JP2024052117A - Fabrics and Textiles - Google Patents

Abstract

[Problem] To provide a cloth and a textile product capable of generating a surface potential more appropriately for a cloth with a relatively low elongation rate. [Solution] The cloth disclosed herein comprises a knitted fabric K knitted with piezoelectric yarn that contains a piezoelectric material and generates a surface potential in response to an external force, and woven fabrics W arranged on both sides of the knitted fabric, the knitted fabric being 50% or less of the woven fabrics arranged on both sides. [Selected Figure] Figure 1

Description

This disclosure relates to fabrics and textile products.

Patent Document 1 discloses a cylindrical structure that includes a first cloth and a second cloth made of knitted fabric having piezoelectric yarn that generates an electric potential in response to external energy, and a joint portion made of woven fabric that connects the first cloth and the second cloth.

International Publication No. 2021/106841

According to Patent Document 1, the expansion and contraction of the first and second knitted fabrics applies external energy to the piezoelectric yarn, generating an electric field that exerts an antibacterial effect.

In addition, the joint section made of woven fabric is less elastic than the first and second cloths made of knitted fabric, so when the cylindrical structure receives a deforming force from the outside, it distorts more than if the first and second cloths were made of knitted fabric alone. Therefore, it is known that an electric field can be generated even when a small force is applied (see paragraph [0043] of Patent Document 1).

However, Patent Document 1 does not disclose the appropriate ratio of the "first and second fabrics made of knitted fabric" to the "joint portion made of woven fabric," leaving room for improvement in order to generate a surface potential more appropriately.

In addition, it was difficult to directly apply the technology disclosed in Patent Document 1, which relates to "a fabric whose main component is stretchy (i.e., knitted fabric)," to textile products such as blousons, whose fabric has a low overall stretch rate, because the overall stretch rate of the fabric is conflicting between woven fabric and knitted fabric.

Therefore, the present disclosure aims to provide a fabric and textile product that can generate a surface potential more appropriately for fabrics with a relatively low elongation rate.

The fabric of the present disclosure includes a knitted fabric knitted with piezoelectric yarn that contains a piezoelectric material and generates a surface potential in response to an external force, and a woven fabric disposed on both sides of the knitted fabric,
The knitted fabric is 50% or less than the woven fabric disposed on both sides of the fabric.

The textile products disclosed herein use the above fabrics.

According to the present disclosure, for a fabric in which the proportion of woven fabric is higher than that of knitted fabric, by setting the proportion of knitted fabric to 50% or less of the woven fabric arranged on both sides, a surface potential can be generated more effectively. Note that the effects described in this specification are merely examples and are not limiting, and additional effects may also be present.

FIG. 1(A) is a schematic diagram of a fabric of the present disclosure, and FIG. 1(B) is a schematic diagram of a modified example of the fabric of the present disclosure. FIG. 2(A) is a schematic diagram of another modified example of the fabric of the present disclosure, and FIG. 2(B) is a schematic diagram of another modified example of the fabric of the present disclosure. Figure 3 (A) is a diagram showing the structure of a piezoelectric yarn (S yarn), Figure 3 (B) is a cross-sectional view along line A-A in Figure 3 (A), and Figure 3 (C) is a cross-sectional view along line B-B in Figure 3 (A). 4A and 4B are diagrams showing the relationship between the uniaxial stretching direction of polylactic acid, the direction of electric potential, and the deformation of the electric potential forming filament. Figure 5 (A) is a diagram showing the structure of a piezoelectric yarn (Z yarn), Figure 5 (B) is a cross-sectional view along line A-A in Figure 5 (A), and Figure 5 (C) is a cross-sectional view along line B-B in Figure 5 (A). FIG. 6 is a schematic cross-sectional view of a yarn having a dielectric around a potential-forming filament. FIG. 7(A) is a schematic diagram of a blouson illustrating an example of the textile product of the present disclosure, and FIG. 7(B) is a schematic diagram of a modified example of the blouson illustrating an example of the textile product of the present disclosure. FIG. 8 is a schematic diagram of another modified example of a blouson illustrating an example of the textile product of the present disclosure. FIG. 9 is a schematic diagram of pants showing an example of the textile product of the present disclosure. FIG. 10 is a schematic diagram of a modified example of pants showing an example of the textile product of the present disclosure.

The fabrics and textile products of the present disclosure will be described below. Although the description will be given with reference to the drawings as necessary, the contents shown in the drawings are merely schematic and illustrative for the understanding of the present disclosure, and the appearance and dimensional ratios may differ from the actual products. In addition, the various numerical ranges mentioned in this specification are intended to include the lower and/or upper limit values themselves unless otherwise specified. In other words, for example, a numerical range such as 1 to 10 can be interpreted as including the lower limit value of "1" and also the upper limit value of "10". In addition, various numerical values may be accompanied by "about" or "about", and the terms "about" and "about" mean that the range may include a variation of a few percent, for example, ±10%, ±5%, ±3%, ±2%, or ±1%.

-Description of the Fabric of the Present Disclosure-
The fabric F of the present disclosure comprises a knitted fabric K woven with piezoelectric yarn that contains a piezoelectric material and generates a surface potential in response to an external force, and a woven fabric W arranged on both sides of the knitted fabric K.

<Knitted fabric>
The knitted fabric K of the present disclosure may have a structure having a structure formed by connecting a plurality of loops to each other, i.e., a knit structure, as shown in, for example, FIG. 1(A) and FIG. 1(B). For example, a knitted fabric can be knitted by making a loop (e.g., a loop-shaped portion) of a piezoelectric yarn and continuously hooking the next loop to the loop to form a surface or structure. More specifically, the knitted fabric K may have a structure that can be formed by a knitting method such as weft knitting, warp knitting, circular knitting, tubular knitting, or sock knitting. Such knitted fabric K also includes tricot and raschel. In addition, sewn products such as cut and sewn and knit sewn are also included in the knitted fabric K of the present disclosure. Furthermore, non-sewn products such as whole garments are also included in the knitted fabric K of the present disclosure (WHOLEGARMENT (registered trademark)).

Examples of weaves that may be included in the knitted fabric K of the present disclosure include, but are not limited to, jersey (also called flat knit or stockinette knit), bare jersey, plating jersey, smooth (also called interlock), pique (front pique, back pique), knit miss (also called float), honeycomb, thermal (also called waffle), and milling. The weaves on the front and back of the knitted fabric K may be different. The weave may also include "tucks." In other words, tuck knitting may also be used. The weave may include "miss." The knitted fabric K may be reverse pile or reverse brushed. Depending on the weave, the feel, breathability, stretchability, and the like of the fabric can be changed.

