Yarn, method of manufacturing fabric and yarn

Abstract

To provide yarn having high antibacterial effect, and a method of manufacturing a fabric and the yarn.SOLUTION: Yarn of the disclosure is formed so as to have a microvoid MV on a surface of a potential generation filament 10 that generates a potential, by receiving energy from an external part.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present disclosure relates to yarns, fabrics and methods for making the yarns. [Background technology]

[0002] Yarns having fibers that generate a surface potential when subjected to external energy have been proposed (see Patent Documents 1 to 3). The yarns described in Patent Documents 1 to 3 can exhibit an antibacterial effect by generating a surface potential defined under predetermined conditions. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2017 / 212836 [Patent Document 2] JP 2018-90950 A [Patent Document 3] JP 2019-131948 A Summary of the Invention [Problem to be solved by the invention]

[0004] Patent documents 1 to 3 disclose a demonstration test in which the number of live bacteria was observed 18 hours after inoculation of a test bacteria. From the viewpoint of practicality, a yarn that exerts an antibacterial effect in a shorter time is desired. Although the yarns described in Patent documents 1 to 3 generate a surface potential (V) defined under given conditions, there is room for improvement to further enhance the antibacterial effect.

[0005] Therefore, an object of the present disclosure is to provide a yarn, a fabric, and a method for manufacturing the yarn that have a high antibacterial effect. [Means for solving the problem]

[0006] The yarn of the present disclosure comprises microvoids on the surface of an electric potential generating filament that generates an electric potential upon receiving external energy.

[0007] The fabric of the present disclosure comprises the above-described yarn.

[0008] The method for producing yarn disclosed herein includes a step of forming microvoids in an electric potential generating filament that generates an electric potential upon receiving external energy. Effect of the Invention

[0009] According to the present disclosure, since microvoids are provided on the surface of the potential generating filament, a strong electric field (V / m) can be generated in the microvoids. Therefore, the strong electric field can effectively exert the antibacterial effect. Note that the effects described in this specification are merely examples and are not limited thereto, and additional effects may also be present. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1(A) is a diagram showing the structure of a yarn (S yarn), FIG. 1(B) is a cross-sectional view taken along line AA in FIG. 1(A), and FIG. 1(C) is a cross-sectional view taken along line BB in FIG. 1(A). [Diagram 2] 2(A) and 2(B) 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-generating filament. [Diagram 3] FIG. 3(A) is a diagram showing the configuration of a yarn (Z yarn), FIG. 3(B) is a cross-sectional view taken along line AA in FIG. 3(A), and FIG. 3(C) is a cross-sectional view taken along line BB in FIG. 3(A). [Figure 4] FIG. 4 is a cross-sectional view that shows a schematic cross section of a yarn having a dielectric around a potential-generating filament. [Diagram 5] FIG. 5 is an SEM photograph of a yarn of the present disclosure. [Figure 6] FIG. 6 is a schematic cross-sectional view of a potential-generating filament having a microvoid. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The yarn, fabric, and yarn manufacturing method of the present disclosure will be described below. Although the description will be made with reference to the drawings as necessary, the contents shown in the drawings are merely schematic and illustrative for understanding the present disclosure, and the appearance and dimensional ratios may differ from the actual ones. In addition, 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 including 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 they may include a variation of several percent, for example, ±10 percent, ±5 percent, ±3 percent, ±2 percent, and / or ±1 percent.

[0012] -Description of the yarn of the present disclosure- The yarn of the present disclosure will now be described. The yarn comprises a potential-generating filament that receives external energy and generates a potential. There is no particular limit to the number of potential-generating filaments 10, and the yarn of the present disclosure may include, for example, only one potential-generating filament, two or more potential-generating filaments, or about 2 to 1000 potential-generating filaments, preferably 10 to 800 potential-generating filaments, and more preferably about 20 to 600 potential-generating filaments.

[0013] [About the potential generating filament] As described above, the term "potential-generating filament" basically means "a fiber (filament) that can generate a charge by external energy (e.g., tension and / or stress, etc.) to form a potential (specifically, a surface potential) and / or an electric field" (hereinafter, it may be referred to as "potential-generating fiber," "potential-forming filament," "potential-forming 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.

[0014] "External energy" includes, for example, an external force (hereinafter sometimes referred to as "external force"), specifically a force that causes deformation or distortion in the thread or potential-generating filament and / or a force applied in the axial direction of the thread or potential-generating filament, more specifically, an external force such as tension (e.g., a tensile force in the axial direction of the thread or potential-generating filament) and / or stress or strain force (tensile stress or tensile strain on the thread or potential-generating filament) and / or a force applied in the transverse direction of the thread or potential-generating filament.

