Knitted fabric structures, socks, arm covers, leggings and shirts

Abstract

To provide a knitted fabric structure, socks, an arm cover, leggings, and a shirt, which can suppress bacterial growth.SOLUTION: A knitted fabric structure of the present disclosure includes a piezoelectric material and is formed of a piezoelectric yarn 1, which generates surface potential by external force from the outside, and an elastic yarn 2 having elastic property. The piezoelectric yarn is mixed at a mixing ratio of 5% or more based on the entire knitted fabric structure.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to knitted fabric structures, socks, arm covers, leggings and shirts. [Background technology]

[0002] Socks using piezoelectric fibers have been disclosed in the past (Patent Document 1). Patent Document 1 also discloses that the socks (or supporters) expand and contract along the joints as the wearer walks, generating an electric charge in the piezoelectric yarn and inhibiting the growth of bacteria. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2017 / 212836 Summary of the Invention [Problem to be solved by the invention]

[0004] Although the socks disclosed in Patent Document 1 have a reasonable effect in inhibiting bacterial growth, the need for knitted fabric structures that inhibit bacterial growth continues, and there is still room for further improvement.

[0005] Therefore, an object of the present disclosure is to provide a knitted fabric structure, socks, arm covers, leggings, and shirts that can inhibit the growth of bacteria. [Means for solving the problem]

[0006] The present inventors attempted to solve the above problems by taking a new approach, rather than simply extending the conventional technology. Specifically, they focused on the fact that a "yarn comprising an electric field-forming filament" generates an electric field by receiving external energy (such as tension or stress), and that this electric field generates an electric potential, which can have an antibacterial effect, for example.

[0007] The knitted fabric structure of the present disclosure comprises: a piezoelectric yarn that includes a piezoelectric material and generates a surface potential in response to an external force; and an elastic yarn having stretchability, The piezoelectric yarn is mixed at a rate of 5% or more based on the total knitted fabric structure.

[0008] Also, socks of the present disclosure use the knitted fabric structure of the present disclosure described above. Also, leggings of the present disclosure use the knitted fabric structure of the present disclosure described above. Also, arm covers of the present disclosure use the knitted fabric structure of the present disclosure described above. Also, shirts of the present disclosure use the knitted fabric structure of the present disclosure described above. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide knitted fabric structures, socks, arm covers, leggings, and shirts that can inhibit the growth of bacteria. Note that the effects described in this specification are merely examples and are not limiting, and additional effects may also be provided. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram of a knitted fabric structure of the present disclosure. [Figure 2] FIG. 2(A) is a diagram showing the structure of thread 1 (S thread), FIG. 2(B) is a cross-sectional view taken along line AA in FIG. 2(A), and FIG. 2(C) is a cross-sectional view taken along line BB in FIG. 2(A). [Figure 3] 3(A) and 3(B) are diagrams showing the relationship between the uniaxial stretching direction of polylactic acid, the direction of the electric field, and the deformation of the electric field forming filament 10. FIG. [Figure 4] Figure 4(A) is a diagram showing the structure of thread 1' (Z thread), Figure 4(B) is a cross-sectional view taken along line AA in Figure 4(A), and Figure 4(C) is a cross-sectional view taken along line BB in Figure 4(A). [Figure 5]FIG. 5 is a cross-sectional view that schematically shows a cross section of a yarn that has a dielectric 100 around an electric field forming filament 10. [Figure 6] FIG. 6(A) is a schematic diagram of a sock using the knitted fabric structure of the present disclosure, and FIG. 6(B) is a schematic diagram showing the sole of a sock using the knitted fabric structure of the present disclosure. [Figure 7] FIG. 7 is a schematic diagram of leggings using the knitted fabric structure of the present disclosure. [Figure 8] FIG. 8 is a schematic diagram of an arm cover using the knitted fabric structure of the present disclosure. [Figure 9] FIG. 9 is a schematic diagram of a shirt using the knitted fabric structure of the present disclosure. [Figure 10] FIG. 10 is a schematic diagram illustrating a method for evaluating the stretchability of a knitted fabric structure according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] The knitted fabric structure, socks, arm covers, leggings, and shirt of the present disclosure are described below. While the description will refer to drawings as necessary, the illustrated contents are merely schematic and illustrative for understanding the present disclosure, and the appearance and dimensional ratios may differ from the actual products. Note that, unless otherwise specified, various numerical ranges referred to in this specification are intended to include the lower and / or upper limits. For example, a numerical range such as 1 to 10 can be interpreted as including both the lower limit of "1" and the upper limit of "10." Furthermore, various numerical values ​​may be accompanied by the terms "about" or "approximately," and these terms mean that the range may include a variation of a few percent, for example, ±10%, ±5%, ±3%, ±2%, or ±1%.

