changes. Pyroelectric piezoelectric polymers such as PVDF also generate potentials due to the thermal energy of the human body. In this case, the heat energy of the human body is the energy from the outside.

Polylactic acid (PLA) is a piezoelectric polymer that does not have pyroelectricity. Polylactic acid is uniaxially stretched to produce piezoelectricity. Polylactic acid includes PLLA having a right-handed helical structure in which an L-form monomer is polymerized, and PDLA having a left-handed helical structure in which a D-monomer is polymerized and having a piezoelectric constant polarity opposite to that of PLLA.

2 (A) and 2 (B) show the uniaxially stretched direction, the electric field direction, and the piezoelectric fiber 10 of the thread 1 in the case where the piezoelectric fiber 10 is uniaxially stretched L-form polylactic acid. It is a figure which shows the relationship with the deformation of. Note that FIGS. 2 (A) and 2 (B) are views when the piezoelectric fiber 10 is assumed to have a film shape as a model case.

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. The uniaxially stretched piezoelectric fiber 10 made of polylactic acid is defined as the first axis in the thickness direction, the third axis in the stretching direction 900, and the second axis in the direction orthogonal to both the first axis and the third axis. It has tensor components _{of d 14} and d ₂₅ as piezoelectric strain constants. Therefore, the piezoelectric fiber 10 made of uniaxially stretched polylactic acid generates an electric potential when strain occurs in the direction of 45 degrees with respect to the uniaxially stretched direction.

As shown in FIG. 2A, the piezoelectric fiber 10 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, in the direction from the back side to the front side of the paper surface. Generates an electric field. That is, the piezoelectric fiber 10 generates a negative potential on the front side of the paper surface. As shown in FIG. 2B, the piezoelectric fiber 10 also generates an electric potential 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 surface of the paper surface. An electric field is generated in the direction from to the back side. That is, the piezoelectric fiber 10 generates a positive potential on the front side of the paper surface.

Polylactic acid does not need to be polled like other piezoelectric polymers such as PVDF or piezoelectric ceramics because piezoelectricity is generated by the orientation of molecules due to stretching. 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.

A case where the piezoelectric fiber 10 having the above properties is applied to the thread 1 of FIG. 1 (A) will be described. In FIG. 1A, the stretching direction 900 of each piezoelectric fiber 10 coincides with the axial direction of each piezoelectric fiber 10. By twisting the plurality of piezoelectric fibers 10, the drawing direction 900 of the piezoelectric fibers 10 is tilted 45 degrees to the left on the paper surface with respect to the axial direction of the yarn 1.

When the thread 1 which is such an S thread is stretched by applying an axial tension, the piezoelectric fiber 10 stretches along the axial direction of the thread 1 and contracts along the width direction of the thread 1. The axial direction of the thread 1 corresponds to the second diagonal line 910B in the example of FIG. 2A. As a result, the piezoelectric fiber 10 contracts in the direction corresponding to the first diagonal line 910A and extends in the direction corresponding to the second diagonal line 910B, as in the example shown in FIG. 2 (A). Therefore, a negative potential is generated on the surface of the piezoelectric fiber 10, and a positive potential is generated on the inside. That is, the piezoelectric fiber 10 generates an electric potential by energy from the outside.

Since the piezoelectric fiber 10 generates an electric potential when shear stress is applied, the inclination of the thread 1 with respect to the axial direction is not limited to 45 degrees to the left. The drawing direction 900 may intersect at least with respect to the axial direction of the yarn 1. That is, the drawing direction 900 of the piezoelectric fiber 10 may be greater than 0 degrees and less than 90 degrees to the left with respect to the axial direction of the yarn.

On the other hand, FIG. 3 is a partially exploded view showing the yarn 2 constituting the right-handed swivel yarn (hereinafter referred to as Z yarn) twisted by swirling the piezoelectric fiber 10 to the right. The thread 2 is a Z thread. By twisting the plurality of piezoelectric fibers 10, the drawing direction 900 of the piezoelectric fibers 10 is tilted 45 degrees to the right on the paper surface with respect to the axial direction of the yarn 2.

When the Z thread 2 is stretched by applying tension, the piezoelectric fiber 10 stretches along the axial direction of the thread 2 and contracts along the width direction of the thread 2. The axial direction of the thread 2 corresponds to the first diagonal line 910A in the example of FIG. 2B. As a result, the piezoelectric fiber 10 extends in the direction corresponding to the first diagonal line 910A and contracts in the direction corresponding to the second diagonal line 910B, as in the example shown in FIG. 2 (B). Therefore, a positive potential is generated on the surface of the piezoelectric fiber 10, and a negative potential is generated on the inside. That is, the piezoelectric fiber 10 generates an electric potential by energy from the outside. Since the piezoelectric fiber 10 generates an electric potential when shear stress is applied, the inclination of the thread 2 with respect to the axial direction is not limited to 45 degrees to the right, as long as it intersects at least the axial direction of the thread 2. Good. That is, the stretching direction 900 of the piezoelectric fiber 10 may be greater than 0 degrees and less than 90 degrees to the right with respect to the axial direction of the yarn 2.

