Yarn, cloth, and yarn manufacturing method

Abstract

Provided are a yarn having a high antibacterial effect, a cloth, and a method for manufacturing the yarn. The yarn of the present invention has micro-voids (MV) on the surface of a potential generating filament (10) that generates a potential upon receiving energy from the outside.

Description

Technical Field

[0001] The present invention relates to yarn, cloth and a method for producing the yarn. Background Art

[0002] Conventionally, yarns having fibers that generate surface potentials under the action of external energy have been proposed (see Patent Documents 1 to 3). The yarns described in Patent Documents 1 to 3 can exert antibacterial effects by generating surface potentials specified under predetermined conditions.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2017 / 212836

[0006] Patent Document 2: Japanese Patent Application Publication No. 2018-90950

[0007] Patent Document 3: Japanese Patent Application Publication No. 2019-131948 Summary of the invention

[0008] Problem that the invention aims to solve

[0009] Patent documents 1 to 3 disclose verification tests for observing the number of live bacteria 18 hours after inoculation of test bacteria (bacteria). In view of this, from the perspective of practicality, it is desirable to have a yarn that exerts an antibacterial effect in a shorter period of time. In addition, although the yarns described in patent documents 1 to 3 can generate a specified surface potential (V) under predetermined conditions, there is room for improvement to further enhance the antibacterial effect.

[0010] Therefore, an object of the present invention is to provide a yarn, a cloth and a method for producing the yarn having a high antibacterial effect.

[0011] Solutions for solving problems

[0012] The yarn of the present invention has micro voids on the surface of the potential generating yarn which generates a potential by receiving energy from the outside.

[0013] The cloth of the present invention comprises the above-mentioned yarn.

[0014] The method for producing a yarn of the present invention comprises the step of forming micro voids in a potential generating yarn that generates a potential by receiving energy from the outside.

[0015] Effects of the Invention

[0016] According to the present invention, micro gaps are provided on the surface of the potential generating filament, so that a strong electric field (V / m) can be generated in the micro gaps. Therefore, the strong electric field can be used to effectively exert an antibacterial effect. In addition, the effects described in this specification are at best illustrative and not restrictive, and additional effects may also exist. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 (A) is a diagram showing the structure of a yarn (S yarn), Figure 1 (B) is Figure 1 The cross-sectional view of (A) at line AA, Figure 1 (C) is Figure 1 Cross-sectional view at line BB of (A).

[0018] Figure 2 (A) and Figure 2 (B) is a diagram showing the relationship between the uniaxial stretching direction of polylactic acid, the potential direction, and the deformation of the potential generating yarn.

[0019] Figure 3 (A) is a diagram showing the structure of a yarn (Z yarn), Figure 3 (B) is Figure 3 The cross-sectional view of (A) at line AA, Figure 3 (C) is Figure 3 Cross-sectional view at line BB of (A).

[0020] Figure 4 This is a cross-sectional view schematically showing a cross section of a yarn having a dielectric around a potential generating yarn.

[0021] Figure 5 This is a SEM photograph of the yarn of the present invention.

[0022] Figure 6 This is a schematic cross-sectional view of a potential generating filament having micro gaps. DETAILED DESCRIPTION

[0023] The yarn, cloth and method for manufacturing the yarn of the present invention are described below. Although the description will be made with reference to the accompanying drawings as needed, the contents of the drawings are only schematically and illustratively shown for the purpose of understanding the present invention, and the appearance, dimensional ratio, etc. may be different from the appearance, dimensional ratio, etc. of the real object. In addition, unless otherwise specifically stated, the various numerical ranges mentioned in this specification are intended to include the numerical values ​​of the lower limit and / or upper limit themselves. In other words, if a numerical range such as 1 to 10 is taken as an example, it can be interpreted as a numerical range including the lower limit value "1" and also including the upper limit value "10". In addition, there are also cases where "about" or "about" is attached to various numerical values, and the terms such as "about" and "about" mean that they may include a few percent, such as ±10%, ±5%, ±3%, ±2%, and / or ±1%. Changes.

[0024] -Description of the Yarn of the Invention-

[0025] The yarn of the present invention is described. The yarn has potential generating filaments that generate potential when receiving energy from the outside. There is no particular restriction on the number of potential generating filaments 10, and it is preferred that the yarn of the present invention contains only 1, 2 or more and 1000 or less, preferably 10 or more and 800 or less, and more preferably 20 or more and 600 or less potential generating filaments.

[0026] [For the potential generating wire]

[0027] As described above, "potential generating filaments" basically refer to "fibers (filaments) that can generate electric charges under the action of external energy (for example, tension and / or stress, etc.) to form potential (specifically, surface potential) and / or electric field" (hereinafter, sometimes also referred to as "potential generating fibers", "potential forming filaments", "potential forming fibers", "charge generating fibers" or "charge generating filaments"). As potential generating filaments, for example, the charge generating fibers described in Japanese Patent Gazette No. 6428979 are preferably used.

[0028] As "energy from the outside", for example, the following external forces can be listed: force from the outside (hereinafter sometimes also referred to as "external force"), specifically, force that causes the yarn or potential generating wire to deform or strain and / or force applied in the axial direction of the yarn or potential generating wire, more specifically, tension (for example, axial tension of the yarn or potential generating wire) and / or stress or strain force (tensile stress or tensile strain applied to the yarn or potential generating wire) and / or force applied in the transverse direction of the yarn or potential generating wire.

[0029] In the potential generating yarn, the surface potential generated by the application of external force is, for example, 0.1V or more, preferably 1.0V or more (it is possible to generate either positive or negative potential). If the surface potential is above 0.1V, the proliferation of bacteria can be inhibited in the yarn and / or cloth of the present invention. There is no particular limitation on the method for measuring the surface potential, and it can be measured using, for example, a scanning probe microscope. In addition, it can also have a direct bactericidal and virucidal effect under the action of the surface potential, or it can be an effect brought about by generating a potential opposite to the potential possessed by bacteria, fungi, and other fungi and viruses so that bacteria and viruses do not approach.