[0012] As shown in FIG. 1, the knitted fabric structure A of the present disclosure includes, for example, a piezoelectric yarn 1 that contains a polymeric piezoelectric material and generates a surface potential when exposed to external energy, and a stretchable elastic yarn 2. Here, the term "knitted fabric" as used herein refers to a structure having a structure in which multiple loops are interconnected, i.e., a sheet-like structure having a knit structure. For example, a knitted fabric can be knitted by creating a loop (e.g., a loop-shaped portion) of yarn and then continuously hooking the next loop onto that loop to form a surface or structure. More specifically, knitted fabrics may have a structure that can be formed by weft knitting, warp knitting, circular knitting, tubular knitting, or sock knitting. Such knitted fabrics also include tricot and raschel knitting. Knitted fabrics of the present disclosure also include sewn products such as cut-and-sewn and knit-and-sewn. Furthermore, non-sewn products such as whole garment knitting are also included in the knitted fabrics of the present disclosure (WHOLEGARMENT®). In other words, the knitted fabrics of the present disclosure are distinctly different from woven fabrics in which warp and weft yarns intersect at right angles to form a fabric.

[0013] Examples of weaves that may be included in the knitted fabric of the present disclosure include, but are not limited to, jersey (also called plain 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 rib knit. The front and back of the knitted fabric may have different weaves. The weave may also include "tucks." In other words, tuck knitting may also be used. The weave may also include "misses." The knitted fabric may be either reverse pile or fleece-backed. Depending on the weave, the feel, breathability, stretchability, etc. of the fabric can be changed.

[0014] In this disclosure, a structure including the minimum repeating units of "knits," and optionally "tucks" and / or "misses" is referred to as a "complete structure."

[0015] Such a structure may be formed by using a knitting machine or by hand knitting. When a knitting machine is used, there is no particular limitation on the type, and any conventionally known knitting machine can be used without particular limitation.

[0016] -Piezoelectric yarn- First, the piezoelectric yarn 1 will be described with reference to Figures 2 to 4. The piezoelectric yarn 1 comprises "electric field-forming filaments 10" (or fibers capable of forming an electric field by surface charge). There are no particular restrictions on the number of electric field-forming filaments 10, and the yarn of the present disclosure may contain, for example, 2 or more, 2 to 500, preferably 10 to 350, and more preferably about 20 to 200 electric field-forming filaments.

[0017] In this disclosure, "electric field-generating filament" basically means, as described above, "a fiber (filament) that can generate an 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, also referred to as "electric potential-generating fiber," "electric 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 electric field-generating filament. The term "electric potential-generating filament" can be used essentially synonymously with "electric field-generating filament."

[0018] "External energy" includes, for example, external forces (hereinafter sometimes referred to as "external forces"), specifically forces that cause deformation or distortion in the piezoelectric yarn 1 or electric field-forming filament 10 and / or forces acting in the axial direction of the piezoelectric yarn 1 or electric field-forming filament 10, more specifically external forces such as tension (e.g., tensile force in the axial direction of the piezoelectric yarn 1 or electric field-forming filament 10) and / or stress or strain force (tensile stress or tensile strain acting on the piezoelectric yarn 1 or electric field-forming filament 10) and / or forces acting in the transverse direction of the piezoelectric yarn 1 or electric field-forming filament 10.

[0019] In the piezoelectric yarn 1, the surface potential generated by the application of an external force may be, for example, 0.1 V or more, preferably 1.0 V or more (either positive or negative potentials can be generated). When the surface potential is 0.1 V or more, the knitted fabric structure A of the present disclosure can suppress bacterial growth. Here, 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. Furthermore, the surface potential may have a direct bactericidal or virucidal effect, or it may have an effect of repelling bacteria and viruses by generating a potential opposite to the potential of bacteria, fungi, and other microorganisms and viruses.

[0020] There are no particular limitations on the dimensions (length, thickness (diameter), etc.) or shape (cross-sectional shape, etc.) of the electric field-forming filament 10. A piezoelectric yarn 1 having such an electric field-forming filament 10 may include a plurality of electric field-forming filaments 10 of different thicknesses. Therefore, the diameter of the piezoelectric yarn 1 may or may not be constant in the length direction.

[0021] The electric field forming filament 10 may be a long fiber or a short fiber. The electric field 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.

[0022] There is no particular limitation on the thickness (diameter) of the electric field forming filament 10, and it may or may not be the same (constant) along the length of the electric field forming filament 10. The electric field 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.

[0023] Furthermore, the fiber strength of the piezoelectric yarn 1 is preferably 1 to 10 cN / dtex. This allows the piezoelectric yarn 1 to withstand large deformations caused by the generation of a high potential without breaking. The fiber strength is more preferably 1 to 7 cN / dtex, and most preferably 1 to 5 cN / dtex. For the same reason, the elongation of the piezoelectric yarn 1 is preferably 10 to 50%.

[0024] The shape of the electric field forming filament 10, particularly the cross-sectional shape, is not particularly limited, and may be, for example, circular, elliptical, rectangular, or irregular in cross section. A circular cross-sectional shape is preferred.

[0025] The electric field-forming filament 10 preferably comprises, for example, a material (hereinafter sometimes referred to as a "piezoelectric material" or "piezoelectric body") that has the piezoelectric effect (polarization phenomenon due to external force) or piezoelectricity (the property of generating voltage when mechanical strain is applied, or conversely, generating mechanical strain when voltage is applied). Among these, it is particularly preferable to use fibers (hereinafter sometimes referred to as "piezoelectric fibers") that comprise piezoelectric materials. Because piezoelectric fibers can generate an electric field through piezoelectricity, they do not require a power source and there is no risk of electric shock. Furthermore, the lifespan of the piezoelectric material contained in piezoelectric fibers is longer than, for example, the antibacterial effect of drugs. Furthermore, such piezoelectric fibers are less likely to cause allergic reactions.