[0015] In the potential-generating filament, the surface potential generated by 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 yarn and / or fabric of the present disclosure can inhibit the growth of bacteria. There is no particular limitation 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 be an effect resulting from repelling bacteria and viruses by generating a potential opposite to the potential of bacteria, fungi, and other fungi and viruses.

[0016] The potential-generating filament is preferably made of a material (hereinafter sometimes referred to as a "piezoelectric material" or "piezoelectric body") having, 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") made of a piezoelectric material. Since the piezoelectric fiber can generate a potential 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, for example, the antibacterial effect of a drug or the like. In addition, such a piezoelectric fiber is less likely to cause an allergic reaction.

[0017] 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 polymer.

[0018] 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 not having pyroelectric properties."

[0019] "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. Examples of such piezoelectric polymers include 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 preferred.

[0020] The term "piezoelectric polymer without pyroelectricity" generally refers to a piezoelectric polymer made of a polymer material, excluding the above-mentioned "piezoelectric polymer with pyroelectricity". 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.

[0021] One example of a piezoelectric material contained in the potential-generating filament 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 applying heat treatment, the piezoelectric constant increases. Increasing the degree of crystallinity in this way can improve the value of the surface potential.

[0022] The optical purity (enantiomeric excess (ee)) of polylactic acid (PLA) can be calculated by 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 values ​​obtained by, for example, a method using high performance liquid chromatography (HPLC).

[0023] 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.

[0024] Since piezoelectricity can be generated in polylactic acid by molecular orientation treatment through stretching, there is no need to perform poling treatment as with other piezoelectric polymers such as polyvinylidene fluoride (PVDF) or piezoelectric ceramics. The piezoelectric constant of uniaxially stretched polylactic acid is about 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.

[0025] The potential-generating filament is preferably a fiber having a circular cross section. The potential-generating filament 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-drawing method in which a spinning step and a drawing step are performed separately, a straight drawing method in which a spinning step and a drawing step are connected, a POY-DTY method in which a false twisting step can also be performed simultaneously, or an ultra-high-speed spinning method for increasing speed), a method of dry- or wet-spinning a piezoelectric polymer (including, for example, a phase separation method or a dry-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 a 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-generating filament is not limited to a circle. For example, the cross section may be a circle, an ellipse, a rectangle, and / or an irregular shape.

[0026] The electric potential-generating filament may be a long fiber or a short fiber. The electric potential-generating filament may have a length (dimension) of, for example, 0.01 mm or more. The length may be appropriately selected depending on the desired application.

[0027] The shape of the potential-generating filament, particularly its cross-sectional shape, is not particularly limited, and it may have, for example, a circular, elliptical, rectangular, and / or irregular cross section. It is preferable that the cross section be circular.

[0028] The electric potential-generating filament of the present disclosure has microvoids MV on its surface (see FIG. 5). In this specification, "microvoids" refers to recesses on the order of microns. From another perspective, microvoids refer to recesses resulting from a damage processing treatment on the electric potential-generating filament in the "manufacturing method" described below. To explain the damage processing in more detail, it refers to processing based on a chemical treatment (solution treatment).

[0029] As described in detail in the "Manufacturing Method" below, the damage processing treatment for the potential-generating filament is preferably an alkali weight loss processing treatment. This processing treatment can appropriately form microvoids on the surface of the potential-generating filament. Therefore, the surface of the potential-generating filament may have an alkaline component based on the alkali weight loss processing treatment.

[0030] According to the electric potential generating filament of the present disclosure, since it has a microvoid MV on its surface, it is possible to generate a strong electric field (V / m) in the microvoid. More specifically, in FIG. 6, the electric field (V / m) generated in the microvoid MV is the value obtained by dividing the surface potential (V) by the void width d (m). The void width d is on the order of microns (10 -6 ) and the surface potential is 0.1 V or more as mentioned above. Therefore, the microvoid MV has a length of 10 5 It is possible to generate a relatively strong electric field of the order of 100 nm or more. Furthermore, without being bound by a particular theory, when bacteria K enter the microvoid MV, the electric field in the microvoid MV acts on the bacteria K, resulting in a sterilizing effect.

[0031] The size of the microvoid is preferably smaller than the diameter of the potential-generating filament. There is no particular limitation on the diameter of the potential-generating filament, and it may or may not be the same (constant) along the length of the potential-generating filament. The potential-generating filament may have a thickness of, for example, 10 μm to 1 mm. The thickness may be appropriately selected depending on the desired application. In this manner, microvoids can be appropriately formed in the potential-generating filament.

[0032] The upper limit of the size of the microvoids may be set to 3 μm. In this embodiment, even in a potential-generating filament with a diameter of about 10 μm, microvoids can be appropriately formed.