In this disclosure, a structure that includes the minimum repeating units of "knits," and optionally "tucks" and/or "misses," is referred to as a "complete structure."

Such a structure may be formed using a knitting machine or by hand knitting. If a knitting machine is used, there is no particular restriction on the type, and any conventionally known knitting machine may be used without particular restriction.

In the fabric F of the present disclosure, the knitted fabric K is 50% or less of the woven fabrics arranged on both sides. In this specification, "ratio" refers to a ratio based on area ratio, but it may also be a ratio based on width dimension. The basis for this numerical range will be described in detail in the [Example] below. By setting such a numerical range, a surface potential can be more appropriately generated for fabric F, which has a relatively low elongation rate.

In addition, as long as the knitted fabric K is 50% or less of the woven fabrics arranged on both sides, the shape of the knitted fabric K is not limited to the rectangular shape shown in Figures 1(A) and 1(B). For example, the shape of the knitted fabric K may be a circle, an ellipse, or a polygon.

Furthermore, as for the shape of the knitted fabric K, when the direction in which the knitted fabric K is adjacent to the woven fabric W is the adjacent direction X and the direction in which the knitted fabric K intersects with the adjacent direction X is the intersecting direction Y, as shown in FIG. 2(A), the length dimension L1 of the outer side of the knitted fabric on one side in the intersecting direction Y may be different from the length dimension L2 of the outer side of the knitted fabric on the other side. In this case, the ratio of the knitted fabric K may be a ratio based on the area ratio, but it is also possible to measure the length dimensions of the knitted fabric K and the woven fabric W when a straight line is drawn parallel to the adjacent direction X, and to make the ratio of the knitted fabric K fall within the above-mentioned numerical range no matter how the straight line is drawn. In addition, as shown in FIG. 2(B), the area ratio of the knitted fabric in the center of the intersecting direction Y may be large, and the area ratio of the knitted fabric outside the center may be small. Even with such a shape, the knitted fabric K is 50% or less of the woven fabric W arranged on both sides, so that the surface potential can be appropriately generated.

Furthermore, as a preferred embodiment of the fabric of the present disclosure, it is preferable to bring the longer side of the length dimension of the knitted fabric K shown in FIG. 2(A) close to the wearer's joints. With this configuration, when the knitted fabric K expands and contracts in accordance with the movement of the wearer's joints, an external force (e.g., tensile stress and/or tensile strain) is applied to many areas of the knitted fabric K that constitutes the knitted fabric K, so that a surface potential can be generated more appropriately. Similarly to the above, the knitted fabric K shown in FIG. 2(B) may also be arranged so that the wearer's joints are close to the area where the area ratio of the knitted fabric K in the center of the cross direction Y is large. Even with this configuration, an external force is applied to many areas of the knitted fabric K, so that a surface potential can be generated more appropriately in the knitted fabric K.

Piezoelectric Yarn Next, the piezoelectric yarn 1 constituting the knitted fabric K in the fabric F of the present disclosure will be described with reference to Figures 3 to 6. The piezoelectric yarn 1 comprises "potential-forming filaments 10" (or fibers capable of forming an electric field by a surface charge). There is no particular limit to the number of potential-forming filaments 10, and the yarn of the present disclosure may comprise, for example, 2 or more, 2 to 500 filaments, preferably 10 to 350 filaments, and more preferably about 20 to 200 filaments.

In this disclosure, the term "potential-generating filament" basically means, as described above, "a fiber (filament) that can generate electric charge by external energy (e.g., tension and/or stress, etc.) to form an electric potential (specifically, a surface potential) and/or an electric field" (hereinafter, it may be referred to as "potential-generating fiber", "potential-generating filament", "electric field-generating fiber", "charge-generating fiber" or "charge-generating filament"). For example, the charge-generating fiber described in Japanese Patent No. 6428979 may be used as the potential-generating filament. The term "potential-generating filament" can be used substantially synonymously with "electric field-generating filament".

Examples of "external energy" include external forces (hereinafter sometimes referred to as "external forces"), specifically forces that cause deformation or distortion in the piezoelectric yarn 1 or potential-forming filament 10 and/or forces acting in the axial direction of the piezoelectric yarn 1 or potential-forming filament 10, and more specifically external forces such as tension (e.g., tensile force in the axial direction of the piezoelectric yarn 1 or potential-forming filament 10) and/or stress or strain force (tensile stress or tensile strain on the piezoelectric yarn 1 or potential-forming filament 10) and/or forces acting in the transverse direction of the piezoelectric yarn 1 or potential-forming filament 10.

In the piezoelectric yarn 1, the surface potential generated by the application of an external force may be, for example, greater than 0.5 V, preferably 1.0 V or greater (either positive or negative potentials can be generated). When a surface potential greater than 0.5 V is generated, the growth of bacteria can be suppressed in the fabric F of the present disclosure. There are no particular limitations on the method for measuring the surface potential, and it can be measured, for example, using a scanning probe microscope. In addition, the surface potential may have a direct bactericidal or virucidal effect, or may have an effect of repelling bacteria and viruses by generating a potential opposite to the potential possessed by bacteria, fungi, and other fungi and viruses.

There are no particular limitations on the dimensions (length, thickness (diameter), etc.) or shape (cross-sectional shape, etc.) of the potential-forming filament 10. A piezoelectric yarn 1 having such a potential-forming filament 10 may include multiple potential-forming filaments 10 of different thicknesses. Thus, the diameter of the piezoelectric yarn 1 may or may not be constant in the length direction.

The potential-forming filament 10 may be a long fiber or a short fiber. The potential-forming filament 10 may have a length (dimension) of, for example, 0.01 mm or more. The length may be selected appropriately depending on the desired application.

There is no particular restriction on the thickness (diameter) of the potential-forming filament 10, and it may or may not be the same (constant) along the length of the potential-forming filament 10. The potential-forming filament 10 may have a thickness of, for example, 0.001 μm (1 nm) to 1 mm. The thickness may be selected appropriately depending on the desired application.

Furthermore, it is preferable that the fiber strength of the piezoelectric yarn 1 is 1 to 10 cN/dtex. This allows the piezoelectric yarn 1 to withstand large deformations caused by generating a high electric potential without breaking. A fiber strength of 1 to 7 cN/dtex is more preferable, and 1 to 5 cN/dtex is most preferable. For the same reason, it is preferable that the elongation rate of the piezoelectric yarn 1 is greater than 5% and equal to or less than 50%.

There are no particular limitations on the shape of the potential forming filament 10, particularly its cross-sectional shape, but it may have a circular, elliptical, rectangular, or irregular cross-section, for example. It is preferable for it to have a circular cross-sectional shape.