[0030] The potential generating filament preferably contains a material having a piezoelectric effect (polarization phenomenon achieved by external force) or piezoelectricity (the property of generating voltage when mechanical strain is applied or conversely generating mechanical strain when voltage is applied) (hereinafter sometimes also referred to as "piezoelectric material" or "piezoelectric body"). Among them, it is particularly preferred to use fibers containing piezoelectric materials (hereinafter sometimes also referred to as "piezoelectric fibers"). Piezoelectric fibers can form potentials through piezoelectricity, so no power source is required and there is no worry about electric shock. In addition, the life of the piezoelectric material contained in the piezoelectric fiber lasts longer than the antibacterial effect achieved by, for example, drugs. In addition, in such piezoelectric fibers, the possibility of causing allergic reactions is also low.

[0031] The “piezoelectric material” can be used without particular limitation as long as it is a material having a piezoelectric effect or piezoelectricity, and may be an inorganic material such as piezoelectric ceramics or an organic material such as a polymer.

[0032] The “piezoelectric material” (or “piezoelectric fiber”) preferably contains a “piezoelectric polymer.” Examples of the “piezoelectric polymer” include a “piezoelectric polymer having pyroelectricity” and a “piezoelectric polymer not having pyroelectricity.”

[0033] In general, a "piezoelectric polymer having thermoelectricity" refers to a piezoelectric material composed of a polymer material that has thermoelectricity and can generate an electric charge (or potential) on its surface simply by applying a temperature change. Examples of such piezoelectric polymers include polyvinylidene fluoride (PVDF). In particular, a material that can generate an electric charge (or potential) on its surface under the action of the heat energy of the human body is preferred.

[0034] In general, "piezoelectric polymers without pyroelectricity" are composed of polymer materials and refer to piezoelectric polymers other than the above-mentioned "piezoelectric polymers with pyroelectricity". Examples of such piezoelectric polymers include polylactic acid (PLA). As polylactic acid, there are known poly-L-lactic acid (PLLA) formed by polymerization of L-isomer monomers, poly-D-lactic acid (PDLA) formed by polymerization of D-isomer monomers, and the like.

[0035] As an example of a piezoelectric material contained in a potential generating filament, "polylactic acid" can be cited. Polylactic acid (PLA), which can be used as a piezoelectric material, is a chiral polymer with a helical structure in the main chain. If polylactic acid is uniaxially stretched to orient the molecules, it can exhibit piezoelectricity. If heat treatment is further applied to increase the crystallinity, the piezoelectric constant becomes higher. The crystallinity can be increased in this way to increase the value of the surface potential.

[0036] The optical purity (enantiomeric excess (ee)) of polylactic acid (PLA) can be calculated by the following mathematical formula: Optical purity (%) = {|amount of L-isomer - amount of D-isomer| / (amount of L-isomer + amount of D-isomer)}×100

[0037] For example, the optical purity of either the D-body or the L-body is 90% by weight or more, preferably 95% by weight or more, more preferably 98% by weight or more and 100% by weight or less, further preferably 99.0% by weight or more and 100% by weight or less, and particularly preferably 99.0% by weight or more and 99.8% by weight or less. The amount of the L-body and the amount of the D-body of the polylactic acid (PLA) can be obtained by, for example, using a method using high performance liquid chromatography (HPLC).

[0038] The number average molecular weight (Mn) of polylactic acid is, for example, 6.2×10 4 The weight average molecular weight (Mw) is, for example, 1.5×10 5 In addition, the molecular weight is not limited to these values.

[0039] Polylactic acid can generate piezoelectricity through molecular orientation processing achieved by stretching, so it does not need to be polarized like other piezoelectric polymers or piezoelectric ceramics such as polyvinylidene fluoride (PVDF). The piezoelectric constant of polylactic acid after uniaxial stretching is about 5pC / N or more and 30pC / N or less, which is a very high piezoelectric constant among polymers. In addition, the piezoelectric constant of polylactic acid does not change over time and is very stable.

[0040] The potential generating filament is preferably a fiber with a circular cross section. The potential generating filament can be manufactured, for example, by the following methods: a method of extruding a piezoelectric polymer to form a fiber; a method of melt spinning a piezoelectric polymer to form a fiber (for example, including the following methods: spinning in which the spinning process and the stretching process are performed separately, a stretching method, a one-step method in which the spinning process and the stretching process are connected, a POY-DTY method in which a false twisting process can also be performed simultaneously, or an ultra-high-speed spinning method for high speed); a method of forming a piezoelectric polymer into a fiber by dry or wet spinning (for example, including the following methods: a phase separation method or a dry-wet spinning method in which a polymer as a raw material is dissolved in a solvent and extruded from a nozzle to form a fiber, a gel spinning method in which the fiber is uniformly formed in a gel state while maintaining a solvent-containing state, or a liquid crystal spinning method in which a liquid crystal solution or a melt is used to form a fiber); or a method of electrostatically spinning a piezoelectric polymer to form a fiber. In addition, the cross-sectional shape of the potential generating filament is not limited to a circle. Cross-sections having, for example, circular, oval, rectangular, and / or irregular shapes are preferred.

[0041] The electric potential generating filament may be a long fiber or a short fiber. The electric potential generating filament preferably has a length (size) of, for example, 0.01 mm or more. The length may be appropriately selected according to the desired use.

[0042] The shape of the potential generating wire, especially the cross-sectional shape, is not particularly limited, and a circular, elliptical, rectangular, and / or irregular cross-sectional shape is preferred, and a circular cross-sectional shape is preferred.

[0043] The potential generating wire of the present invention has micro-voids MV on its surface (refer to Figure 5 ). In this specification, the so-called "micro voids" refer to recesses on the order of micrometers. Micro voids are explained from another point of view. Micro voids refer to recesses caused by the damage processing performed on the potential generating wire in the "manufacturing method" described later. The damage processing is discussed in more detail, which refers to processing based on chemical treatment (solution treatment).