[0033] The lower limit of the size of the microvoids may be a size that can accommodate bacteria. Here, the size of the bacteria is a size that can be visually recognized using an optical microscope, and the lower limit may be 0.5 μm. In this embodiment, the bacteria can be appropriately introduced into the microvoids, and the electric field in the microvoids can act on the bacteria to provide a sterilizing effect.

[0034] In this specification, the "size of the microvoid" refers to the size in the radial direction of the potential-generating filament (void width d). In other words, the "length of the microvoid" (in other words, the length in the direction perpendicular to the radial direction, the length in the axial direction, or the length of the void in the direction perpendicular to the paper surface in FIG. 6) is not limited to the above numerical range, and may extend in the axial direction by about 1 mm.

[0035] Microvoids include 10 5 V / m or more 10 7 It is preferable that an electric field strength of 1000 V / m or less is generated. In such an embodiment, the electric field in the microvoids acts on bacteria, and a sterilizing effect can be achieved.

[0036] [Regarding the first embodiment of the yarn of the present disclosure (S yarn)] The yarn of the present disclosure may be a yarn obtained by simply aligning a plurality of potential-generating filaments having microvoids (aligned yarn or non-twisted yarn), a twisted yarn (twisted yarn or twisted yarn), a crimped yarn (crimped yarn or false twisted yarn), or a spun yarn (spun yarn).The potential-generating filament may have a configuration in which a conductor is used as a core yarn, the conductor is wrapped (covered) with an insulator, and a voltage is applied to the conductor to generate an electric charge.

[0037] The fiber strength of the yarn of the present disclosure is preferably 1 to 10 cN / dtex. This allows the yarn of the present disclosure to withstand large deformation caused by the generation of a high electric 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 yarn of the present disclosure is preferably 10 to 50%.

[0038] As shown in FIG. 1(A), the thread 1s may be constructed by twisting together a plurality of potential-generating filaments 10. In the embodiment shown in FIG. 1(A), the thread 1s is a left-handed twisted thread (hereinafter referred to as an "S thread") in which the potential-generating filaments 10 are twisted to the left, but it may also be a right-handed twisted thread (hereinafter referred to as a "Z thread") in which the potential-generating filaments 10 are twisted to the right (see, for example, thread 1z in FIG. 3(A)). Thus, in the case of a twisted thread, the thread may be either an "S thread" or a "Z thread". Note that microvoids are not shown in FIG. 1.

[0039] In the yarn, the interval between the potential-generating filaments 10 is about 0 μm to about 10 μm, and generally about 5 μm. When the interval between the potential-generating filaments 10 is 0 μm, this means that the potential-generating filaments are in contact with each other.

[0040] In order to describe the yarn in detail, a detailed description will be given below of an embodiment in which the electric potential generating filament 10 contains a piezoelectric material, and the piezoelectric material is "polylactic acid," as an example.

[0041] As shown in Figure 1(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 potential-generating filament 10 comprising uniaxially stretched polylactic acid has tensor components d14 and d25 as piezoelectric strain constants.

[0042] Therefore, polylactic acid can generate electric charge (or potential) most efficiently when it is distorted in a direction at 45 degrees to the uniaxially stretched direction.

[0043] 2(A) and 2(B) are diagrams showing the relationship between the uniaxial stretching direction of polylactic acid, the direction of electric potential, and the deformation of the fiber including the electric potential-generating filament 10 and / or yarn.

[0044] As shown in FIG. 2(A), when the potential-generating 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 a potential in the direction from the back side to the front side of the paper. That is, the potential-generating filament 10 can generate a negative charge on the front side of the paper. As shown in FIG. 2(B), when the potential-generating 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 a potential can be generated in the direction from the front side of the paper to the back side. That is, the potential-generating filament 10 can generate a positive charge on the front side of the paper.

[0045] The yarn 1s shown in Fig. 1 is a yarn (multifilament yarn) (S yarn) made by twisting a plurality of potential-generating filaments 10 containing such polylactic acid (there is no particular restriction on the twisting method), in which the stretching direction 900 of each potential-generating filament 10 coincides with the axial direction of each potential-generating filament 10. Therefore, the stretching direction 900 of the potential-generating filament 10 is inclined to the left with respect to the axial direction of the yarn. This angle depends on the number of twists.

[0046] When an "external force", such as tension (preferably axial tension) or stress (preferably axial tensile stress) is applied to such an S-thread, thread 1s, a negative (-) charge (or potential) is generated on the surface of thread 1s, and a positive (+) charge (or potential) can be generated inside it.