The potential-forming filament 10 is preferably made of a material (hereinafter sometimes referred to as a "piezoelectric material" or "piezoelectric body") that has, for example, a piezoelectric effect (polarization phenomenon caused by an external force) or piezoelectricity (the property of generating a voltage when mechanical strain is applied, or conversely, generating mechanical strain when a voltage is applied). In particular, it is preferable to use a fiber (hereinafter sometimes referred to as a "piezoelectric fiber") that contains a piezoelectric material. Since piezoelectric fibers can generate an electric field by piezoelectricity, no power source is required and there is no risk of electric shock. The life of the piezoelectric material contained in the piezoelectric fiber lasts longer than the antibacterial effect of, for example, a drug. In addition, such piezoelectric fibers are less likely to cause allergic reactions.

The "piezoelectric material" can be any material that has a piezoelectric effect or piezoelectricity, and can be an inorganic material such as piezoelectric ceramics, or an organic material such as a polymer.

The "piezoelectric material" (or "piezoelectric fiber") preferably comprises a "piezoelectric polymer." Examples of the "piezoelectric polymer" include a "piezoelectric polymer with pyroelectric properties" and a "piezoelectric polymer without pyroelectric properties."

"Piezoelectric polymer with pyroelectricity" generally means a piezoelectric material made of a polymer material that has pyroelectricity and can generate an electric charge (or electric potential) on its surface simply by applying a temperature change. An example of such a piezoelectric polymer is polyvinylidene fluoride (PVDF). In particular, those that can generate an electric charge (or electric potential) on their surface by the thermal energy of the human body are preferable.

"Piezoelectric polymers without pyroelectric properties" generally refers to piezoelectric polymers made of polymer materials, excluding the above-mentioned "piezoelectric polymers with pyroelectric properties." Examples of such piezoelectric polymers include polylactic acid (PLA). Known examples of polylactic acid include poly-L-lactic acid (PLLA) in which L-monomers are polymerized, and poly-D-lactic acid (PDLA) in which D-monomers are polymerized.

The piezoelectric yarn 1 may be configured as a potential-generating filament 10 (or charge-generating fiber) in which a conductor is used as the core yarn, the conductor is wrapped (covered) with an insulator, and a voltage is applied to the conductor to generate an electric charge.

The piezoelectric yarn 1 may be a yarn (pulled yarn or untwisted yarn) in which multiple electric potential-generating filaments 10 are simply pulled together, a twisted yarn (twisted yarn or twisted yarn), a crimped yarn (crimped yarn or false twisted yarn), or a spun yarn (spun yarn). There are no particular limitations on the method of twisting, crimping, or spinning the yarn, and any conventionally known method may be used.

For example, as shown in FIG. 3(A), the piezoelectric yarn 1s can be constructed by twisting together multiple potential-forming filaments 10. In the embodiment shown in FIG. 3(A), the piezoelectric yarn 1s is a left-handed twisted yarn (hereinafter referred to as "S yarn") in which the potential-forming filaments 10 are twisted to the left, but it may also be a right-handed twisted yarn (hereinafter referred to as "Z yarn") in which the potential-forming filaments 10 are twisted to the right (see, for example, piezoelectric yarn 1z in FIG. 5(A)). Thus, when the piezoelectric yarn 1 is a twisted yarn, it may be either an "S yarn" or a "Z yarn".

In the piezoelectric yarn 1, the spacing between the potential-forming filaments 10 is approximately 0 μm to approximately 10 μm, typically around 5 μm. When the spacing between the potential-forming filaments 10 is 0 μm, this means that the electric field-forming filaments are in contact with each other.

To describe the piezoelectric yarn 1 in detail, an example of the piezoelectric yarn 1 will be described in more detail below with reference to Figures 3 to 5, using as an example an embodiment in which the potential-generating filament 10 contains a piezoelectric material, and the piezoelectric material is "polylactic acid."

Polylactic acid (PLA), which can be used as a piezoelectric material, is a chiral polymer with a helical structure in its main chain. When polylactic acid is uniaxially stretched and the molecules are oriented, it can exhibit piezoelectricity. Furthermore, if the degree of crystallinity is increased by heat treatment, the piezoelectric constant increases. Increasing the degree of crystallinity in this way can improve the value of the surface potential.

The optical purity (enantiomeric excess (ee)) of polylactic acid (PLA) can be calculated by the following formula.
Optical purity (%)={|amount of L-form−amount of D-form|/(amount of L-form+amount of D-form)}×100
For example, in both the D- and L-isomers, the optical purity is 90% by weight or more, preferably 95% by weight or more, more preferably 98% by weight or more and 100% by weight or less, even more preferably 99.0% by weight or more and 100% by weight or less, and particularly preferably 99.0% by weight or more and 99.8% by weight or less. The amounts of the L- and D-isomers of polylactic acid (PLA) can be values obtained by, for example, a method using high performance liquid chromatography (HPLC).

As shown in FIG. 3(A), the potential-generating filament (or piezoelectric fiber) 10, which is made of uniaxially stretched polylactic acid, has tensor components of d14 and d25 as piezoelectric strain constants when the thickness direction is defined as the first axis, the stretching direction 900 as the third axis, and the direction perpendicular to both the first axis and the third axis as the second axis.

Therefore, polylactic acid can generate electric charge (or potential) most efficiently when it is distorted at 45 degrees to the uniaxially stretched direction.

The number average molecular weight (Mn) of polylactic acid is, for example, 6.2×10 ⁴ , and the weight average molecular weight (Mw) is, for example, 1.5×10 ^5. However, the molecular weights are not limited to these values.

Figures 4(A) and 4(B) show the relationship between the uniaxial stretching direction of polylactic acid, the electric field direction, and the deformation of a fiber including a potential-forming filament 10 and/or a piezoelectric yarn 1.

As shown in FIG. 4(A), when the potential-forming filament 10 shrinks in the direction of the first diagonal 910A and expands in the direction of the second diagonal 910B perpendicular to the first diagonal 910A, it can generate an electric field in the direction from the back side to the front side of the paper. That is, the potential-forming filament 10 can generate a negative charge on the front side of the paper. As shown in FIG. 4(B), when the potential-forming filament 10 expands in the direction of the first diagonal 910A and contracts in the direction of the second diagonal 910B, it can also generate a charge (or potential), but the polarity is reversed, and an electric field can be generated in the direction from the front side of the paper to the back side. That is, the potential-forming filament 10 can generate a positive charge on the front side of the paper.

Since piezoelectricity can be generated in polylactic acid by molecular orientation processing through stretching, there is no need to perform poling processing as with other piezoelectric polymers such as polyvinylidene fluoride (PVDF) or piezoelectric ceramics. The piezoelectric constant of uniaxially stretched polylactic acid is approximately 5 to 30 pC/N, which is a very high piezoelectric constant among polymers. Furthermore, the piezoelectric constant of polylactic acid does not fluctuate over time and is extremely stable.