[0044] The damage treatment of the potential generating wire is preferably an alkali reduction treatment, which is discussed in detail in the "manufacturing method" described later. If this treatment is used, micro voids can be properly formed on the surface of the potential generating wire. Therefore, it is preferred that the surface of the potential generating wire has an alkali component based on the alkali reduction treatment.

[0045] According to the potential generating wire of the present invention, since the potential generating wire has micro-voids MV on the surface, a strong electric field (V / m) can be generated in the micro-voids. Figure 6 In the example, the electric field (V / m) generated in the micro-gap MV is the value obtained by dividing the surface potential (V) by the gap width d (m). The gap width d is micrometer-level (10 -6) length, the surface potential is 0.1 V or more as mentioned above, so that a 10 5 Furthermore, although not limited to a specific theory, by allowing bacteria K to enter the micro-voids MV, the electric field in the micro-voids MV can act on the bacteria K and bring about a sterilization effect.

[0046] As for the size of the micro-void, it is preferably smaller than the diameter of the potential generating wire. There is no particular limitation on the diameter of the potential generating wire, and it can be the same (constant) or different along the length direction of the potential generating wire. It is preferred that the potential generating wire has a thickness of, for example, more than 10 μm and less than 1 mm. The thickness can be appropriately selected according to the desired use. If it is in such a form, micro-voids can be properly formed in the potential generating wire.

[0047] The upper limit of the size of the micro-voids is preferably 3 μm. With such a form, the micro-voids can be appropriately formed even in a potential generating filament having a diameter of about 10 μm.

[0048] The lower limit of the size of the microvoids is preferably set to a size that can accommodate bacteria. The size of the bacteria is a size that can be visually identified using an optical microscope, and the lower limit is preferably set to 0.5 μm. If this form is adopted, the bacteria can properly enter the microvoids, and the electric field in the microvoids can act on the bacteria to bring about a sterilization effect.

[0049] In addition, the "micro-gap size" in this specification refers to the size of the potential generating wire in the radial direction (gap width d). In other words, the "micro-gap length" (in other words, the length in the direction orthogonal to the radial direction, the length in the axial direction, or the length in the radial direction) is Figure 6 The length of the gap in the direction perpendicular to the paper surface) is not limited to the above numerical range and can also extend by about 1 mm in the axial direction.

[0050] Preferably, the microvoids are generated 10 5 V / m or more and 10 7 The electric field strength is below V / m. If this is the case, the electric field in the micro-voids can act on the bacteria and bring about a sterilization effect.

[0051] [First Embodiment of the Yarn of the Present Invention (S Yarn)]

[0052] The yarn of the present invention is preferably a yarn formed by simply plying and twisting a plurality of potential generating yarns having micro-voids (plying yarn or untwisted yarn), but may also be a yarn formed by applying twisting (twisting yarn or twisted yarn), a yarn formed by applying crimping (crimped yarn or false twisted yarn), or a yarn formed by weaving (spun yarn). In addition, the potential generating yarn may be a potential generating yarn having the following structure: a conductor is used as a core wire, an insulator is wound (covered) around the conductor, and a voltage is applied to the conductor to generate charge.

[0053] The fiber strength of the yarn of the present invention is preferably 1 cN / dtex or more and 10 cN / dtex or less. Thus, the yarn of the present invention can withstand even greater deformation in order to generate a higher potential without breaking. The fiber strength is more preferably 1 cN / dtex or more and 7 cN / dtex or less, and most preferably 1 cN / dtex or more and 5 cN / dtex or less. Based on the same principle, the elongation of the yarn of the present invention is preferably 10% or more and 50% or less.

[0054] like Figure 1 As shown in (A), the yarn 1s may be formed by twisting a plurality of potential generating yarns 10. Figure 1 In the form shown in (A), the yarn 1s is a left-handed yarn (hereinafter referred to as "S yarn") formed by twisting the potential generating yarn 10 in a left-handed manner, or it can be a right-handed yarn (hereinafter referred to as "Z yarn") formed by twisting the potential generating yarn 10 in a right-handed manner (for example, refer to Figure 3 In this way, when the yarn is a twisted yarn, it can be either "S yarn" or "Z yarn". Figure 1 The illustration of micro voids is omitted.

[0055] In the yarn, the interval between the potential generating filaments 10 is about 0 μm or more and about 10 μm or less, and is generally about 5 μm. When the interval between the potential generating filaments 10 is 0 μm, it means that the potential generating filaments are in contact with each other.

[0056] In order to explain the yarn in detail, the potential generating yarn 10 includes a piezoelectric material, and a configuration in which the piezoelectric material is “polylactic acid” is taken as an example and explained in detail.

[0057] like Figure 1 As shown in (A), for the potential generating wire 10 containing uniaxially stretched polylactic acid, when the thickness direction is defined as the first axis, the stretching direction 900 is defined as the third axis, and the direction orthogonal to both the first axis and the third axis is defined as the second axis, the piezoelectric strain constant has tensor components d14 and d25.

[0058] Therefore, polylactic acid can generate electric charge (or potential) most efficiently when strain is generated in a direction at 45 degrees with respect to the direction of uniaxial stretching.

[0059] Figure 2 (A) and Figure 2 (B) is a diagram showing the relationship between the uniaxial stretching direction of polylactic acid, the potential direction, and the deformation of fibers including the potential generating yarn 10 and / or the yarn.

[0060] like Figure 2 As shown in (A), if the potential generating filament 10 contracts in the direction of the first diagonal line 910A and stretches in the direction of the second diagonal line 910B orthogonal to the first diagonal line 910A, the potential can be generated in the direction from the back side to the front side of the paper. In other words, the potential generating filament 10 can generate negative charges on the front side of the paper. Figure 2 As shown in (B), the potential generating filament 10 can generate electric charge (or electric potential) even when it is extended in the direction of the first diagonal line 910A and contracted in the direction of the second diagonal line 910B, but the polarity is opposite, and the electric potential can be generated in the direction from the surface of the paper toward the back side. That is, the potential generating filament 10 can generate positive electric charge on the surface side of the paper.