[0047] The yarn 1s can form a surface potential due to a potential difference that can be generated by this charge. This surface potential can leak into the nearby space and form a combined potential with other parts. In addition, the surface potential generated on the yarn 1s can also generate a potential between the yarn and an object having a predetermined potential, such as a human body, when the yarn is close to the object.

[0048] In a yarn in which such a surface potential is generated, microvoids are formed in the potential-generating filaments that make up the yarn, as described above, and the electric field in the microvoids can act on bacteria, resulting in a bactericidal effect.

[0049] In addition to having a direct bactericidal or virucidal effect due to the surface potential of the potential-generating filament and / or the electric field in the microvoids, it may also have an effect of inhibiting the growth of bacteria, or it may have an effect of repelling bacteria and viruses by generating an electric potential opposite to the electric potential possessed by bacteria, fungi, and other microorganisms and viruses.

[0050] [Regarding the second embodiment of the yarn of the present disclosure (Z yarn)] In the embodiment shown in FIG. 3(A), the yarn 1z may be a right-handed twisted yarn (hereinafter referred to as "S yarn") in which the potential-generating filament 10 is twisted to the right. Here, since the yarn 1z is a Z yarn, the extension direction 900 of the potential-generating filament (or piezoelectric fiber) 10 may be inclined to the right with respect to the axial direction of the yarn 1z. The angle depends on the number of times the yarn is twisted. The polarities of the charges (or potentials) generated in the yarn 1s and the yarn 1z are different from each other. Microvoids are not shown in FIG. 3.

[0051] When an "external force", such as tension (preferably axial tension) or stress (preferably axial tensile stress) is applied to such a Z-thread, thread 1z, a positive (+) charge (or potential) can be generated on the surface of thread 1z, and a negative (-) charge (or potential) can be generated inside it.

[0052] The yarn 1z can also form a surface potential due to a potential difference that can be generated by this charge. This surface potential can leak into the nearby space and form a combined potential with other parts. In addition, the potential generated in the yarn 1z can also generate a potential between the yarn 1z and an object having a predetermined potential (including ground potential), such as a human body, when the yarn 1z is close to the object.

[0053] Furthermore, as described above, microvoids are formed in the potential-generating filaments that make up the yarn, and the electric field in the microvoids can act on bacteria, resulting in a sterilizing effect.

[0054] The S-thread 1s and the Z-thread 1z can be better understood by reading Japanese Patent No. 6428979. Japanese Patent No. 6428979 is incorporated herein by reference.

[0055] [Regarding the third embodiment of the yarn of the present disclosure (yarn provided with a dielectric)] Furthermore, the yarn may have a "dielectric" provided around the potential-generating filament 10. For example, as shown in the cross-sectional view of Fig. 4, a dielectric 100 may be provided around the potential-generating filament 10. Note that microvoids are not shown in Fig. 4.

[0056] In this disclosure, the term "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) depending on an electric potential) and is capable of storing electric charges on its surface.

[0057] The dielectric 100 may be present in the longitudinal direction and the circumferential direction of the potential-generating filament 10, and may completely or partially cover the potential-generating filament 10. When the dielectric 100 partially covers the potential-generating filament 10, the potential-generating filament 10 itself may be exposed in the uncovered portion.

[0058] Therefore, the dielectric 100 may be provided over the entire area or part of the area in the longitudinal direction of the potential-generating filament 10. Also, the dielectric 100 may be provided over the entire area or part of the area in the circumferential direction of the potential-generating filament 10.

[0059] Furthermore, the dielectric material 100 may have a uniform or non-uniform thickness (see, for example, FIG. 4).

[0060] The dielectric 100 may be present between a plurality of potential-generating filaments 10. In this case, there may be a portion between the plurality of potential-generating filaments 10 where the dielectric 100 is not present. Also, air bubbles or cavities may be present in the dielectric 100.

[0061] There is no particular limitation on the dielectric 100 as long as it includes a material or substance having dielectric properties. As the dielectric 100, a dielectric material (e.g., oil, antistatic agent, etc.) known to be usable as a surface treatment agent (or fiber treatment agent) mainly in the textile industry may be used.

[0062] In the yarn, the dielectric 100 preferably contains an oil. As the oil, an oil (spinning oil) used as a surface treatment agent (or fiber treatment agent) that can be used in the manufacture of the potential-generating 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 manufacture (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 manufacture process, the finishing process, etc. are given as representative examples, but the present invention is not limited to these processes. As the oil, an oil used to reduce the friction of the potential-generating filament 10 is preferably used.

[0063] Examples of oils include the Delion series manufactured by Takemoto Yushi Co., Ltd., the Marposol series and Marpocise series manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd., and the Paratex series manufactured by Marubishi Yuka Kogyo Co., Ltd.