FIG. 4 is a cross-sectional view showing the state of the electric field in the thread 1 and the thread 2. When the piezoelectric fibers 10 constituting the thread 1 and the thread 2 are formed of PLLA, the thread 1 alone has a negative potential on the surface and a positive potential inside when an axial tension is applied. With the thread 2 alone, when an axial tension is applied, the surface becomes a positive potential and the inside becomes a negative potential.

When these

threads

1 and 2 are close to each other, the adjacent parts (surfaces) tend to have the same potential. In this case, the proximity portion between the thread 1 and the thread 2 becomes 0 V, and the positive potential inside the thread 1 is further increased so as to maintain the original potential difference. Similarly, the negative potential inside the thread 2 becomes even lower.

In the cross section of the thread 1, an electric field is mainly formed from the inside to the outside of the thread 1, and in the cross section of the thread 2, an electric field is mainly formed from the outside to the inside. When the yarn 1 and the yarn 2 are brought close to each other, these electric fields leak into the air and are synthesized, and the electric field is formed between the yarn 1 and the yarn 2 due to the potential difference between the yarn 1 and the yarn 2. Alternatively, when the thread 1 and an object having a predetermined potential such as a human body are close to each other, an electric field is generated between the thread 1 and the object close to the thread 1. Even when the thread 2 and an object having a predetermined potential such as a human body are close to each other, an electric field is generated between the thread 2 and the object close to the thread 2.

Note that the thread 1 and the thread 2 do not have to have potentials having opposite polarities to each other. Even when the thread 1 and the thread 2 have potentials of the same polarity, an electric field is generated if there is a potential difference between them. That is, the thread 1 and the thread 2 may have different potentials when the potential is generated.

Such an electric field can suppress the growth of, for example, bacteria, fungi, archaea, or microorganisms such as mites and fleas.

Here, when the thread 1 or the thread 2 contains water containing an electrolyte, an electric current flows through the water. When an electric current flows, the potential generated in the thread 1 or the thread 2 disappears. When the electric potential disappears, so does the electric field.

The thread 1 or thread 2 of the present embodiment has a surfactant 100 attached to a plurality of piezoelectric fibers 10. The surfactant 100 may be ionic (cationic / anionic / zwitterionic) or nonionic (nonionic). Further, the surfactant 100 may be a small molecule or a polymer.

The surfactant 100 is, for example, an oil agent used in the fiber manufacturing process. When the user washes clothes containing thread 1 (or thread 2), the oil agent may be removed, but a laundry finishing agent (softener) may be attached instead. This softener is also an example of the surfactant 100.

The surfactant 100 improves the wettability of the surface of the piezoelectric fiber 10. Therefore, the water wets and spreads on the surface of the piezoelectric fiber 10. Moisture is exposed to the outside of the yarn by wetting and spreading on the fiber surface. Therefore, the moisture is more likely to evaporate and dries faster than when no surfactant is attached.

FIG. 5 is a simulation result showing the relationship between the amount of the surfactant and the water content after a lapse of a predetermined time. As shown in FIG. 5, as the amount of the surfactant increases, the water content after a lapse of a predetermined time decreases. That is, the larger the amount of the surfactant, the easier it is for the water to evaporate.

When the water evaporates, the current path disappears, so the potential of the thread 1 is easily maintained. In addition, the potential of the thread 2 is easily maintained. Therefore, the electric field formed between the yarn 1 and the yarn 2 is easily maintained.

The mode of attachment of the surfactant 100 to the plurality of piezoelectric fibers 10 in the present embodiment is not uniform. That is, the thread 1 (or thread 2) has a piezoelectric fiber 10 having a large amount of the surfactant 100 attached and a piezoelectric fiber 10 having a small amount of the surfactant 100 attached. More specifically, the surfactant 100 adhered by the piezoelectric fiber 10 arranged on the outside of the thread 1 (or thread 2) and the piezoelectric fiber 10 arranged on the inside of the thread 1 (or thread 2). The amount is different. For example, in the example of FIG. 1B, the amount of the surfactant 100 adhering to the piezoelectric fiber 10 arranged on the outside is larger than the amount of the surfactant 100 adhering to the piezoelectric fiber 10 arranged on the inside. ..

If the mode of attachment of the surfactant 100 to the plurality of piezoelectric fibers 10 is uniform, there is no bias in the wet spread of moisture. Thread 1 (or thread 2) is a multifilament thread. Therefore, the thread 1 or the thread 2 contains a large amount of surfactant inside. Therefore, a large amount of water is drawn into the thread 1 or the thread 2. Moisture drawn in is not exposed to the outside, so it is harder to dry than moisture that has spread to the outside. Since the thread 1 or the thread 2 also contains a surfactant on the outside, the thread 1 or the thread 2 is in a wet state as a whole.