[0026] The "piezoelectric material" can be any material that has a piezoelectric effect or piezoelectricity, and may be an inorganic material such as piezoelectric ceramics, or an organic material such as polymers.

[0027] The "piezoelectric material" (or "piezoelectric fiber") preferably comprises a "piezoelectric polymer." Examples of the "piezoelectric polymer" include a "piezoelectric polymer having pyroelectric properties" and a "piezoelectric polymer without pyroelectric properties."

[0028] "Piezoelectric polymer with pyroelectric properties" generally refers to a piezoelectric material made of a polymer material that has pyroelectric properties and can generate an electric charge (or electric potential) on its surface simply by applying a temperature change. Examples of such piezoelectric polymers include polyvinylidene fluoride (PVDF). In particular, those that can generate an electric charge (or electric potential) on their surface using the thermal energy of the human body are preferred.

[0029] "Piezoelectric polymers without pyroelectric properties" generally refer 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 polylactic acids include poly-L-lactic acid (PLLA) formed by polymerizing L-monomers and poly-D-lactic acid (PDLA) formed by polymerizing D-monomers.

[0030] In addition, the piezoelectric yarn 1 may be configured as an electric field-forming filament 10 (or charge-generating fiber) using a conductor as the core yarn, wrapping (covering) an insulator around the conductor, and applying a voltage to the conductor to generate an electric charge.

[0031] The piezoelectric yarn 1 may be a yarn obtained by simply pulling and aligning a plurality of electric field-generating filaments 10 (pulled yarn or untwisted yarn), 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 for twisting, crimping, or spinning the yarn, and any conventionally known method can be used.

[0032] For example, as shown in FIG. 2(A), the piezoelectric yarn 1 can also be constructed by twisting together multiple electric field-forming filaments 10. In the embodiment shown in FIG. 2(A), the piezoelectric yarn 1 is a left-handed yarn (hereinafter referred to as an "S yarn") in which the electric field-forming filaments 10 are twisted by turning counterclockwise, but it may also be a right-handed yarn (hereinafter referred to as a "Z yarn") in which the electric field-forming filaments 10 are twisted by turning clockwise (see, for example, the piezoelectric yarn 1' in FIG. 4(A)). Thus, when the piezoelectric yarn 1 is a twisted yarn, it may be either an "S yarn" or a "Z yarn."

[0033] In the piezoelectric yarn 1, the spacing between the electric field forming filaments 10 is about 0 μm to about 10 μm, and generally about 5 μm. When the spacing between the electric field forming filaments 10 is 0 μm, this means that the electric field forming filaments are in contact with each other.

[0034] In order to describe the piezoelectric yarn 1 in detail below, an example of the piezoelectric yarn 1 will be described in more detail with reference to Figures 2 to 4, taking as an example an embodiment in which the electric field-forming filament 10 contains a piezoelectric material, and the piezoelectric material is "polylactic acid."

[0035] Polylactic acid (PLA), which can be used as a piezoelectric material, is a chiral polymer with a helical main chain structure. When polylactic acid is uniaxially stretched and the molecules are oriented, it can exhibit piezoelectricity. Furthermore, if the crystallinity is increased by heat treatment, the piezoelectric constant increases. Increasing the crystallinity in this way can improve the surface potential value.

[0036] The optical purity (enantiomeric excess (ee)) of polylactic acid (PLA) can be calculated using the following formula. Optical purity (%)={|L volume - D volume| / (L volume + D volume)}×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 to 100% by weight, even more preferably 99.0% by weight to 100% by weight, and particularly preferably 99.0% by weight to 99.8% by weight. The amounts of the L- and D-isomers of polylactic acid (PLA) can be determined, for example, by high-performance liquid chromatography (HPLC).

[0037] As shown in Figure 2(A), when the thickness direction is defined as the first axis, the stretching direction 900 is defined as the third axis, and the direction perpendicular to both the first axis and the third axis is defined as the second axis, the electric field forming filament (or piezoelectric fiber) 10 comprising uniaxially stretched polylactic acid has tensor components d14 and d25 as the piezoelectric strain constants.

[0038] Therefore, polylactic acid can generate electric charge (or potential) most efficiently when strain occurs in a direction at 45 degrees to the uniaxially stretched direction.

[0039] 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 weight is not limited to these values.

[0040] 3(A) and 3(B) are diagrams showing the relationship between the uniaxial stretching direction of polylactic acid, the electric field direction, and the deformation of fibers containing electric field-forming filaments 10 and / or piezoelectric yarns 1. FIG.

[0041] As shown in FIG. 3(A), when the electric field-forming filament 10 contracts 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 a direction from the back side to the front side of the paper. That is, the electric field-forming filament 10 can generate a negative charge on the front side of the paper. As shown in FIG. 3(B), when the electric field-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 it can generate an electric field in a direction from the front side of the paper to the back side. That is, the electric field-forming filament 10 can generate a positive charge on the front side of the paper.