[0064] The oil may be present entirely or at least partially along the potential-generating filament 10. After the potential-generating filament 10 is processed into yarn, at least a part or all of the oil may fall off from the potential-generating filament 10 by washing.

[0065] Furthermore, the dielectric 100 used to reduce friction of the electric potential generating filament 10 may be a surfactant such as a detergent or fabric softener used in laundry.

[0066] 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.

[0067] 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.

[0068] 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-generating 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 potential-generating filament 10.

[0069] Examples of the antistatic agent include the Capron series manufactured by Nisshin Chemical Laboratory Co., Ltd., the Nicepol series manufactured by Nicca Chemical Co., Ltd., and the Daytron series.

[0070] The antistatic agent may be present entirely or at least partially along the potential-generating filament 10. After the potential-generating filament 10 is processed into yarn, at least a part or all of the antistatic agent may fall off from the potential-generating filament 10 by washing.

[0071] 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 potential-generating filaments 10. In other words, the potential-generating filaments 10 or yarns 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-generating filaments 10 may function as a dielectric. Therefore, in this case, the dielectric comprises air.

[0072] For example, a yarn having a surface treatment agent (or fiber treatment agent) such as the above-mentioned oil agent or antistatic agent, detergent, fabric softener, etc. attached around the potential-generating filament 10 may be treated by washing or immersion in a solvent to use a yarn that does not contain the above-mentioned surface treatment agent (or fiber treatment agent), detergent, fabric softener, etc. In this case, the solid potential-generating filament 10 is exposed. Alternatively, in the present disclosure, a yarn comprising only the solid potential-generating filament 10 may be used.

[0073] In addition, in the present disclosure, a yarn may be used in which 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 processing such as washing or soaking in a solvent, thereby partially exposing the pure potential-generating filaments 10.

[0074] The thickness of the dielectric 100 (or the spacing between the potential generating 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.

[0075] [Other preferred embodiments of the yarn] In the yarn of the present disclosure, the yarn of the first embodiment and the yarn of the second embodiment may be false-twisted. The false-twisted yarn can be made thicker. In addition, the false-twisted yarn can be a bulky crimped yarn. In other words, the false-twisted yarn can be a spun-like yarn that has a spun yarn-like volume and a soft texture due to the presence of loop-shaped fuzz. Furthermore, when the S yarn and the Z yarn are false-twisted, the torques of the left-turned S yarn and the right-turned Z yarn are offset, so that the skew of the knitted fabric can be suppressed in the subsequent dyeing process of the fabric. The false-twisted yarn is not limited to the form of the S yarn and the Z yarn, and may be a form in which S yarns are mutually twisted, or a form in which Z yarns are mutually twisted.

[0076] In the yarn of the present disclosure, the electric potential generating filament is preferably made of polylactic acid (PLA). When the electric potential generating filament contains a piezoelectric material such as polylactic acid, the surface electric 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 impart 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.

[0077] The crystallinity of the "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 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 increased, and polarization due to the piezoelectricity of the 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).

[0078] In addition to polylactic acid-based polymers, the piezoelectric material of the present disclosure may also be, for example, polypeptide-based (e.g., poly(γ-benzyl glutarate), poly(γ-methyl glutarate), etc.), cellulose-based (e.g., cellulose acetate, cyanoethyl cellulose), polybutyric acid-based (e.g., poly(β-hydroxybutyric acid), etc.), polypropylene oxide-based optically active polymers and their derivatives, etc., which may be used as the polymer piezoelectric material.

[0079] In the yarn (electric potential generating filament) of the present disclosure, preferably, additives such as plasticizers and / or lubricants are not included. It is generally known that when additives are included in yarn, it tends to be difficult for a surface potential to be generated. Therefore, in order to appropriately generate a surface potential, it is preferable that the yarn does not contain additives. In this specification, a "plasticizer" is a material that gives flexibility to the yarn, and a "lubricant" is a material that improves the slippage of the piezoelectric yarn molecules. Specifically, polyethylene glycol, castor oil-based fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyethylene glycol fatty acid ester, stearic acid amide and / or glycerin fatty acid ester are intended. These materials are not included in the yarn of the present disclosure.

[0080] The yarn (electric potential generating filament) of the present disclosure may contain a hydrolysis inhibitor. In particular, it may contain a hydrolysis inhibitor for polylactic acid (PLA). As an example of the hydrolysis inhibitor, it may contain a carbodiimide. More preferably, it may contain a cyclic carbodiimide. More specifically, it may be a cyclic carbodiimide described in Japanese Patent No. 5475377. With such a cyclic carbodiimide, the acidic group of the polymer compound can be effectively blocked. In addition, a carboxyl group blocking agent may be used in combination with the cyclic carbodiimide compound to an extent that the acidic group of the polymer can be effectively blocked. Examples of such a carboxyl group blocking agent include agents described in Japanese Patent Publication No. 2005-2174, such as epoxy compounds, oxazoline compounds and / or oxazine compounds.