[0061] for Figure 1 As for the yarn 1s shown, in the yarn (multifilament yarn) (S yarn) obtained by twisting a plurality of potential generating yarns 10 containing such polylactic acid (there is no particular limitation on the twisting method), the stretching direction 900 of each potential generating yarn 10 is consistent with the axial direction of each potential generating yarn 10. Therefore, the stretching direction 900 of the potential generating yarn 10 is in a state of being inclined to the left relative to the axial direction of the yarn. In addition, the angle depends on the number of twisting times.

[0062] When an "external force" such as tension (preferably axial tension) or stress (preferably axial tensile stress) is applied to such a yarn 1s as an S yarn, a negative (-) charge (or potential) can be generated on the surface of the yarn 1s and a positive (+) charge (or potential) can be generated on the inside.

[0063] The yarn 1s can form a surface potential by utilizing the potential difference generated by the charge. The surface potential can also leak into the nearby space and form a coupled potential with other parts. In addition, when the surface potential generated by the yarn 1s is close to an object having a predetermined potential close to it, such as a predetermined potential (including ground potential) such as a human body, a potential can also be generated between the yarn and the object.

[0064] In the yarn that generates the surface potential in this way, since micro-voids are formed in the potential generating yarns constituting the yarn as described above, the electric field in the micro-voids can act on bacteria to bring about a bactericidal effect.

[0065] In addition, utilizing the surface potential of the potential-generating wire and / or the electric field in the micro-gaps not only has a direct bactericidal and antiviral effect, but can also have the effect of inhibiting bacterial proliferation. It can also be an effect brought about by generating a potential opposite to the potential possessed by bacteria, fungi and other fungi, and viruses, thereby keeping bacteria and viruses away from each other.

[0066] [Second Embodiment of the Yarn of the Present Invention (Z Yarn)]

[0067] exist Figure 3 In the form shown in (A), the yarn 1z is preferably a right-handed yarn (hereinafter referred to as "S yarn") formed by twisting the potential generating yarn 10 to the right. Among them, the yarn 1z is a Z yarn, so the stretching direction 900 of the potential generating yarn (or piezoelectric fiber) 10 is preferably tilted to the right relative to the axial direction of the yarn 1z. In addition, its angle depends on the number of times the yarn is twisted. In addition, the polarities of the charges (or potentials) generated in the yarn 1s and the yarn 1z are different. In addition, in Figure 3 The illustration of micro voids is omitted.

[0068] When an "external force" such as tension (preferably axial tension) or stress (preferably axial tensile stress) is applied to such a yarn 1z serving as a Z yarn, a positive (+) charge (or potential) can be generated on the surface of the yarn 1z and a negative (-) charge (or potential) can be generated on the inside.

[0069] The yarn 1z can also form a surface potential by utilizing the potential difference generated by the charge. The surface potential can also leak into the nearby space and form a coupled potential with other parts. In addition, when the potential generated by the yarn 1z is close to an object having a predetermined potential close to it, such as a predetermined potential (including ground potential) such as a human body, a potential can also be generated between the yarn 1z and the object.

[0070] Furthermore, as described above, micro-voids are formed in the potential generating yarns constituting the yarn, and therefore the electric field in the micro-voids can act on bacteria to bring about a sterilizing effect.

[0071] The yarn 1s as the S yarn and the yarn 1z as the Z yarn can be understood more deeply by reading Japanese Patent No. 6428979. Japanese Patent No. 6428979 is incorporated in this specification by reference.

[0072] [Third Embodiment of the Yarn of the Present Invention (Yarn Provided with Dielectric Material)]

[0073] Furthermore, it is preferred that the yarn has a "dielectric" disposed around the potential generating wire 10. Figure 4 The cross-sectional view schematically shows that the dielectric 100 can be arranged around the potential generating filament 10. Figure 4 The illustration of micro voids is omitted.

[0074] In the present invention, "dielectric" refers to an object containing a material or substance having "dielectricity" (the property of being electrically polarized (or dielectric polarization or electric polarization) to positive or negative under the action of an electric potential) and can store electric charge on its surface.

[0075] The dielectric 100 preferably exists in the longitudinal axis direction and the circumferential direction of the potential generating wire 10, and may completely cover the potential generating wire or partially cover the potential generating wire. In addition, when the dielectric 100 partially covers the potential generating wire 10, it is preferred that the potential generating wire 10 itself is directly exposed in the uncovered portion.

[0076] Therefore, the dielectric 100 may be provided entirely or partially in the longitudinal axis direction of the potential generating filament 10. In addition, the dielectric 100 may be provided entirely or partially in the circumferential direction of the potential generating filament 10.

[0077] In addition, the thickness of the dielectric 100 may be uniform or non-uniform (for example, see Figure 4 ).

[0078] The dielectric 100 may exist between the plurality of potential generating filaments 10. In this case, there may be a portion where the dielectric 100 does not exist between the plurality of potential generating filaments 10. In addition, air bubbles or cavities may exist in the dielectric 100.

[0079] The dielectric 100 is not particularly limited as long as it contains a material or substance having dielectric properties. As the dielectric 100, dielectric materials (such as oils, antistatic agents, etc.) known to be mainly used as surface treatment agents (or fiber treatment agents) in the fiber industry may be used.

[0080] In the yarn, the dielectric 100 preferably contains an oil. As the oil, an oil (yarn oil) that can be used as a surface treatment agent (or fiber treatment agent) used in the manufacture of the potential generating silk 10 (for example, anionic, cationic or nonionic surfactants, etc.) can be used. In addition, an oil that can be used as a surface treatment agent (or fiber treatment agent) used in the process of cloth making (for example, weaving, weaving, etc.) (for example, anionic, cationic or nonionic surfactants, etc.) or an oil that can be used as a surface treatment agent (or fiber treatment agent) used in the finishing process (for example, anionic, cationic or nonionic surfactants, etc.) can also be used. Among them, as representative examples, silk manufacturing processes, cloth making processes, finishing processes, etc. are listed, but are not limited to these processes. As an oil, it is particularly preferred to use an oil used to reduce the friction of the potential generating silk 10.