[0042] Because polylactic acid can become piezoelectric through molecular orientation by stretching, it does not require poling, as is the case with other piezoelectric polymers such as polyvinylidene fluoride (PVDF) or piezoelectric ceramics. The piezoelectric constant of uniaxially stretched polylactic acid is approximately 5-30 pC / N, which is extremely high among polymers. Furthermore, the piezoelectric constant of polylactic acid does not fluctuate over time and is extremely stable.

[0043] The electric field-forming filament 10 is preferably a fiber having a circular cross section. The electric field-forming filament 10 can be produced by, for example, extrusion molding a piezoelectric polymer to form a fiber; melt-spinning a piezoelectric polymer to form a fiber (including, for example, a spinning-drawing method in which the spinning and drawing steps are performed separately, a straight-drawing method in which the spinning and drawing steps are combined, a POY-DTY method in which a false twisting step can also be performed simultaneously, or an ultra-high-speed spinning method aimed at high speed); dry- or wet-spinning a piezoelectric polymer to form a fiber (including, for example, a phase separation method or wet-dry spinning method in which a raw polymer is dissolved in a solvent and extruded through a nozzle to form a fiber; a gel spinning method in which a solvent-containing gel is uniformly formed into a fiber; or a liquid crystal spinning method in which a liquid crystal solution or melt is used to form a fiber); or electrostatic spinning a piezoelectric polymer to form a fiber. The cross-sectional shape of the electric field-forming filament 10 is not limited to a circular shape.

[0044] For example, the piezoelectric yarn 1 shown in Fig. 2 may be a yarn (multifilament yarn) (S yarn) made by twisting a plurality of electric field-forming filaments 10 containing such polylactic acid (the twisting method is not particularly limited). The extension direction 900 of each electric field-forming filament 10 coincides with the axial direction of the respective electric field-forming filament 10. Therefore, the extension direction 900 of the electric field-forming filament 10 is tilted to the left with respect to the axial direction of the piezoelectric yarn 1. This angle depends on the number of twists.

[0045] 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 1, 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.

[0046] The piezoelectric yarn 1 can generate an electric field due to the potential difference that can be generated by this charge. This electric field can also leak into the surrounding space and form a coupled 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 having a predetermined potential (including ground potential), such as a human body, when the piezoelectric yarn 1 is in proximity to the object.

[0047] 4, since the piezoelectric yarn 1' is a Z-yarn, the extension direction 900 of the electric field-forming filament (or piezoelectric fiber) 10 is tilted to the right with respect to the axial direction of the piezoelectric yarn 1'. Note that this angle depends on the number of twists of the yarn.

[0048] When an "external force", such as tension (preferably axial tension) or stress (preferably axial tensile stress), is applied to such a piezoelectric yarn 1', which is a Z-thread, a positive (+) charge (or potential) is generated on the surface of the piezoelectric yarn 1', and a negative (-) charge (or potential) can be generated inside it.

[0049] The piezoelectric yarn 1' can also generate an electric field due to the potential difference that can be generated by this charge. This electric field can leak into the nearby space and form a coupled 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 having a predetermined potential (including ground potential), such as a human body, when the piezoelectric yarn 1' is placed near the object.

[0050] Furthermore, when piezoelectric yarn 1, which is an S-yarn, and piezoelectric yarn 1', which is a Z-yarn, are brought close to each other, an electric field can be generated between piezoelectric yarn 1 and piezoelectric yarn 1'.

[0051] The polarities of the electric charges (or potentials) generated in the piezoelectric yarn 1 and the piezoelectric yarn 1' 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 complex entanglement of fibers, or a circuit that can be formed by a current path that can be accidentally formed in the yarn due to moisture, etc.

[0052] The piezoelectric yarn 1 and the piezoelectric yarn 1' can be better understood by reading Japanese Patent No. 6428979, which is incorporated herein by reference.

[0053] In the piezoelectric yarn 1, the electric field-forming filaments 10 are preferably made of polylactic acid (PLA). When the electric field-forming filaments 10 contain a piezoelectric material such as polylactic acid, the surface potential can be more appropriately controlled. Furthermore, because polylactic acid is hydrophobic, it can provide a smooth feel against the skin, thereby imparting comfort to the knitted structure. Furthermore, because polylactic acid is known as a biodegradable plastic, it can eventually decompose into CO2 and water, reducing the burden on the environment.

[0054] The 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 crystallinity can be determined by measurement methods such as differential scanning calorimetry (DSC), X-ray diffraction (XRD), and wide-angle X-ray diffraction (WAXD). Within this range, the piezoelectricity derived from polylactic acid crystals is enhanced, allowing for more effective polarization due to the piezoelectricity of polylactic acid. It has been found in the present disclosure that the measured crystallinity values ​​measured using WAXD differ from those measured using DSC by a factor of approximately 1.5 (DSC measured value / WAXD measured value ≈ 1.5).

[0055] The piezoelectric yarn 1 does not contain additives such as plasticizers or lubricants. It is generally known that when piezoelectric yarn 1 contains additives, it tends to be difficult to generate a surface potential. 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" refers to a material that imparts flexibility to the piezoelectric yarn 1, and a "lubricant" refers to a material that improves the molecular slippage 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.