[0081] The role of the hydrolysis inhibitor will be described 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-generating fibers or potential-generating 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-generating fibers or potential-generating 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.

[0082] The thread of the present disclosure should not be interpreted as being limited to the above-mentioned embodiment, particularly to threads that may be made of polylactic acid. In addition, there is no particular limitation on the manufacturing method of the thread of the present disclosure, and the manufacturing method is not limited to the above-mentioned manufacturing method.

[0083] -Description of the Fabric of the Present Disclosure- The fabric of the present disclosure includes a yarn having microvoids on the surface of an electric potential generating filament that generates an electric potential upon receiving external energy. The fabric of the present disclosure includes woven fabrics, knitted fabrics, and / or nonwoven fabrics. In addition, the term "fabric" in this disclosure is used synonymously with "fabric" although it is intended to mean the material from which clothing is made.

[0084] Here, as an example of a fabric, a knitted fabric formed by knitting the above-mentioned yarn will be specifically described. Here, the term "knitted fabric" as used herein means a structure having a structure in which a plurality of loops are connected to each other, that is, a sheet-like structure having a knit structure. For example, a knitted fabric can be knitted by making a loop of yarn (e.g., a ring-shaped part) and continuously hooking the next loop onto the loop to form a surface or structure. More specifically, the knitted fabric 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 fabrics also include tricot and raschel. In addition, sewn products such as cut-and-sewn and knit-and-sewn are also included in the knitted fabrics of the present disclosure. Furthermore, non-sewn products such as whole garments are also included in the knitted fabrics of the present disclosure (WHOLEGARMENT (registered trademark)).

[0085] Examples of weaves that may be included in the knitted fabric 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 / or milling. The weaves may be different on the front and back of the knitted fabric. Also, the weave may include "tucks". In other words, tuck knitting may be used in combination. The weave may include "misses". The knitted fabric may be reverse pile or reverse brushed. Depending on the weave, the feel, breathability, and / or stretchability of the fabric may be changed.

[0086] In this disclosure, a structure including the minimum repeating units of a "knit", and optionally a "tuck" and / or a "miss" is referred to as a "complete structure".

[0087] Such a structure may be formed by using a knitting machine or by hand knitting. When a knitting machine is used, the type is not particularly limited, and any conventionally known knitting machine can be used without particular limitation.

[0088] In the above description, the fabric of the present disclosure has been described as a knitted fabric, but it may be a textile product such as a woven fabric, a braided fabric, a nonwoven fabric, and / or lace.

[0089] -Description of the manufacturing method of the disclosed yarn- Next, a method for producing a yarn according to the present disclosure will be described. The method for producing a yarn according to the present disclosure includes a step of forming microvoids in an electric potential generating filament that generates an electric potential upon receiving external energy.

[0090] The preparation of the "potential generating filament that generates a potential by receiving energy from the outside" is the same as that described in the conventionally known Patent No. 6428979, so a detailed explanation will be omitted. The process of forming the microvoids will be described below.

[0091] [Process for forming microvoids] An example of a process for forming microvoids is alkali weight loss processing, which is generally known in the textile field to be carried out by treating the surface of a fiber with an alkaline solution in order to improve the texture and / or impart a glossy feel.

[0092] In response to this, the inventors of the present application have applied an alkaline weight reduction treatment based on the purpose of "providing a thread, cloth, and a method for manufacturing the thread with a high antibacterial effect," as opposed to the conventionally known purpose of "improving the texture and / or imparting a glossy feel to the fiber." In other words, the inventors of the present application have discovered that the antibacterial effect is enhanced by applying an "alkaline weight reduction treatment" as a new finding to an "electric potential generating filament capable of generating an electric potential." This finding is a new finding that cannot be derived from a "fiber that does not generate a surface electric potential."

[0093] According to the yarn manufacturing method disclosed herein, microvoids can be appropriately formed by alkaline weight reduction processing, and when bacteria enter the microvoids, the electric field in the microvoids acts on the bacteria, resulting in a bactericidal effect.

[0094] For the alkaline weight reduction treatment, the treatment liquid is preferably NaOH or NaHCO3. Such a treatment liquid can appropriately form microvoids in the potential generating filament. In addition, the concentration of the treatment liquid is preferably a concentration at which microvoids can be formed. As an example, the concentration of NaOH is preferably 3 g / L or more.