The potential-forming filament 10 is preferably a fiber having a circular cross section. The potential-forming filament 10 can be manufactured by, for example, a method of extruding a piezoelectric polymer to form a fiber, a method of melt spinning a piezoelectric polymer to form a fiber (including, for example, a spinning and drawing method in which the spinning process and the drawing process are performed separately, a straight drawing method in which the spinning process and the drawing process are combined, a POY-DTY method in which a false twisting process can also be performed simultaneously, or an ultra-high-speed spinning method that aims to increase speed), a method of dry or wet spinning a piezoelectric polymer (including, for example, a phase separation method or a dry and wet spinning method in which a raw polymer is dissolved in a solvent and extruded from a nozzle to form a fiber, a gel spinning method in which a gel is uniformly formed while still containing the solvent, or a liquid crystal spinning method in which a liquid crystal solution or melt is used to form a fiber), or a method of electrostatically spinning a piezoelectric polymer to form a fiber. The cross-sectional shape of the potential-forming filament 10 is not limited to a circular shape.

For example, the piezoelectric yarn 1s shown in FIG. 3 may be a yarn (multifilament yarn) (S yarn) made by twisting together multiple potential-forming filaments 10 containing such polylactic acid (there is no particular restriction on the twisting method). The extension direction 900 of each potential-forming filament 10 coincides with the axial direction of each potential-forming filament 10. Therefore, the extension direction 900 of the potential-forming filament 10 is tilted to the left with respect to the axial direction of the piezoelectric yarn 1s. The angle depends on the number of twists.

When an "external force", such as tension (preferably axial tension) or stress (preferably axial tensile stress) is applied to such an S-thread piezoelectric thread 1s, a negative (-) charge (or potential) is generated on the surface of the piezoelectric thread 1, and a positive (+) charge (or potential) can be generated inside it.

The piezoelectric yarn 1 can create an electric field due to the potential difference that can be generated by this charge. This electric field can also leak into the nearby space and form a combined electric field with other parts. Furthermore, the potential generated in the piezoelectric yarn 1 can also generate an electric field between the piezoelectric yarn 1 and an object when it is close to a predetermined potential, such as a human body, that has a predetermined potential (including ground potential).

Next, referring to FIG. 5, since the piezoelectric yarn 1z is a Z-yarn, the extension direction 900 of the potential-forming filament (or piezoelectric fiber) 10 is tilted to the right with respect to the axial direction of the piezoelectric yarn 1z. Note that this angle depends on the number of times the yarn is twisted.

When an "external force", such as tension (preferably axial tension) or stress (preferably axial tensile stress) is applied to such a Z-thread, piezoelectric thread 1z, a positive (+) charge (or potential) is generated on the surface of piezoelectric thread 1z, and a negative (-) charge (or potential) can be generated inside it.

The piezoelectric yarn 1z can also form an electric field due to the potential difference that can be generated by this charge. This electric field can also leak into the nearby space and form a combined electric field with other parts. Furthermore, the potential generated in the piezoelectric yarn 1z can also generate an electric field between the piezoelectric yarn 1z and an object when it is close to a predetermined potential, such as a human body, that has a predetermined potential (including ground potential).

Furthermore, when piezoelectric yarn 1s, which is an S-thread, and piezoelectric yarn 1z, which is a Z-thread, are brought close to each other, an electric field can be generated between piezoelectric yarn 1s and piezoelectric yarn 1z.

The polarities of the electric charges (or potentials) generated in the piezoelectric yarns 1s and 1z are different from each other. The potential difference at each point can be defined by an electric field coupling circuit that can be formed by the intricate entanglement of the fibers, or a circuit that can be formed by a current path that can accidentally form in the yarn due to moisture, etc.

A deeper understanding of piezoelectric yarn 1s and piezoelectric yarn 1z can be obtained by reading Patent No. 6428979. Patent No. 6428979 is also incorporated by reference into this specification.

In the piezoelectric yarn 1, the potential-forming filament 10 is preferably made of polylactic acid (PLA). When the potential-forming filament 10 contains a piezoelectric material such as polylactic acid, the surface potential can be more appropriately controlled. In addition, since polylactic acid is hydrophobic, it can provide a smooth feel on the skin, which can also provide comfort to the knitted structure. In addition, since polylactic acid is known as a biodegradable plastic, it can eventually decompose into _CO2 and water, thereby reducing the burden on the environment.

The degree of crystallinity of "polylactic acid" is, for example, 20% or more, preferably 30% or more, more preferably 40% or more, even more preferably 50% or more, and particularly preferably 55% or more. The degree of crystallinity can be determined by a measurement method such as a differential scanning calorimetry (DSC), X-ray diffraction (XRD), or wide angle X-ray diffraction (WAXD). Within such a range, the piezoelectricity derived from the polylactic acid crystals is high, and polarization due to the piezoelectricity of polylactic acid can be more effectively generated. In the present disclosure, it has been found that the measured value of the crystallinity measured using WAXD and the measured value of the crystallinity measured using DSC differ by about 1.5 times (DSC measured value/WAXD measured value ≒ 1.5).

The piezoelectric yarn 1 does not contain additives such as plasticizers or lubricants. It is generally known that if the piezoelectric yarn 1 contains additives, it tends to be difficult for a surface potential to be generated. Therefore, in order to properly generate a surface potential, it is preferable that the piezoelectric yarn 1 does not contain additives. In this disclosure, a "plasticizer" is a material that gives flexibility to the piezoelectric yarn 1, and a "lubricant" is a material that improves the slippage of the molecules of the piezoelectric yarn 1. Specifically, polyethylene glycol, castor oil-based fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyethylene glycol fatty acid ester, stearic acid amide, glycerin fatty acid ester, etc. are intended. These materials are not contained in the piezoelectric yarn 1 of the present disclosure.

The piezoelectric yarn 1 may contain a hydrolysis inhibitor. In particular, a hydrolysis inhibitor for polylactic acid (PLA) may be contained. As an example of a hydrolysis inhibitor, a carbodiimide may be contained. More preferably, a cyclic carbodiimide may be contained. More specifically, the cyclic carbodiimide described in Japanese Patent No. 5475377 may be used. Such a cyclic carbodiimide can effectively seal the acidic groups of the polymer compound. In addition, a carboxyl group sealing agent may be used in combination with the cyclic carbodiimide compound to an extent that the acidic groups of the polymer can be effectively sealed. Examples of such a carboxyl group sealing agent include agents described in Japanese Patent Publication No. 2005-2174, such as epoxy compounds, oxazoline compounds and/or oxazine compounds.