[0056] The piezoelectric yarn 1 should not be construed as being limited to the above-described embodiments, particularly to yarns that may be made from polylactic acid. Furthermore, there are no particular limitations on the manufacturing method of the piezoelectric yarn 1, and it is not limited to the manufacturing method described above.

[0057] Other aspects of piezoelectric yarn Furthermore, the piezoelectric yarn 1 may have a "dielectric" provided around the electric field-forming filament 10. For example, as shown schematically in the cross-sectional view of Figure 5, a dielectric 100 may be provided around the electric field-forming filament (or piezoelectric fiber) 10.

[0058] In this disclosure, the term "dielectric" refers to a material or substance that has "dielectricity" (the property of being electrically polarized positively or negatively (or dielectric polarization or electric polarization) by an electric field), and can store electric charges on its surface.

[0059] The dielectric 100 may be present in the longitudinal direction and circumferential direction of the electric field forming filament 10, and may completely or partially cover the electric field forming filament 10. When the electric field forming filament 10 is partially covered with the dielectric 100, the electric field forming filament 10 itself may be exposed in the uncovered portion.

[0060] Therefore, the dielectric 100 may be provided over the entire area or partly in the longitudinal direction of the electric field forming filament 10. Furthermore, the dielectric 100 may be provided over the entire area or partly in the circumferential direction of the electric field forming filament 10.

[0061] Furthermore, the thickness of the dielectric 100 may be uniform or non-uniform (see, for example, FIG. 5).

[0062] The dielectric 100 may be present between multiple electric field forming filaments 10, and in this case, there may be a portion where the dielectric 100 is not present between multiple electric field forming filaments 10. Also, bubbles or cavities may be present in the dielectric 100.

[0063] There are no particular limitations on the dielectric 100 as long as it includes a material or substance having dielectric properties. Dielectric materials (e.g., oils, antistatic agents, etc.) known to be usable as surface treatment agents (or fiber treatment agents) mainly in the textile industry may be used as the dielectric 100.

[0064] In the piezoelectric yarn 1, the dielectric 100 preferably contains an oil. The oil may be an oil (spinning oil) used as a surface treatment (or fiber treatment) in the production of the electric field-forming filament 10 (e.g., an anionic, cationic, or nonionic surfactant). Alternatively, an oil (e.g., an anionic, cationic, or nonionic surfactant) used as a surface treatment (or fiber treatment) in the fabric-making process (e.g., knitting, weaving, etc.) or an oil (e.g., an anionic, cationic, or nonionic surfactant) used as a surface treatment (or fiber treatment) in the finishing process may also be used. While the filament production process, fabric-making process, and finishing process are given here as typical examples, the present invention is not limited to these processes. The oil is preferably an oil used to reduce friction of the electric field-forming filament 10.

[0065] Examples of oils include the Delion series manufactured by Takemoto Yushi Co., Ltd., the Marposol series and Marposize series manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd., and the Paratex series manufactured by Marubishi Yuka Kogyo Co., Ltd.

[0066] The oil may be present entirely or at least partially along the electric field-forming filament 10. After the electric field-forming filament 10 is processed into the piezoelectric yarn 1, at least some or all of the oil may be removed from the electric field-forming filament 10 by washing.

[0067] Furthermore, the dielectric 100 used to reduce friction of the electric field forming filaments 10 may be a surfactant such as a detergent or fabric softener used in laundry.

[0068] 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.

[0069] 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.

[0070] The dielectric 100 may be conductive (conductive), 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 production of the electric field forming filament 10 can be used. As the antistatic agent, it is preferable to use an antistatic agent that is particularly used to reduce the fraying of the electric field forming filament 10.

[0071] Examples of antistatic agents include the Kapron series manufactured by Nisshin Chemical Laboratory Co., Ltd., and the Nicepol series and Daytron series manufactured by Nicca Chemical Co., Ltd.

[0072] The antistatic agent may be present entirely or at least partially along the electric field-forming filament 10. After the electric field-forming filament 10 is processed into the piezoelectric yarn 1, at least some or all of the antistatic agent may be removed from the electric field-forming filament 10 by washing.

[0073] Furthermore, 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 electric field-forming filaments 10. In other words, the electric field-forming filaments 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 this case, the air (or air layer) present between the electric field-forming filaments 10 can function as a dielectric. Therefore, in this case, the dielectric comprises air.

[0074] For example, a piezoelectric yarn 1 that does not contain the above-mentioned surface treatment agent (or fiber treatment agent), detergent, fabric softener, etc., can be used by treating a yarn that has the above-mentioned oil agent, antistatic agent, or other surface treatment agent (or fiber treatment agent) attached around the electric field-forming filaments 10 by washing or immersion in a solvent. In this case, the pure electric field-forming filaments 10 are exposed. Alternatively, in the present disclosure, a piezoelectric yarn 1 that includes only pure electric field-forming filaments 10 can be used.

[0075] In addition, in the present disclosure, a yarn may be used in which the surface treatment agents (or fiber treatment agents) such as the above-mentioned oils and antistatic agents, detergents, fabric softeners, etc. have been partially removed by treatment such as washing or solvent immersion, thereby partially exposing the pure electric field-forming filaments 10.