[0081] Examples of the oil include the DELION series manufactured by Takemoto Oil & Fats Co., Ltd., the MARPOZOL series and the MARPOZIES series manufactured by Matsumoto Oil & Fats Pharmaceutical Co., Ltd., and the PARATEX series manufactured by Maruhiya Oil Chemical Industry Co., Ltd.

[0082] The oil agent may be present along the entire potential generating yarn 10 or may be present in at least a portion thereof. In addition, after the potential generating yarn 10 is processed into yarn, at least a portion or all of the oil agent may be removed from the potential generating yarn 10 by washing.

[0083] Furthermore, the dielectric 100 used to reduce the friction of the potential generating wire 10 may be a surfactant such as a detergent or a softener used in washing.

[0084] Examples of detergents include ATTACK (registered trademark) series manufactured by Kao Corporation, TOP (registered trademark) series manufactured by Lion Corporation, and ARIEL (registered trademark) series manufactured by Procter & Gamble Japan Ltd.

[0085] Examples of the softener include HUMMING (registered trademark) series manufactured by Kao Corporation, SOFLAN (registered trademark) series manufactured by Lion Corporation, and LENOR (registered trademark) series manufactured by Procter & Gamble Japan Ltd.

[0086] The dielectric 100 preferably has conductivity (property of conducting electricity), and in this case, the dielectric 100 preferably contains an antistatic agent. As the antistatic agent, an antistatic agent that can be used as a surface treatment agent (or fiber treatment agent) used in the manufacture of the potential generating yarn 10 can be used. As the antistatic agent, an antistatic agent used to reduce the looseness of the potential generating yarn 10 is particularly preferably used.

[0087] Examples of the antistatic agent include CRPRON series manufactured by Nissin Chemical Laboratories, Inc., NICEPOLE series manufactured by Nikka Chemical Co., Ltd., and DEATRON series.

[0088] The antistatic agent may be present along the entire potential generating yarn 10 or may be present in at least a portion thereof. In addition, after the potential generating yarn 10 is processed into yarn, at least a portion or all of the antistatic agent may be removed from the potential generating yarn 10 by washing.

[0089] In addition, the above-mentioned surface treatment agents (or fiber treatment agents) such as oils and antistatic agents, detergents, softeners, etc. may not exist around the potential generating yarn 10. That is, there is a case where the potential generating yarn 10 or yarn does not contain the above-mentioned surface treatment agents (or fiber treatment agents) such as oils and antistatic agents, detergents, softeners, etc. In this case, the air (or air layer) existing between the potential generating yarns 10 can function as a dielectric. Therefore, in this case, the dielectric contains air.

[0090] For example, a yarn that does not contain the above-mentioned surface treatment agent (or fiber treatment agent), detergent, softener, etc., may be treated by washing or solvent immersion to attach the above-mentioned surface treatment agent (or fiber treatment agent), detergent, softener, etc. to the potential generating yarn 10. In this case, the clean potential generating yarn 10 is exposed. Alternatively, in the present invention, a yarn consisting only of the clean potential generating yarn 10 may be used.

[0091] In addition, in the present invention, it is also possible to use yarn in which the above-mentioned surface treatment agents such as oils, antistatic agents (or fiber treatment agents), detergents, softeners, etc. are partially removed through treatments such as washing and solvent immersion, and the clean potential generating yarn 10 is partially exposed.

[0092] The thickness of the dielectric 100 (or the interval 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.

[0093] [Other Preferred Embodiments of Yarn]

[0094] In the yarn of the present invention, the yarn of the first embodiment and the yarn of the second embodiment can also be false-twisted and paralleled. By false-twisting and paralleling them, the wire diameter can be thickened. In addition, if it is false-twisted and paralleled, a curled yarn with bulkiness can be obtained. In other words, if it is false-twisted and paralleled, a quasi-spun yarn (Japanese: sponl i kya n) that is given a spun yarn-like expansion and soft texture due to the presence of annular fluff can be obtained. Moreover, when the S yarn and the Z yarn are false-twisted and paralleled, the torques of the left-handed S yarn and the right-handed Z yarn cancel each other out, so the skewness of the knitted fabric can also be suppressed in the subsequent dyeing process of the cloth. In addition, false-twisted and paralleled are not limited to the form achieved by the S yarn and the Z yarn, and can also be set to a form in which the S yarns are paralleled with each other and a form in which the Z yarns are paralleled with each other.

[0095] In the yarn of the present invention, the potential generating yarn is preferably composed of polylactic acid (PLA). The surface potential can be more appropriately controlled by making the potential generating yarn contain a piezoelectric material such as polylactic acid. In addition, polylactic acid is hydrophobic, so it can provide a smooth skin touch, thereby also giving comfort to the knitted fabric structure. In addition, polylactic acid is known as a biodegradable plastic, so it can eventually decompose into CO2 and water, which can reduce the burden on the environment.

[0096] The crystallinity of "polylactic acid" is, for example, 20% or more, preferably 30% or more, more preferably 40% or more, further preferably 50% or more, and particularly preferably 55% or more. The crystallinity can be determined, for example, by measurement methods such as differential scanning calorimetry (DSC), X-ray diffraction (XRD), and wide-angle X-ray diffraction (WAXD). If it is within such a range, the piezoelectricity derived from the polylactic acid crystals becomes higher, and the polarization achieved by the piezoelectricity of the polylactic acid can be more effectively generated. In addition, the following insight was obtained in the present invention that the measured value of the crystallinity measured using WAXD is different from the measured value of the crystallinity measured using DSC by about 1.5 times (DSC measured value / WAXD measured value≈1.5).