[0095] The processing conditions for the alkali weight loss treatment are preferably such that the weight loss rate is 10% or more. However, the weight loss rate is not limited to this, and the weight loss rate may be less than 10% as long as microvoids can be appropriately formed.

[0096] The processing time and temperature of the alkali weight reduction processing may be appropriately set so that microvoids can be appropriately formed. As an example, the processing temperature of the NaOH solution may be set to 50°C or higher, and the processing time may be set to 20 minutes or more. However, the processing conditions are not limited to the above, and the processing temperature may be set to less than 50°C and the processing time may be set to less than 20 minutes as long as microvoids can be appropriately formed.

[0097] [Additional process (process to promote the formation of microvoids)] In a preferred embodiment of the method for producing yarn according to the present disclosure, the method may further include a step of promoting the formation of microvoids in the electric potential-generating filament.

[0098] In this specification, the "step of promoting the formation of microvoids" refers to a physical treatment of the potential-generating filament, and an example of this is buffing. Note that buffing refers to rubbing the cloth provided with the potential-generating filament.

[0099] There are no particular limitations on the method and equipment used for buffing (also called buffing or sanding), but the condition of the fabric and yarn surface can be adjusted by factors such as the roughness of the buff, the number of rotations of the roller (pile roller (PR) or counter pile roller (CPR)), the number of rotations of the fabric, the brake value, and the number of times the process is applied.

[0100] As described above, by undergoing the "step of promoting the formation of microvoids" of the present disclosure, microvoids can be more appropriately formed in the potential-generating filament. EXAMPLES

[0101] Fabrics containing the yarns of the present disclosure were evaluated for microvoids and antibacterial properties, as described in detail below.

[0102] [Evaluation of microvoids] For the fabrics of Examples 1-1 and 1-2 and Comparative Examples 1-1 and 1-2 shown in Table 1 below, microvoids formed in the potential-generating filaments were confirmed by electron microscope.

[0103] [Table 1]

[0104] In Example 1-1 and Comparative Example 1-1 in Table 1, the fabric was subjected to an alkali weight reduction treatment after dyeing. Note that Example 1-1 and Comparative Example 1-1 use the same yarn, both of which have a total fineness of 84 dtex and 72 filaments, and generate an electric potential when receiving energy from an external source.

[0105] On the other hand, in Example 1-2 and Comparative Example 1-2 in Table 1, the gray fabric before dyeing was subjected to an alkali weight reduction treatment. Note that Example 1-2 and Comparative Example 1-2 use the same yarn, and both have a total fineness of 84 dtex and 24 filaments, and are yarns that generate an electric potential when receiving energy from an external source.

[0106] The "alkaline weight loss processing" performed in Examples 1-1 and 1-2 used a NaOH solution of 3 g / L or more, and adopted processing conditions of a processing temperature of 50°C or more and a processing time of 60 minutes or more, achieving a weight loss rate of 10% or more.

[0107] When the fabrics of Examples 1-1 and 1-2 were observed under an electron microscope, microvoids could be observed as shown in Figure 5. On the other hand, when the fabrics of Comparative Examples 1-1 and 1-2 were observed under an electron microscope, no microvoids could be observed.

[0108] [Antibacterial evaluation] To evaluate the antibacterial properties, fabrics of Examples 2-1 and 2-2 and Comparative Example 2-1 shown in Table 2 below were prepared.

[0109] [Table 2]

[0110] The details of the antibacterial test in this specification are as follows. (1) The viable cell count is measured for the comparative example and example products in their initial state. (2) The products of the comparative example and the example are left to stand for 120 minutes and then the viable cell count is measured. (3) After leaving the comparative example and example products to stand for 30 minutes, the products are stretched and contracted continuously for 90 minutes to generate a surface potential, after which the number of viable bacteria is 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 120 minutes of standing Viable bacteria count B: Viable bacteria count after continuously stretching the product for 90 minutes to generate a surface potential The antibacterial test in this specification is different from the antibacterial tests described in Patent Documents 1 to 3 (observation of the viable cell count after 18 hours) in that it is an antibacterial test conducted in a relatively short period of time. The viable cell count was evaluated based on the method of JIS L1902, as described in Patent Nos. 6922546 and 6292368. The viable cell count value indicates the logarithm of the Colony Forming Unit (logarithm of colonies per gram).

[0111] According to the results in Table 2, the fabrics of Examples 2-1 and 2-2 had better antibacterial activity values ​​than the fabric of Comparative Example 2-1. Furthermore, the fabric of Example 2-2 was subjected to buffing treatment (a process for promoting the formation of microvoids) in addition to the alkali weight reduction treatment, and as a result, the formation of microvoids was promoted, resulting in a higher antibacterial activity value.