[0076] The thickness of the dielectric 100 (or the spacing between the electric field 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 generally about 5 μm.

[0077] -Elastic thread- Next, the elastic yarn 2 will be described. Elastic yarn refers to a yarn with elasticity, and "elasticity" as used herein refers to a stretch recovery rate of 40% or more. The stretch recovery rate is a value measured in accordance with "JIS L 1096 Fabric Testing Methods for Woven and Knit Fabrics," where 100% is when the fabric has recovered to its original length and 0% is when the fabric remains at the stretched length. Furthermore, "elasticity" may be determined based on a test method such as "JIS L 1096 Fabric Testing Methods for Woven and Knit Fabrics." Here, a knitted fabric structure made solely of the piezoelectric yarn 1 described above would have poor stretchability and be uncomfortable to wear. Therefore, the knitted fabric structure contains an elastic yarn 2 in addition to the piezoelectric yarn 1 (see FIG. 1).

[0078] Preferable elastic yarn 2 includes any yarn selected from the group consisting of yarn using polyurethane as a core yarn, wooly-processed nylon yarn, and polytrimethylene terephthalate.

[0079] There are no particular limitations on the dimensions (length, thickness (diameter), etc.) or shape (cross-sectional shape, etc.) of the elastic yarn 2. The elastic yarn 2 may be either long fibers or short fibers.

[0080] In this way, when the elastic yarn 2 is contained in the knitted fabric structure of the present disclosure, the stretchability of the knitted fabric structure is ensured, improving comfort when worn. Furthermore, because the fabric itself is stretchable, the piezoelectric yarn 1 also stretches in response to the stretching of the elastic yarn 2. This applies energy (external force) to the piezoelectric yarn 1, which can generate a surface potential on the knitted fabric structure.

[0081] -Other additional configurations- The knitted fabric structure of the present disclosure may contain yarns made of natural fibers and / or chemical fibers in addition to the piezoelectric yarn 1 and elastic yarn 2 described above. Specific examples of natural fibers include cotton, silk, linen, and / or wool, and the inclusion of these natural fibers provides a pleasant feel and / or comfort to the skin, as well as good moisture absorption and breathability. Specific examples of chemical fibers include nylon, acrylic, and / or rayon, and the inclusion of these chemical fibers can improve the durability of the knitted fabric structure.

[0082] -Knitted fabric structure blend ratio- In the knitted structure of the present disclosure, which includes the above-described piezoelectric yarn 1 and elastic yarn 2, the piezoelectric yarn 1 is mixed at a mixing ratio of 5% or more based on the entire knitted fabric structure. This numerical range allows for appropriate suppression of bacteria and viruses. The basis for this numerical range will be explained in detail in the examples below.

[0083] Furthermore, in an embodiment of the knitted fabric structure A of the present disclosure, the piezoelectric yarn 1 preferably accounts for 65% or less of the entire knitted fabric structure. In other words, it is preferable that yarns other than the piezoelectric yarn 1 (for example, elastic yarn 2 and yarns such as cotton) account for 35% or more of the entire knitted fabric structure A. If the knitted fabric structure A contains at least about 35% of yarns other than the piezoelectric yarn 1, the stretchability of the knitted fabric structure A can be ensured compared to a knitted fabric structure made only of piezoelectric yarns, and the comfort of wearing the knitted fabric structure A can be improved.

[0084] -Specific form of knitted fabric structure- Next, specific embodiments of the knitted fabric structure of the present disclosure will be described. The knitted fabric structure of the present disclosure may be used in a form selected from the group consisting of socks (see FIG. 6), leggings (see FIG. 7), arm covers (see FIG. 8), and shirts (see FIG. 9).

[0085] In a preferred embodiment of the knitted fabric structure, the piezoelectric yarn 1 is arranged in a position where it will stretch when worn. By arranging the piezoelectric yarn 1 in this way, the piezoelectric yarn 1 can easily stretch and generate a surface potential. Therefore, the generation of the surface potential can suppress bacteria and viruses. Specific knitted fabric structures are described below.

[0086] 1. Socks When the knitted fabric structure is a sock (see FIG. 6), the base of the toes flexes during walking, stretching the piezoelectric yarn 1. Therefore, the term "sock" in this specification refers to a bag-shaped piece of fabric that covers the foot or the foot and lower leg (lower leg, upper leg). Examples of socks include socks, stockings (garter stockings, non-garter stockings, etc.), pantyhose, etc. Socks also include foot covers (pump socks) such as low-cut foot covers and high-cut foot covers, anklets, crew socks, knee socks, and over-the-knee socks of various lengths. Five-toe socks with a fork for the toes and tabi-style socks with a fork are also included.

[0087] In a preferred embodiment of the sock, the piezoelectric yarn 1 is arranged in the region R (see FIG. 6(B)) from the ball of the foot b toward the toes, so that the piezoelectric yarn 1 expands and contracts with the movement of walking, generating a surface potential. This arrangement of the piezoelectric yarn 1 allows the generation of a surface potential to appropriately suppress bacteria and viruses.