[0097] The piezoelectric material of the present invention may also use, in addition to polylactic acid-based polymers, optically active polymers and their derivatives such as polypeptide-based polymers (e.g., poly(γ-benzyl glutarate), poly(γ-methyl glutarate)), cellulose-based polymers (e.g., cellulose acetate, cyanoethyl cellulose), polybutyric acid-based polymers (e.g., poly(β-hydroxybutyric acid)), polypropylene oxide-based polymers, and the like as polymer piezoelectrics.

[0098] In the yarn (potential generating yarn) of the present invention, it is preferred that additives such as plasticizers and / or lubricants are not added. It is generally known that there is a tendency that if additives are contained in the yarn, it is difficult to generate surface potential. Therefore, in order to properly generate surface potential, it is preferred that no additives are contained in the yarn. The so-called "plasticizer" in this specification refers to a material used to impart flexibility to the yarn, and the "lubricant" refers to a material that improves the sliding of the molecules of the piezoelectric yarn. Specifically, it is intended to represent polyethylene glycol, castor oil-based fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyethylene glycol fatty acid esters, stearic acid amide and / or glycerol fatty acid esters, etc. These materials are not contained in the yarn of the present invention.

[0099] The yarn (potential generating yarn) of the present invention preferably contains an anti-hydrolysis agent. In particular, it is preferred to contain an anti-hydrolysis agent for polylactic acid (PLA). As an example of an anti-hydrolysis agent, it is preferred to contain carbodiimide. It is more preferred to contain a cyclic carbodiimide. More specifically, it can also be set to the cyclic carbodiimide described in Japanese Patent No. 5475377. According to such a cyclic carbodiimide, the acidic group of the polymer compound can be effectively blocked. In addition, a carboxyl blocking agent can also be used at the same time as the cyclic carbodiimide compound to the extent that the acidic group of the polymer can be effectively blocked. As the carboxyl blocking agent, the reagents described in Japanese Patent Gazette No. 2005-2174 can be exemplified, such as epoxy compounds, oxazoline compounds and / or oxazine compounds.

[0100] The following describes the effect of the anti-hydrolysis agent. In the past, the generally known fibers or threads containing PLA (fibers or threads that do not generate surface potential) will generate acid due to the hydrolysis of PLA, and the acid will act on bacteria to achieve an antibacterial effect. Therefore, if PLA is hydrolyzed, the fiber or thread will deteriorate. However, the antibacterial mechanism of the potential-generating fiber or potential-generating thread of the present invention is different from that of the past. As described above, the antibacterial effect is achieved by generating a surface potential, so there is no need to generate hydrolysis. Moreover, the potential-generating fiber or potential-generating thread of the present invention contains an anti-hydrolysis agent, so it can prevent hydrolysis in the fiber or thread and inhibit the deterioration of the fiber or thread.

[0101] The yarn of the present invention should not be construed as being limited to the above-mentioned form, especially the yarn made of polylactic acid. In addition, the method for producing the yarn of the present invention is not particularly limited, and is not limited to the above-mentioned production method.

[0102] -Description of the cloth of the present invention-

[0103] The fabric of the present invention contains yarns, and the yarns have microvoids on the surface of the potential generating filaments that generate electric potential when receiving energy from the outside. The fabric of the present invention includes woven fabrics, knitted fabrics, and / or non-woven fabrics, etc. In addition, in the present invention, the term "gray fabric" is used in the sense of being a raw material for making clothes, but is used synonymously with "fabric".

[0104] Among them, as an example of the fabric, a knitted fabric formed by knitting the above-mentioned yarns will be specifically described. Among them, what is called "knitted fabric" in this specification means a structure having a structure in which a plurality of coils are interconnected, that is, a sheet-like structure having a knitting (Japanese: ニット) structure. For example, by making the coils of the yarn (for example, the looped part) and continuously hooking the next coil to this coil, a surface or texture can be formed, and thus the knitted fabric can be knitted. More specifically, it is preferable that the knitted fabric has a texture that can be formed by knitting methods such as weft knitting, warp knitting, circular knitting, tubular knitting, or sock knitting. Such knitted fabrics also include tricot warp knitted fabrics, raschel warp knitted fabrics, etc. In addition, sewn products such as cut and sewn products and knitted sewn products are also included in the knitted fabrics of the present invention. Also, seamless products such as WHOLEGARMENT are also included in the knitted fabrics of the present invention (WHOLEGARMENT (registered trademark)).

[0105] As the textures that the knitted fabric of the present invention may include, for example, plain stitch texture (also known as plain knitting texture (Japanese: 平編み), knitting (Japanese: メリヤス) texture), elastic plain stitch texture, laid-in plain stitch texture, interlock texture (also known as double rib texture), osage stitch texture (front osage stitch texture, back osage stitch texture), knitting float texture (also known as float pattern), honeycomb texture, cross texture (also known as waffle), and / or circular rib (Japanese: フライス) texture, etc. can be cited, but are not limited to these. It is preferable that the textures are different on the front and back of the knitted fabric. In addition, "tuck stitch" may be included in the texture. That is to say, tuck stitch texture may also be used simultaneously. It is preferable that "float" is included in the texture. The knitted fabric can be either terry-lined or fleece-lined. The skin feel, breathability, and / or stretchability of the fabric can be changed depending on the texture.

[0106] In the present invention, the texture that is the smallest repeating unit including "knitting", (optionally) "tuck stitch", and / or "float" is called "complete texture".

[0107] Such a texture can be formed either by using a knitting machine or by hand knitting. In the case of using a knitting machine, there is no particular limitation on its type, and conventionally known knitting machines can be used without particular limitation.

[0108] Furthermore, in the above description, the fabric of the present invention is described as a knitted fabric, but may be a fiber product such as a woven fabric, a knitted fabric, a nonwoven fabric, and / or a braid.

[0109] -Description of the method for producing the yarn of the present invention-

[0110] Next, the method for producing the yarn of the present invention is described. The method for producing the yarn of the present invention includes a step of forming microvoids in a potential generating yarn that generates a potential by receiving energy from the outside.

[0111] The preparation of the "potential generating wire that generates a potential by receiving energy from the outside" is the same as that in the conventionally known Japanese Patent No. 6428979, and thus the description thereof is omitted. The process of forming micro-voids will be described in detail below.