The role of the hydrolysis inhibitor will be explained below. In conventionally known fibers or filaments containing PLA (fibers or filaments that do not generate a surface potential), acid is generated by hydrolysis of PLA, and the acid acts on bacteria, thereby exerting an antibacterial effect. Therefore, when hydrolysis occurs in PLA, the fibers or filaments deteriorate. However, the potential-forming fibers or potential-forming filaments of the present disclosure have an antibacterial mechanism different from conventional ones, and exert an antibacterial effect by generating a surface potential as described above, so there is no need to cause hydrolysis. Furthermore, since the potential-forming fibers or potential-forming filaments of the present disclosure contain a hydrolysis inhibitor, it is possible to prevent hydrolysis from occurring in the fibers or filaments and suppress deterioration of the fibers or filaments.

Piezoelectric yarn 1 should not be interpreted as being limited to the above-mentioned aspects, particularly yarn that may be made of polylactic acid. In addition, there are no particular limitations on the manufacturing method of piezoelectric yarn 1, and it is not limited to the above-mentioned manufacturing method.

Other aspects of piezoelectric yarn Furthermore, the piezoelectric yarn 1 may have a "dielectric" provided around the potential-forming filament 10. For example, as shown diagrammatically in the cross-sectional view of Fig. 6, a dielectric 100 can be provided around the potential-forming filament (or piezoelectric fiber) 10.

In this disclosure, "dielectric" refers to a material or substance that has "dielectricity" (the property of being electrically polarized positively and negatively (or dielectric polarization or electric polarization) by an electric field) and is capable of storing electric charges on its surface.

The dielectric 100 may be present in the longitudinal direction and circumferential direction of the potential-forming filament 10, and may completely or partially cover the electric field-forming filament. When the dielectric 100 partially covers the potential-forming filament 10, the potential-forming filament 10 itself may be exposed in the uncovered portion.

Therefore, the dielectric 100 may be provided over the entire area or part of the potential-forming filament 10 in the longitudinal direction. The dielectric 100 may be provided over the entire area or part of the potential-forming filament 10 in the circumferential direction. The dielectric 100 may be uniform or non-uniform in thickness.

The dielectric 100 may be present between multiple potential-forming filaments 10, and in this case, there may be a portion between the multiple potential-forming filaments 10 where the dielectric 100 is not present. Also, air bubbles or cavities may be present in the dielectric 100.

There are no particular limitations on the dielectric 100 as long as it contains a material or substance having dielectric properties. The dielectric 100 may be a dielectric material (e.g., an oil agent, an antistatic agent, etc.) that is known to be usable as a surface treatment agent (or fiber treatment agent) mainly in the textile industry.

In the piezoelectric yarn 1, the dielectric 100 preferably contains an oil. As the oil, an oil (yarn-making oil) used as a surface treatment agent (or fiber treatment agent) that can be used in the manufacture of the potential-forming filament 10 can be used (for example, an anionic, cationic or nonionic surfactant). In addition, an oil (for example, an anionic, cationic or nonionic surfactant) used as a surface treatment agent (or fiber treatment agent) that can be used in the process of fabric-making (for example, knitting, weaving, etc.) or an oil (for example, an anionic, cationic or nonionic surfactant) used as a surface treatment agent (or fiber treatment agent) that can be used in the finishing process can also be used. Here, the filament manufacturing process, the fabric-making process, the finishing process, etc. are given as representative examples, but the present invention is not limited to these processes. As the oil, it is preferable to use an oil used to reduce the friction of the potential-forming filament 10.

Examples of oils include the Delion series manufactured by Takemoto Oil Co., Ltd., the Marposol series and Marposize series manufactured by Matsumoto Yushi Seiyaku Co., Ltd., and the Paratex series manufactured by Marubishi Yuka Kogyo Co., Ltd.

The oil may be present along the entire surface of the potential-forming filament 10, or at least partially along the entire surface of the potential-forming filament 10. After the potential-forming filament 10 is processed into the piezoelectric yarn 1, at least some or all of the oil may fall off from the potential-forming filament 10 by washing.

The dielectric 100 used to reduce friction of the potential-forming filament 10 may also be a surfactant such as a detergent or fabric softener used in laundry.

Examples of detergents include the Attack (registered trademark) series manufactured by Kao Corporation, the Top (registered trademark) series manufactured by Lion Corporation, and the Ariel (registered trademark) series manufactured by Procter & Gamble Japan Co., Ltd.

Examples of fabric softeners include the Humming (registered trademark) series manufactured by Kao Corporation, the Soflan (registered trademark) series manufactured by Lion Corporation, and the Lenor (registered trademark) series manufactured by Procter & Gamble Japan Co., Ltd.

The dielectric 100 may be conductive (the property of conducting electricity), in which case it is preferable that the dielectric 100 contains an antistatic agent. As the antistatic agent, an antistatic agent used as a surface treatment agent (or fiber treatment agent) that can be used in the manufacture of the potential-forming filament 10 can be used. As the antistatic agent, it is preferable to use an antistatic agent that is used in particular to reduce the fraying of the potential-forming filament 10.

Examples of antistatic agents include the Kapron series manufactured by Nisshin Chemical Laboratory Co., Ltd., and the Nicepol series and Dateron series manufactured by Nicca Chemical Co., Ltd.

The antistatic agent may be present along the entire length of the potential-forming filament 10, or may be present at least partially along the entire length of the potential-forming filament 10. After the potential-forming filament 10 is processed into the piezoelectric yarn 1, at least some or all of the antistatic agent may fall off from the potential-forming filament 10 by washing.

In addition, the above-mentioned surface treatment agents (or fiber treatment agents) such as oils and antistatic agents, detergents, fabric softeners, etc. may not be present around the potential-forming filament 10. In other words, the potential-forming filament 10 or the piezoelectric yarn 1 may not contain the above-mentioned surface treatment agents (or fiber treatment agents) such as oils and antistatic agents, detergents, fabric softeners, etc. In that case, the air (or air layer) present between the potential-forming filaments 10 may function as a dielectric. Therefore, in this case, the dielectric comprises air.

For example, a piezoelectric yarn 1 that does not contain the above-mentioned surface treatment agent (or fiber treatment agent), detergent, fabric softener, etc., may be used by treating a yarn that has the above-mentioned oil agent or antistatic agent, detergent, fabric softener, etc. attached around the potential-forming filament 10 by washing or immersion in a solvent. In this case, the solid potential-forming filament 10 will be exposed. Alternatively, in the present disclosure, a piezoelectric yarn 1 that includes only the solid potential-forming filament 10 may be used.