On the other hand, if the mode of attachment of the surfactant 100 to the plurality of piezoelectric fibers 10 is not uniform, the wetting and spreading of water is biased. In particular, when the amount of the surfactant 100 adhering to the piezoelectric fiber 10 arranged on the outside is large, a large amount of water is exposed to the outside. Therefore, the water content is more likely to evaporate than when the surfactant 100 adheres in a uniform manner. Further, when the amount of the surfactant 100 adhering to the piezoelectric fiber 10 arranged on the outside is large, water is easily drawn into the inside of the yarn. In this case, the outside becomes dry. Therefore, the electric field formed between the yarn 1 and the yarn 2 is easily maintained.

Next, FIG. 6 is a cross-sectional view of the thread 1A according to a modified example of the thread 1. The thread 1A includes a resin 50 between the plurality of piezoelectric fibers 10. Resin 50 is an example of an insulator. In the cross section of FIG. 6, the resin 50 is arranged so as to coat the periphery of the piezoelectric fiber 10 arranged at the center and fill the gap with the surrounding piezoelectric fiber 10. Therefore, the surfactant 100 adheres more to the outside than the inside of the thread 1A.

Such a thread 1A adheres a large amount of surfactant 100 to the outside. Therefore, the water is more likely to evaporate. Therefore, the thread 1A can easily maintain the electric field. In addition, the resin 50 makes it difficult for moisture to enter the thread 1A. From this point as well, the thread 1A can easily maintain an electric field.

Although the modified example of the thread 1 is shown in FIG. 6, the thread 2A according to the modified example 2 provided with the resin 50 can be configured for the thread 2 as in the example of FIG.

The thread 1A may be a covering thread in which the piezoelectric fiber 10 is coated with the resin 50 and the coated piezoelectric fiber 10 is arranged as the core thread. In this case, the other plurality of piezoelectric fibers 10 rotate around the core yarn. The surfactant 100 adheres more to the outside than the inside of the thread 1A.

Further, the core thread may be a material to which the surfactant 100 does not easily adhere. Also in this case, the surfactant 100 adheres more to the outside than to the inside.

Further, the sheath yarn wound around the core yarn is not limited to the filament yarn, and may be a film-shaped piezoelectric material. Further, the filament yarn may be false twisted yarn. False plying has many gaps. Therefore, the surfactant 100 easily adheres to the false plying yarn. In addition, the false plying has a good texture.

Alternatively, the thread may have thick fibers on the inside and a plurality of thin piezoelectric fibers 10 on the outside. Also in this case, the surfactant 100 adheres more to the outside than to the inside.

Further, the amount of adhesion of the surfactant 100 on the inner side and the outer side of the hollow fiber or the thread having irregularities on the surface is different.

Further, the piezoelectric fibers constituting the yarn are not limited to long fibers, and may contain at least one short fiber. When the yarn is a spun yarn obtained by twisting a plurality of short fibers, the shape is more complicated than that of the long fibers. Therefore, the amount of the surfactant 100 adhered is not uniform. Also, the ends of some short fibers are exposed from the sides of the yarn. That is, more fibers are exposed on the surface of the yarn. Therefore, when short fibers are used, more surfactant adheres to the outside than to the inside.

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

The fabric 75 shown in FIG. 7 includes the yarn of the present embodiment described above. The fabric 75 containing the yarn shown in the present embodiment also easily maintains an electric field.

In addition, the applicant randomly extracted 10 threads from the fabric 75 and performed dynamic contact angle measurement (expansion / contraction method). In the 10 threads, the maximum value and the minimum value of the contact angle at the time of pulling up were ± 10 ° or more from the center value, respectively. Therefore, it can be seen that the adhesion mode of the surfactant is not uniform also for the cloth 75.

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.

1,1A, 2,2A ... Thread 10 ... Piezoelectric fiber 50 ... Resin 100 ... Surfactant 900 ... Stretching direction 910A ... First diagonal line 910B ... Second diagonal line

Claims

Multiple electric potential generating fibers that generate electric potential by external energy,
The surfactant adhering to the plurality of potential generating fibers and
With
The adhesion mode of the surfactant is not uniform.
yarn.
The amount of the surfactant adhering to the potential-generating fibers arranged on the outside and the potential-generating fibers arranged on the inside is different.
The thread according to claim 1.
The amount of surfactant adhering to the potential generating fibers arranged on the outside is larger than the amount of surfactant adhering to the potential generating fibers arranged on the inside.
The thread according to claim 2.
The plurality of potential generating fibers include at least two potential generating fibers having different potentials when the potential is generated.
The thread according to any one of claims 1 to 3.
An insulator arranged between the plurality of potential generating fibers.
The thread according to any one of claims 1 to 4.
The plurality of potential generating fibers contain polylactic acid.
The thread according to any one of claims 1 to 5.
A fabric containing the thread according to any one of claims 1 to 6.