[0112] [Process of forming micro voids]

[0113] An example of a process for forming microvoids is alkali weight reduction treatment. In the field of fibers, alkali weight reduction treatment is generally known to be performed for the purpose of improving the texture and / or glossiness of fibers by treating the surface of the fibers with an alkaline solution.

[0114] In contrast, unlike the previously known purpose of "improving the texture and / or glossiness of the fiber", the inventors of the present application implemented alkali weight reduction treatment based on the purpose of "providing yarn, cloth and yarn manufacturing method with high antibacterial effect". In other words, as a new insight into "potential generating yarn capable of generating potential", the inventors of the present application discovered that the antibacterial effect can be improved by implementing "alkali weight reduction treatment". This insight is a new insight that cannot be derived from "fibers that do not generate surface potential".

[0115] According to the yarn manufacturing method of the present invention, micro voids can be appropriately formed by alkali weight reduction, so that bacteria can enter the micro voids and the electric field in the micro voids can act on the bacteria, thereby achieving a bactericidal effect.

[0116] For the alkali weight reduction treatment, the treatment liquid is preferably NaOH or NaHCO3. If such a treatment liquid is used, microvoids can be properly formed relative to the potential generating wire. In addition, the concentration of the treatment liquid is preferably set to a concentration that can form microvoids. As an example, the concentration of NaOH is preferably 3g / L or more.

[0117] As the treatment conditions of the alkali weight reduction treatment, it is preferable to perform the treatment so that the weight reduction rate becomes 10% or more. However, it is not limited to this weight reduction rate, and the weight reduction rate may be less than 10% as long as microvoids can be formed appropriately.

[0118] The treatment time and treatment temperature for alkali weight reduction treatment are preferably appropriately set in such a manner that microvoids can be properly formed. As an example, it is preferable to set the treatment temperature of the NaOH solution to 50°C or higher and the treatment time to 20 minutes or longer. However, it is not limited to the above treatment conditions, and as long as microvoids can be properly formed, the treatment temperature can be set to less than 50°C and the treatment time can be set to less than 20 minutes.

[0119] [For additional processes (processes for promoting the formation of microvoids)]

[0120] As a preferable form of the method for manufacturing the yarn of the present invention, it is preferable to further include a process for promoting the formation of microvoids in the potential generating filaments.

[0121] In the present specification, the so-called "process for promoting the formation of microvoids" refers to performing a physical treatment on the potential generating filaments. As an example, it refers to polishing treatment. In addition, polishing treatment refers to performing friction treatment on the cloth having potential generating filaments.

[0122] The method and equipment used for polishing treatment (also referred to as polishing wheel treatment, grinding treatment) are not particularly limited, and the surface states of the cloth and the yarn can be adjusted according to factors such as the roughness of the polishing wheel, the rotation speeds of the rollers (progressive roller (PR), counter-progressive roller (CPR)), the rotation speed of the cloth, the braking value, and the number of times of performing the treatment.

[0123] As described above, by undergoing the "process for promoting the formation of microvoids" of the present invention, microvoids can be more appropriately formed in the potential generating filaments.

[0124] Examples

[0125] The evaluation of microvoids and the evaluation of antibacterial properties were performed on the cloth containing the yarn of the present invention. This will be discussed in detail below.

[0126] [Evaluation of microvoids]

[0127] For the cloths of Examples 1-1 to 1-2 and Comparative Examples 1-1 to 1-2 shown in Table 1 below, the microvoids formed in the potential generating filaments were confirmed using an electron microscope.

[0128] [Table 1]

[0129] Example 1-1 Example 1-2 Comparative Example 1-1 Comparative Example 1-2 Total fineness 84dtex 84dtex 84dtex 84dtex Number of wires 72 roots 24 72 roots 24 state Dyeing gray cloth Natural fabric Dyeing gray cloth Natural fabric Alkali weight reduction treatment have have none none The presence or absence of micro voids have have none none

[0130] In Examples 1-1 and Comparative Example 1-1 in Table 1, the cloths were subjected to alkali weight reduction treatment in the dyed state. In addition, the same yarns were used in Examples 1-1 and Comparative Example 1-1, and they were yarns with a total fineness of 84 dtex, 72 filaments, and capable of generating an electric potential when receiving external energy.

[0131] On the other hand, Examples 1-2 and Comparative Examples 1-2 in Table 1 were subjected to alkali weight reduction processing in the state of natural cloth before dyeing. In addition, the yarns used in Examples 1-2 and Comparative Examples 1-2 were the same, with a total fineness of 84 dtex, a number of filaments of 24, and a potential generated by receiving energy from the outside.

[0132] The "alkali weight reduction treatment" performed in Examples 1-1 and 1-2 uses a 3 g / L or higher NaOH solution, a treatment temperature of 50° C. or higher, a treatment time of 60 minutes or higher, and a weight reduction rate of 10% or higher.

[0133] When the fabrics of Example 1-1 and Example 1-2 were observed using an electron microscope, it was observed that Figure 5 On the other hand, when the cloths of Comparative Examples 1-1 and 1-2 were observed with an electron microscope, no microvoids were observed.

[0134] [Antibacterial evaluation]

[0135] In order to evaluate the antibacterial property, cloths of Examples 2-1 to 2-2 and Comparative Example 2-1 shown in Table 2 below were produced.

[0136] [Table 2]

[0137]

[0138] In addition, the contents of the antibacterial test in this specification are as follows.

[0139] (1) The viable cell count of the products of the comparative examples and the examples in the initial state was measured.

[0140] (2) The viable bacterial counts of the products of the comparative examples and the examples were measured after being left to stand for 120 minutes.

[0141] (3) The products of the comparative examples and the examples were left to stand for 30 minutes, and the number of viable cells was measured after the products were continuously expanded and contracted for 90 minutes to generate surface potential.

[0142] That is, the "antimicrobial activity value" of the present invention refers to a value calculated as follows.