In addition, in the present disclosure, a yarn may be used in which the above-mentioned surface treatment agents (or fiber treatment agents) such as oils and antistatic agents, detergents, fabric softeners, etc. have been partially removed by a process such as washing or immersion in a solvent, thereby partially exposing the pure potential-forming filament 10.

The thickness of the dielectric 100 (or the spacing between the potential-forming filaments 10) is about 0 μm to about 10 μm, preferably about 0.5 μm to about 10 μm, more preferably about 2.0 μm to about 10 μm, and typically about 5 μm.

<Woven fabric>
As shown in Figs. 1(A) and (B), the woven fabric W may be a fabric formed by arranging warp threads in parallel and interlacing weft threads at right angles thereto according to a certain rule. The warp threads and weft threads used in the woven fabric W may be general natural fibers or chemical fibers. The woven fabric W may also use the above-mentioned "piezoelectric yarn containing electric field-forming filaments." When the woven fabric W uses piezoelectric yarn containing electric field-forming filaments, an electric field may be formed in the woven fabric W by applying external energy to the piezoelectric yarn constituting the woven fabric W. From the viewpoint of making the knitted fabric K more stretchable, it is preferable to use yarn for the woven fabric W that is less stretchable than the yarn used for the knitted fabric K.

The weave of the woven fabric W is not particularly limited. For example, examples of the weave include three basic weaves such as plain weave, twill weave, and satin weave, alternating weaves, single double weaves such as warp double weave and weft double weave, full double weave, and warp velvet. The number of layers may be a single layer or two or more layers. In particular, it is preferable to make the fabric a multi-layered fabric with two or more layers, and to increase water absorption by capillary action by making the total fineness or single fiber fineness of the fibers constituting each layer different, or by making the density different.

The woven fabric W has a larger ratio than the knitted fabric K sandwiched between the woven fabrics W. Generally, woven fabric W is less stretchable than knitted fabric K, so the elongation rate of a cloth with a large ratio of woven fabric W is low. As an example, the elongation rate of the entire cloth F may be 4% or less. When such a cloth with a low elongation rate is stretched from both sides, external energy based on the elongation can be effectively applied to the knitted fabric K. Specifically, knitted fabrics with a large area ratio are less likely to elongate, and knitted fabrics with a small area ratio elongate. Therefore, external energy is applied to the piezoelectric yarn that constitutes the knitted fabric K, generating a surface potential on the piezoelectric yarn, and the surface potential can exert an antibacterial effect.

As shown in FIG. 1A, the woven fabric W may be arranged perpendicular to the knitting direction of the knitted fabric K. Here, the "knitting direction" in this specification refers to the direction in which the yarn constituting the knitted fabric K is supplied, and in FIG. 1A, the knitting direction coincides with the cross direction Y. By arranging the woven fabric W relative to the knitted fabric K in this way, it is possible to appropriately impart external energy to the piezoelectric yarn constituting the knitted fabric K. Specifically, the knitted fabric K is easily stretched in the knitting direction due to the loosening of the knitting loops, but the knitted fabric K is less likely to stretch in the cross direction Y compared to the knitting direction. Therefore, more energy can be imparted to the piezoelectric yarn constituting the knitted fabric K by the amount that the knitted fabric K is less likely to stretch. Therefore, a surface potential can be generated in the knitted fabric K more efficiently.

As shown in FIG. 1B, the woven fabric W may be arranged parallel to the knitting direction (adjacent direction X) of the knitted fabric K. Even in this case, a surface potential can be generated on the knitted fabric K.

-Description of the textile product of the present disclosure-
Next, a specific embodiment of the textile product C of the present disclosure will be described. The textile product C of the present disclosure uses the fabric F described above. Examples of the textile product C of the present disclosure include a blouson (see Figs. 7 and 8) or pants (see Figs. 9 and 10). Specific textile products C will be described below.

1. Blouson When the textile product C is a blouson, the piezoelectric yarn constituting the knitted fabric K can be expanded or contracted by the movement of the upper body. Therefore, the term "blouson" as used in this specification refers to an article of clothing that can be worn on the upper body. In other words, the term can be applied to other tops, jackets, etc. other than "blouson."

As an example of a position where the knitted fabric K is arranged in the textile product C, it may be the armpit near the shoulder joint, as shown in FIG. 7(A). More preferably, the knitted fabric K may extend from the armpit of the wearer to the ilium. In the case of the textile product C shown in FIG. 7(A), the ratio of the knitted fabric K is calculated based on the width D1 of the knitted fabric K and the width D2 of the woven fabric W, but it may also be calculated based on the area of the knitted fabric K and the area of the woven fabric W.

Also, as shown in FIG. 7(B), the length dimension L3 of the knitted fabric K on the side of the armpit may be longer than the length dimension L4 of the knitted fabric K on the side of the iliac bone. In the embodiment shown in FIG. 7(B), since the area of the knitted fabric K on the side of the armpit is wide, energy can be efficiently applied to the piezoelectric yarn constituting the knitted fabric K in a more appropriate manner in accordance with the movement of the wearer's shoulder joint. Therefore, antibacterial properties can be appropriately imparted to the armpit area where sweating and bacteria are likely to grow. The ratio of the knitted fabric K is calculated based on the width D1 of the knitted fabric K and the width D2 of the woven fabric W, but may also be calculated based on the area of the knitted fabric K and the area of the woven fabric W. In the case of the textile product C shown in FIG. 7(B), the ratio of the knitted fabric K may be measured by measuring the length dimension of the knitted fabric K and the length dimension of the woven fabric W when a straight line is drawn parallel to the adjacent direction, and the ratio of the knitted fabric K may be within the above-mentioned numerical range of 50% or less no matter how the straight line is drawn. It is also possible to calculate the area ratio of the knitted fabric K and the area ratio of the woven fabric W, and then calculate the ratio of the knitted fabric K from the area ratio.

The position where the knitted fabric K is placed is not limited to the vicinity of the shoulder joint, but may be the vicinity of the elbow joint as shown in FIG. 8. In the case of the textile product C shown in FIG. 8, the ratio of the knitted fabric K is calculated based on the length D3 of the knitted fabric and the length D4 of the woven fabric W, but may also be calculated based on the area of the knitted fabric K and the area of the woven fabric W. Also, the area ratio of the knitted fabric K and the area ratio of the woven fabric W may be calculated, and the ratio of the knitted fabric K may be calculated from the area ratio.

2. Pants When the textile product C is pants, the piezoelectric yarn 1 constituting the knitted fabric K can be stretched and contracted by the movement of the lower body. Therefore, the term "pants" in this specification refers to an article that can be worn on the lower body.