[0112] Aspects of the yarn, fabric, and method for producing the yarn of the present disclosure are as follows. <1> A yarn having microvoids on the surface of a potential generating filament that generates a potential upon receiving external energy. <2> The size of the microvoid is smaller than the diameter of the potential generating filament. <1> The yarn described in <3> The upper limit of the size of the microvoids is 3 μm. <1> or <2> The yarn described in <4> The lower limit of the size of the microvoids is a size that can accommodate bacteria. <1> ~ <3> 2. The yarn according to claim 1 . <5> The microvoids include 10 5 V / m or more 10 7 V / m or less. <1> ~ <4> 2. The yarn according to claim 1 . <6> the electric potential generating filament comprises a piezoelectric material; <1> ~ <5> 2. The yarn according to claim 1 . <7> The piezoelectric material comprises polylactic acid. <6> The yarn described in <8> The piezoelectric material does not contain any additives. <6> or <7> The yarn described in <9> The piezoelectric material contains a hydrolysis inhibitor. <6> ~ <8> 2. The yarn according to claim 1 . <10> Generate a surface potential greater than 0.1 V. <1> ~ <9> 2. The yarn according to claim 1 . <11> The potential generating filament has an alkaline component on its surface. <1> ~ <10> 2. The yarn according to claim 1 . <12> <1> ~ <11> A fabric comprising the yarn described in any one of the above. <13> A method for producing yarn, comprising a step of forming microvoids in an electric potential generating filament that generates an electric potential upon receiving external energy. <14> The microvoids are formed by alkali weight reduction processing. <13> A method for producing the yarn described in claim 1. <15> The alkali weight loss process uses NaOH and / or NaHCO3. <14> A method for producing the yarn described in claim 1. <16> The method further includes a step of promoting the formation of the microvoids with respect to the potential generating filament. <13> ~ <15> 13. A method for producing a yarn according to any one of the preceding claims. <17> The step of promoting the formation of microvoids is buffing. <16> A method for producing the yarn described in claim 1.

[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 disclosure is not interpreted solely by the above-described embodiments, but is defined based on the claims. The technical scope of the present disclosure also includes all modifications within the scope and meaning equivalent to the claims. [Industrial Applicability]

[0114] The present disclosure can be utilized, for example, in highly antimicrobial yarns and fabrics. [Explanation of symbols]

[0115] 1s,1z thread 10. Potential generating filament 100 Dielectric 900 Stretching direction 910A 1st diagonal 910B 2nd diagonal MV Microvoid K bacteria d Void width

Claims

1. The filament has microvoids on its surface that generate a potential when it receives energy from an outside source. A yarn in which an electric field strength of 10 5 V / m or more and 10 7 V / m or less is generated in the microvoids.

2. The filament has microvoids on its surface that generate a potential when it receives energy from an outside source. A yarn that generates a surface potential greater than 0.1 V.

3. The yarn according to claim 1 or 2, wherein the size of the microvoids is smaller than the diameter of the electric potential-generating filament.

4. 3. The yarn of claim 1 or 2, wherein the upper limit of the size of the microvoids is 3 μm.

5. The yarn according to claim 1 or 2, wherein the lower limit of the size of the microvoids is a size that can accommodate bacteria.

6. The microvoids include 10 ５ V / m or more 10 ７ 3. The yarn of claim 2, which produces an electric field strength of 0.1 V / m or less.

7. The yarn of claim 1 or 2, wherein the electric potential-generating filaments comprise a piezoelectric material.

8. The yarn of claim 7 , wherein the piezoelectric material comprises polylactic acid.

9. The yarn of claim 8 , wherein the piezoelectric material is additive-free.

10. The yarn of claim 8 , wherein the piezoelectric material contains a hydrolysis inhibitor.

11. 10. The yarn of claim 1, which generates a surface potential of greater than 0.1 V.

12. The yarn according to claim 1 or 2, wherein the electric potential generating filament has an alkaline component on its surface.

13. A fabric comprising the yarn according to claim 1 or 2.

14. The method includes a step of forming microvoids in a potential generating filament that generates a potential upon receiving energy from an outside source, The method for producing a yarn further comprises a step of promoting the formation of the microvoids in the electric potential-generating filament.

15. The method for producing a yarn according to claim 14, wherein the microvoids are formed by an alkaline weight reduction process.

16. The alkali weight loss treatment may include NaOH and / or NaHCO ３ The method for producing a yarn according to claim 14, wherein

17. The method for producing a yarn according to claim 14, wherein the step of promoting the formation of microvoids is buffing.

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