[0143] Antibacterial activity value = number of viable bacteria A - number of viable bacteria B

[0144] Viable bacteria count A: Viable bacteria count after 120 minutes of standing

[0145] Number of viable bacteria B: The number of viable bacteria after the product is stretched and contracted continuously for 90 minutes to generate surface potential

[0146] Furthermore, the antibacterial test of the present specification is different from the antibacterial test described in Patent Documents 1 to 3 (observation of the number of viable bacteria after 18 hours) and is an antibacterial test of a relatively short time.

[0147] The viable cell count was evaluated according to the method of JIS L1902 as described in Japanese Patent Nos. 6922546 and 6292368. The viable cell count value represents the logarithmic value of the colony forming unit (Colony Forming Unit) (logarithmic value per 1g of colony).

[0148] According to the results in Table 2, the cloths of Examples 2-1 and 2-2 obtained good results in terms of antimicrobial activity values ​​compared to the cloth of Comparative Example 2-1. Furthermore, the cloth of Example 2-2 was subjected to a polishing process (a process for promoting the formation of microvoids) in addition to the alkali weight reduction process, thereby promoting the formation of microvoids and, as a result, obtaining a higher antimicrobial activity value.

[0149] The yarn, cloth, and method for producing the yarn of the present invention are as follows.

[0150] <1> A yarn having microvoids on a surface of a potential generating yarn that generates a potential by receiving energy from the outside.

[0151] <2> The yarn according to <1>, wherein a size of the micro-voids is smaller than a diameter of the potential generating filaments.

[0152] <3> The yarn according to <1> or <2>, wherein the upper limit of the size of the microvoids is 3 μm.

[0153] <4> The yarn according to any one of <1> to <3>, wherein a lower limit of the size of the microvoids is a size that can accommodate bacteria.

[0154] <5> The yarn according to any one of <1> to <4>, wherein 10 5 V / m or more and 10 7 Electric field strength below V / m.

[0155] <6> The yarn according to any one of <1> to <5>, wherein the potential generating yarn contains a piezoelectric material.

[0156] <7> The yarn according to <6>, wherein the piezoelectric material contains polylactic acid.

[0157] <8> The yarn according to <6> or <7>, wherein the piezoelectric material does not contain an additive.

[0158] <9> The yarn according to any one of <6> to <8>, wherein the piezoelectric material contains an anti-hydrolysis agent.

[0159] <10> The yarn according to any one of <1> to <9>, wherein the yarn generates a surface potential greater than 0.1 V.

[0160] <11> The yarn according to any one of <1> to <10>, wherein an alkaline component is present on a surface of the potential generating yarn.

[0161] <12> A cloth comprising the yarn according to any one of <1> to <11>.

[0162] <13> A method for producing a yarn, comprising the step of forming micro voids in a potential generating yarn that generates a potential by receiving energy from the outside.

[0163] <14> The method for producing a yarn according to <13>, wherein the microvoids are formed by alkali weight reduction.

[0164] <15> The method for producing a yarn according to <14>, wherein NaOH and / or NaHCO 3 is used in the alkali weight reduction process.

[0165] <16> The method for producing a yarn according to any one of <13> to <15>, further comprising the step of promoting formation of the micro-voids in the potential generating yarn.

[0166] <17> The method for producing a yarn according to <16>, wherein the step of promoting the formation of the microvoids is a polishing process.

[0167] In addition, the embodiments disclosed this time are illustrative in all aspects and are not the basis for restrictive interpretation. Therefore, the protection scope of the present invention is not interpreted only by the above-mentioned embodiments, but is defined based on the records of the claims. In addition, the protection scope of the present invention may include all changes within the meaning and scope equivalent to the claims.

[0168] Industrial Applicability

[0169] The present invention can be used, for example, for yarn and cloth having a high antibacterial effect.

[0170] Description of Reference Numerals

[0171] 1s, 1z, yarn; 10, potential generating wire; 100, dielectric; 900, stretching direction; 910A, 1st diagonal; 910B, 2nd diagonal; MV, microgap; K, bacteria; d, gap width.

Claims

1. A yarn, wherein: This yarn has micro voids on the surface of a potential generating yarn that generates a potential by receiving energy from the outside.

2. The yarn according to claim 1, wherein The size of the micro gap is smaller than the diameter of the potential generating wire.

3. The yarn according to claim 1 or 2, wherein: The upper limit of the size of the micro voids is 3 μm.

4. The yarn according to any one of claims 1 to 3, wherein The lower limit of the size of the microvoids is a size that can accommodate bacteria.

5. The yarn according to any one of claims 1 to 4, wherein In the micro voids, 10 5 V / m or more and 10 7 Electric field strength below V / m.

6. The yarn according to any one of claims 1 to 5, wherein The potential generating wire contains a piezoelectric material.

7. The yarn according to claim 6, wherein The piezoelectric material contains polylactic acid.

8. The yarn according to claim 6 or 7, wherein: The piezoelectric material contains no additives.

9. The yarn according to any one of claims 6 to 8, wherein The piezoelectric material contains an anti-hydrolysis agent.

10. The yarn according to any one of claims 1 to 9, wherein The yarn generates a surface potential greater than 0.1V.

11. The yarn according to any one of claims 1 to 10, wherein The potential generating wire has an alkaline component on its surface.

12. A cloth, wherein This cloth comprises the yarn according to any one of claims 1 to 11.

13. A method for producing yarn, wherein: This yarn production method includes a step of forming micro voids in a potential generating yarn that generates a potential by receiving energy from the outside.

14. The method for producing a yarn according to claim 13, wherein: The micro voids are formed by alkali weight reduction processing.

15. The method for producing a yarn according to claim 14, wherein: NaOH and / or NaHCO3 are used in the alkali reduction process.

16. The method for producing a yarn according to any one of claims 13 to 15, wherein: The yarn production method further includes a step of promoting formation of the micro-voids in the potential generating yarn.

17. The method for producing a yarn according to claim 16, wherein: The process that promotes the formation of the micro voids is polishing.

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