As an example of the position where the knitted fabric K is arranged in the textile product C, it may be near the knee joint as shown in FIG. 9. In the case of the textile product C shown in FIG. 9, the ratio of the knitted fabric K is calculated based on the length D5 of the knitted fabric K and the length D6 of the woven fabric W, but it may also be calculated based on the area of the knitted fabric K and the area of the woven fabric W. According to this embodiment, energy can be efficiently applied to the piezoelectric yarn 1 constituting the knitted fabric K by the movement of the knee joint of the wearer. Note that the position where the knitted fabric K is arranged is not limited to the vicinity of the knee joint, and the knitted fabric K may extend from the ilium to the ankle as shown in FIG. 10. In the case of the textile product C shown in FIG. 10, the ratio of the knitted fabric K is calculated based on the width D7 of the knitted fabric K and the width D8 of the woven fabric W, but it may also be calculated based on the area of the knitted fabric K and the area of the woven fabric W.

Examples 1 to 5 and Comparative Example 1 of textile products using the fabric of the present disclosure will be described. The knitted fabric of the textile products of Examples 1 to 5 and Comparative Example 1 was a circular knit containing PLA (total fineness 84 decitex, number of filaments 72) and nylon (total fineness 78 decitex, number of filaments 48) in a ratio of 48:52, with a basis weight of 180 g/ ^m2 . The woven fabric of the textile products of Examples 1 and 2 was a plain weave made of 100% polyethylene terephthalate with a basis weight of 65 g/ ^m2 , and the woven fabric of the textile products of Examples 3 to 5 and Comparative Example 1 was a plain weave containing cotton and polyethylene terephthalate in a ratio of 65:35, with a basis weight of 250 g/ ^m2 . Here, the configurations of the knitted fabric and woven fabric are not limited to the above configurations, and may be the configurations described in <Knitted Fabric> and <Woven Fabric> in "Description of the Fabric of the Present Disclosure". In other words, the woven fabric may contain "piezoelectric yarn containing electric field forming filaments".

--Example 1--
A blouson was manufactured that had a cloth with woven fabrics arranged on both sides of a knitted fabric, and the knitted fabric was 2.5% of the woven fabrics arranged on both sides. Specifically, as shown in Fig. 7(A), a blouson was manufactured in which the width D1 of the knitted fabric K was 2.5 cm, and the widths D2 of the woven fabrics located on both sides (front and back) of the knitted fabric K were each 50 cm (total 100 cm). The ratio of the knitted fabric K was calculated based on the widths D1 and D2.

--Example 2--
A blouson was manufactured that had a cloth with woven fabrics arranged on both sides of a knitted fabric, and the knitted fabric was 10% of the woven fabrics arranged on both sides. Specifically, as shown in Fig. 7(A), a blouson was manufactured in which the width D1 of the knitted fabric K was 10 cm, and the widths D2 of the woven fabrics located on both sides (front and back) of the knitted fabric K were each 50 cm (total 100 cm). The ratio of the knitted fabric K was calculated based on the widths D1 and D2.

--Example 3--
Pants were manufactured that had a fabric with woven fabric arranged on both sides of a knitted fabric, and the knitted fabric was 17% of the woven fabric arranged on both sides. Specifically, as shown in FIG. 10, pants were manufactured in which the width D7 of the knitted fabric K was 5 cm, and the widths D8 of the woven fabrics on both sides of the knitted fabric K were each 15 cm (30 cm in total). The ratio of the knitted fabric K was calculated based on the widths D7 and D8.

--Example 4--
A pair of pants was manufactured that had a fabric with woven fabrics arranged on both sides of a knitted fabric, and the knitted fabric was 25% of the woven fabrics arranged on both sides. Specifically, as shown in Fig. 9, the length D5 of the knitted fabric K was 20 cm, and the lengths D6 of the woven fabrics located on both sides of the knitted fabric K were 45 cm and 35 cm, respectively (80 cm in total). The ratio of the knitted fabric K was calculated based on the length D5 and the length D6.

--Example 5--
A pair of pants was manufactured that had a fabric with woven fabrics arranged on both sides of a knitted fabric, and the knitted fabric was 50% of the woven fabrics arranged on both sides. Specifically, as shown in Fig. 9, the length D5 of the knitted fabric K was 50 cm, and the lengths D6 of the woven fabrics located on both sides of the knitted fabric K were 30 cm and 20 cm, respectively (50 cm in total). The ratio of the knitted fabric K was calculated based on the length D5 and the length D6.

--Comparative Example 1--
A pair of pants was manufactured that had a fabric with woven fabrics arranged on both sides of a knitted fabric, and the knitted fabric was 75% of the woven fabrics arranged on both sides. Specifically, as shown in Fig. 9, the length D5 of the knitted fabric K was 45 cm, and the lengths D6 of the woven fabrics located on both sides of the knitted fabric K were 35 cm and 25 cm, respectively (total of 60 cm). The ratio of the knitted fabric K was calculated based on the length D5 and the length D6.

As another textile product, we attempted to manufacture a cloth with woven fabric on both sides of a knitted fabric, with the knitted fabric being 1.6% of the woven fabric on both sides. Specifically, as shown in FIG. 7(A), we attempted to manufacture a blouson in which the width D1 of the knitted fabric K was 1.0 cm, and the width D2 of the woven fabric on both sides (front and back) of the knitted fabric K was 50 cm (total 100 cm). However, because the width of the knitted fabric K was narrow, it was impossible to sew the knitted fabric and the woven fabric together. In other words, it was practically impossible to manufacture a blouson with a knitted fabric width of 1.0 cm or less. Based on the above observations, it is preferable that the lower limit of the knitted fabric is longer than 1.0 cm in width.

For the above Examples 1 to 5 and Comparative Example 1, an elongation rate evaluation, a surface potential evaluation, and an antibacterial evaluation were performed. The specific evaluation contents are described below.

(Elongation Rate Evaluation)
Regarding evaluation of the elongation rate of the entire fabric, after wearing the products of the examples and comparative examples, the deformation of the parts that stretch as clothing (e.g., armpits and crotch) was measured while walking, and the elongation rate was measured based on the measurements. The measuring equipment, measurement range, and measurement conditions are as follows.
Measuring equipment: ARAMIS Adjustable Base 12M
Measurement range: 1160 x 940 x ^940mm2
Measurement conditions: 7Hz, f4.0

Regarding evaluation of elongation rate of knitted fabric, the same method as for evaluation of elongation rate of the whole fabric was used to measure the knitted fabric portion, and the elongation rate was determined based on the measurement.