[0088] 2. Leggings When the knitted fabric structure is leggings (see FIG. 7), the piezoelectric yarn 1 can be stretched and contracted by the bending of the hip joint and / or knee joint caused by the movement of walking. Therefore, the term "leggings" as used herein refers to garments that cover the hip joint and / or knee joint. Note that, because the term "leggings" as used herein refers to garments that stretch and contract with movement of at least the hip joint or knee joint, it also includes garments that are longer than the knee joint, such as spats or pants, and leg warmers that stretch and contract with movement of the knee joint.

[0089] In a preferred embodiment of leggings, the piezoelectric yarn 1 is arranged in the hip and / or knee joint areas so that the piezoelectric yarn 1 expands and contracts with the movement of walking, generating a surface potential. This arrangement of the piezoelectric yarn 1 allows the generation of a surface potential to appropriately suppress bacteria and viruses.

[0090] 3. Arm covers When the knitted fabric structure is an arm cover (see FIG. 8), the piezoelectric yarn 1 can be stretched and contracted by arm movement (movement of the elbow joint, shoulder joint, and / or wrist). Therefore, the term "arm cover" as used herein refers to an article worn to cover the elbow joint, shoulder joint, and / or wrist. Note that the term "arm cover" as used herein refers to an article worn that stretches and contracts in response to movement of at least the elbow joint, shoulder joint, and / or wrist, and therefore also includes, for example, gloves.

[0091] In a preferred embodiment of the arm cover, the piezoelectric yarn 1 is arranged in the hip and / or knee joint areas so that the piezoelectric yarn 1 expands and contracts with the movement of walking, generating a surface potential. This arrangement of the piezoelectric yarn 1 allows the generation of a surface potential to appropriately suppress bacteria and viruses.

[0092] 4. Shirt When the knitted fabric structure is a shirt (see FIG. 9), the piezoelectric yarn 1 can be stretched and contracted by the movement of the upper body. Therefore, the term "shirt" as used in this specification refers to an article of clothing that can be worn on the upper body. For example, it is preferable to provide the piezoelectric yarn 1 in the armpits of a shirt, where sweat tends to accumulate and bacteria are likely to grow. The placement of the piezoelectric yarn 1 makes it possible to appropriately suppress bacteria and viruses by generating a surface potential. Note that the placement of the piezoelectric yarn 1 is not limited to the armpits, but may also be provided in areas where the shirt stretches and contracts with the movement of the upper body, such as the back, waist, knees, wrists, neck, chest, and / or abdomen. [Example]

[0093] A demonstration test was conducted on the bacteria-inhibiting effect of the knitted fabric structure of the present disclosure.

[0094] -Example of socks- As the knitted fabric structures, socks described in Examples 1 to 5 and Comparative Example shown in Table 1 below were manufactured.

[0095] [Table 1] "FTY (Filament Twisted Yarn)" in the table refers to a processed yarn in which long fiber filament yarn such as nylon is wrapped around a stretchy polyurethane elastic yarn.

[0096] In conducting the demonstration test, the stretchability of the socks of the comparative example and examples 1 to 5 was first evaluated. The stretchability was calculated by adding up the "stretchability ratio when wearing socks" and the "stretchability ratio when walking with socks" in the longitudinal direction of the sole. The "stretchability ratio when wearing socks" was approximately 15%, and the "stretchability ratio when walking with socks" was approximately 35%. In other words, it was found that the total stretchability ratio of the socks in the longitudinal direction of the sole was approximately 50% (15% + 30% + error).

[0097] The stretchability was evaluated using a non-contact optical three-dimensional strain measurement system (GOM's 3D system solution "ARAMIS") to analyze image data of a mannequin (foot length 24-27 cm, foot width 9.1-9.7 cm, instep circumference 23-25 ​​cm, foot circumference 23-25 ​​cm) wearing the socks, and the result was calculated to be approximately 15%. Furthermore, the "stretchability rate when walking with socks on" was measured using a non-contact optical three-dimensional strain measurement system (GOM's 3D system solution "ARAMIS") to analyze image data of a mannequin wearing the socks and walking, and the stretchability rate was calculated to be approximately 30% based on the results of similar image analysis, since it is known that when walking, the angle between the foot and the floor is approximately 55° with the base of the toes flexed, as shown in Figure 10.

[0098] Furthermore, since the above elasticity evaluation revealed that the total elasticity of the socks was approximately 50%, the surface potential of the socks at this elasticity was measured. The evaluation results are shown in Table 2. The surface potential was evaluated using a method using the potential measuring device described in Japanese Patent Application No. 2021-065673.

[0099] [Table 2] (Surface potential for socks with a stretch rate of approximately 50%)

[0100] According to the results in Table 2, the socks of Examples 1 to 5 generated a surface potential of 0.1 V or more. On the other hand, the socks of the comparative example did not contain piezoelectric yarn 1, and therefore no surface potential was generated.