(Surface potential evaluation)
For the products of the examples and comparative examples, the surface potential of the fabric was measured using an electric force microscope (EFM) (Trek, Model 1100TN). The surface potential was evaluated using a potential measuring device (see Japanese Patent Application No. 2021-065673) equipped with a pulling mechanism capable of pulling the products of the examples and comparative examples placed on a conductive block as a ground electrode in at least one direction. That is, (a) the yarn is stretched a predetermined amount in a uniaxial direction as described in Patent Document 1 (International Publication No. WO 2020/241432). (b) The fiber is covered on a core material made of conductive fibers. (c) The core material is grounded. (d) The surface potential of the yarn is measured using an electric force microscope. A method different from the measurement method of the above was adopted.

(Antibacterial evaluation)
The details of the antibacterial test are as follows.
(1) The viable cell count is measured for the comparative example and example products in their initial state.
(2) The viable cell counts of the products of the Comparative Example and the Example are measured after leaving them to stand for 18 hours.
(3) For the comparative example and example products that had been left stationary for 18 hours, the products were stretched and contracted continuously for 18 hours to generate a surface potential, after which the viable cell count was measured.
In other words, the "antibacterial activity value" in the present disclosure refers to a value calculated as follows.
Antibacterial activity value = Viable bacteria count A - Viable bacteria count B
Viable cell count A: Viable cell count after standing for 18 hours Viable cell count B: Viable cell count after the product was stretched and contracted continuously for 18 hours to generate a surface potential The viable cell count was evaluated based on the method of JIS L1902, as described in Japanese Patent No. 6922546 and Japanese Patent No. 6292368. The viable cell count value indicates the logarithm of the Colony Forming Unit (logarithm of colonies per 1 g).

The results of the elongation rate evaluation, surface potential evaluation, and antibacterial evaluation are shown in the table below.

According to the results in Table 1, the textile products of Examples 1 to 5 had a surface potential greater than 0.5 V for the textile product of Comparative Example 1, since the textile products had 50% or less knitted fabric relative to the woven fabrics on both sides. In addition, the antibacterial activity value was greater than the antibacterial activity value of 1.1 for the textile product of Comparative Example 1, indicating good antibacterial properties.

On the other hand, the textile product of Comparative Example 1 had a knitted fabric that was outside the range of 50% or less compared to the woven fabrics on both sides, and the surface potential and antibacterial activity values were worse than those of the textile products of Examples 1 to 5.

Aspects of the fabrics and textile products of the present disclosure are as follows.
<1> A cloth comprising: a knitted fabric made of piezoelectric yarn that contains a piezoelectric material and generates a surface potential in response to an external force; and a woven fabric arranged on both sides of the knitted fabric, wherein the knitted fabric is 50% or less in area relative to the woven fabrics arranged on both sides.
<2> The fabric according to <1>, wherein the knitted fabric has a width of more than 1 cm. <3> The fabric according to <1> or <2>, wherein the arrangement direction of the woven fabric relative to the knitted fabric is parallel to the knitting direction of the knitted fabric.
<4> The cloth described in <1> or <2>, wherein the arrangement direction of the woven fabric relative to the knitted fabric is perpendicular to the knitting direction of the knitted fabric.
<5> The fabric according to any one of <1> to <4>, wherein the elongation rate of the knitted fabric is greater than 5%.
<6> The fabric according to any one of <1> to <5>, wherein the elongation rate of the entire fabric is 4% or less.
<7> A fabric described in any one of <1> to <6>, wherein the length dimension of an outer side of the knitted fabric on one side in a direction intersecting the arrangement direction is different from the length dimension of the outer side of the knitted fabric on the other side.
<8> The fabric described in <7>, wherein the length dimension of the outer edge of one side of the knitted fabric is longer than the length dimension of the outer edge of the other side, and the one side of the knitted fabric is close to the wearer's joints.
<9> The cloth described in any one of <1> to <8>, wherein the piezoelectric material contains polylactic acid.
<10> The fabric described in <9>, wherein the piezoelectric material has a crystallinity of 20% or more.
<11> The fabric according to <9> or <10>, wherein the piezoelectric material does not contain any additives.
<12> The fabric according to any one of <9> to <11>, wherein the piezoelectric material contains a hydrolysis inhibitor.
<13> The fabric according to any one of <1> to <12>, which is capable of generating a potential of more than 0.5 V.
<14> A textile product using the fabric according to any one of <1> to <13>.

The embodiments disclosed herein are illustrative in all respects and are not intended to be a basis for restrictive interpretation. Therefore, the technical scope of the present invention is not interpreted solely by the above-described embodiments, but is defined based on the claims. Furthermore, the technical scope of the present invention includes all modifications that are equivalent in meaning to and within the scope of the claims.

The present disclosure can be used, for example, in fabrics and textile products that can generate a surface potential more appropriately for fabrics with a relatively low elongation rate.

1, 1s, 1z Piezoelectric yarn 10 Potential-forming filament 100 Dielectric 900 Extension direction 910A First diagonal 910B Second diagonal F Cloth C Textile product K Knitted fabric W Woven fabric

Claims (14)

The piezoelectric sensor comprises a knitted fabric made of piezoelectric yarn that contains a piezoelectric material and generates a surface potential by an external force, and a woven fabric disposed on both sides of the knitted fabric,
The knitted fabric is 50% or less than the woven fabric disposed on both sides of the fabric. The fabric of claim 1, wherein the knitted fabric is greater than 1 cm in width. The fabric according to claim 1, wherein the direction in which the woven fabric is arranged relative to the knitted fabric is parallel to the knitting direction of the knitted fabric. The fabric according to claim 1, wherein the direction in which the woven fabric is arranged relative to the knitted fabric is perpendicular to the knitting direction of the knitted fabric. The fabric of claim 1, wherein the elongation of the knitted fabric is greater than 5%. The fabric according to claim 1, wherein the overall elongation of the fabric is 4% or less. The fabric according to claim 1, wherein the length dimension of the outer side of the knitted fabric on one side in a direction intersecting the arrangement direction is different from the length dimension of the outer side of the knitted fabric on the other side. The fabric according to claim 7, wherein the length dimension of the outer edge of the one side of the knitted fabric is longer than the length dimension of the outer edge of the other side, and the one side of the knitted fabric is adjacent to the joints of the wearer. The fabric according to claim 1, wherein the piezoelectric material contained in the piezoelectric yarn includes polylactic acid. The fabric according to claim 9, wherein the piezoelectric material has a crystallinity of 20% or more. The fabric of claim 9, wherein the piezoelectric material does not contain any additives. The fabric of claim 9, wherein the piezoelectric material contains a hydrolysis inhibitor. The fabric of claim 1, capable of generating a potential greater than 5 V. A textile product using the fabric according to any one of claims 1 to 13.

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