[0101] Next, an antibacterial test was carried out on the socks of the comparative example and examples 1 to 5. The details of the antibacterial test are as follows. (1) The viable bacterial count is measured for the socks of the Comparative Example and Examples 1 to 5 in the initial state. (2) The socks of the comparative example and examples 1 to 5 are left to stand for 18 hours, and then the viable bacterial count is measured. (3) After leaving the socks of Comparative Example and Examples 1 to 5 for 18 hours, the socks are stretched and contracted continuously for 18 hours to generate a surface potential, and then the number of viable bacteria is measured. The viable cell count was evaluated based on the JIS L1902 method, as described in Japanese Patent Nos. 6922546 and 6292368. The results of viable cell count measurements are shown in Table 3. The values ​​in the table indicate the logarithm of the Colony Forming Unit (logarithm of colonies per gram).

[0102] [Table 3]

[0103] According to the results in Table 3, the socks of Examples 1 to 5 had a difference of -2 or more between the viable bacterial count after 18 hours of stretching (T3) and the viable bacterial count after 18 hours of standing (T3), indicating an effective reduction in bacteria, while the socks of the comparative example showed an increase in bacteria. This indicates that bacterial growth could be suppressed by stretching the piezoelectric yarn 1 to generate a surface potential.

[0104] -Example of leggings- The leggings described in Examples 6 and 7 shown in Table 4 below were manufactured as the knitted fabric structures and subjected to the antibacterial test described above. The stretch rate of the leggings was set to 39%, which is different from the stretch rate of socks (approximately 50%). This is due to the difference in the mobility of the toes in socks and the mobility of the knee joint or hip joint in leggings.

[0105] [Table 4] "DCY (Double Covered Yarn)" in the table refers to a textured yarn in which other spun yarns or filament yarns are wound twice in different directions around a polyurethane elastic yarn. Also, "face yarn" in the table refers to the yarn exposed on the face side of the fabric, "back yarn" refers to the yarn exposed on the back side of the fabric, and "insertion yarn" refers to the yarn placed between the face yarn and back yarn and inserted into the face yarn loops and back yarn loops.

[0106] According to the results in Table 4, the leggings of Examples 6 and 7 showed an effective reduction in bacteria according to the results of T3-T2.

[0107] -Example of arm cover- The knitted fabric structure was the arm cover described in Example 8 in Table 5 below, and the antibacterial test described above was carried out. The stretch rate of the arm cover was set to 45%, which is different from the stretch rate of socks (approximately 50%). This is because the mobility of the toes in socks differs from the mobility of the elbow joint in arm covers.

[0108] [Table 5]

[0109] According to the results in Table 5, the arm cover of Example 8 effectively reduced bacteria according to the results of T3-T2.

[0110] -Example of shirt- The shirts described in Examples 9 to 11 shown in Table 6 below were manufactured as knitted fabric structures, and the antibacterial test described above was carried out. The stretch rate of the shirts was set to 17%, which is different from the stretch rate of the socks (approximately 50%). This is due to the difference in the mobility of the toes in socks and the mobility of the shoulder joints in shirts.

[0111] [Table 6] "PTT (Polytrimethylene terephthalate)" in the table refers to yarn made from polytrimethylene terephthalate, a type of elastic polyester.

[0112] According to the results in Table 6, the shirts of Examples 9 to 11 showed an effective reduction in bacteria according to the results of T3 and T2.

[0113] It should be noted that the embodiments disclosed herein are illustrative in all respects and are not intended to be limiting. Therefore, the technical scope of the present invention should not be interpreted solely by the above-described embodiments, but should be defined based on the claims. The technical scope of the present invention also includes all modifications within the scope and meaning equivalent to the claims. [Explanation of symbols]

[0114] 1,1' Piezoelectric yarn 2 Elastic thread 10 Electric field forming filament 100 Dielectric 20 Elastic thread 900 Stretching direction 910A 1st diagonal 910B 2nd diagonal 100 A knitted fabric structure A1 socks A2 Leggings A3 Arm Covers A4 shirt b Ball of the foot

Claims

1. The knitted fabric structure includes a piezoelectric yarn containing polylactic acid, which contains a piezoelectric material and generates a surface potential when subjected to an external force, and an elastic yarn having stretchability, and the piezoelectric yarn is mixed at a mixing rate of 5% to 65% based on the entire knitted fabric structure, A knitted fabric structure, wherein the elastic yarn is any yarn selected from the group consisting of yarn using polyurethane as a core yarn, wooly-processed nylon yarn, and polytrimethylene terephthalate.

2. The knitted fabric structure of claim 1 , wherein the loops of the piezoelectric yarn are hooked onto the loops of the elastic yarn.

3. The knitted fabric structure of claim 1 or 2, wherein the piezoelectric material has a crystallinity of 20% or more.

4. The knitted fabric structure of any one of claims 1 to 3, wherein the piezoelectric material does not contain any additives.

5. The knitted fabric structure according to any one of claims 1 to 4, wherein the surface potential is 0.1 V or more.

6. The knitted fabric structure according to any one of claims 1 to 5, wherein the piezoelectric yarn is arranged in a position that stretches when worn.

7. The knitted fabric structure according to claim 6, wherein the position that stretches when worn is on the toe side of the ball of the foot.

8. A sock using the knitted fabric structure according to any one of claims 1 to 7.

9. Leggings using the knitted fabric structure according to any one of claims 1 to 6.

10. An arm cover using the knitted fabric structure according to any one of claims 1 to 6.

11. A shirt using the knitted fabric structure according to any one of claims 1 to 6.

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