Antimicrobial polyester fiber

Abstract

To maintain antibacterial properties after washing in the case of a blended yarn with a fiber having no antibacterial properties.SOLUTION: The antibacterial polyester fiber contains zinc oxide fine particles and simultaneously satisfies the following requirements (A) to (C): (A) the particle size of the zinc oxide fine particles is 10-2000 nm and the content of the zinc oxide fine particles is 2-20 wt% based on the weight of the fiber (B) the product of the average concentration of the zinc oxide fine particles on the fiber surface and the fiber surface area per 1g of fiber is 1.0-3.0 wt%·m2 / g (C) the antibacterial activity value defined by JISL1902 after 50 times of industrial washing is 5.0 or more SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an antibacterial polyester fiber, and more particularly to an antibacterial polyester fiber containing zinc oxide fine particles. [Background technology]

[0002] Synthetic fibers have a variety of excellent properties, including mechanical properties, and are therefore widely used in a variety of fields, including general clothing, interior design, and industrial materials. Adding various functional agents is known as a method for imparting functionality to synthetic fibers, and zinc oxide is known as a functional agent with ultraviolet screening and antibacterial properties.

[0003] As a fiber containing a functional agent, a polyester fiber containing fine particles of zinc oxide and titanium oxide and imparting antibacterial properties by utilizing their photoactive sites is known (Patent Document 1). However, in the polyester fiber described above, the fine inorganic particles tend to aggregate, which not only leads to process defects due to thread breakage during spinning, but also has the drawback of causing polymer degradation during resin molding and resin degradation due to photoactivity when exposed to ultraviolet light.

[0004] Furthermore, as a method for suppressing the aggregation of zinc oxide and preventing bleed-out during spinning, polyamide fibers using a plasticizer when adding zinc oxide have been proposed (Patent Document 2). However, although the method of using a plasticizer can be used for highly hydrophilic polymer compositions such as polyamide, when used with highly hydrophobic polyesters, the excellent mechanical properties, heat resistance, and chemical resistance of polyesters are significantly impaired.

[0005] Furthermore, in order to improve the dispersibility of zinc oxide in yarn, it has been proposed to subject zinc oxide to a surface coating treatment with a specific substance (Patent Documents 3, 4, and 5). However, this has been insufficient in terms of imparting antibacterial activity to fibers, and there have been problems in that when combined with other agents that do not have antibacterial properties, the antibacterial properties, including washing durability, are significantly reduced. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-84758 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-339163 [Patent Document 3] Japanese Patent Application Laid-Open No. 2011-111704 [Patent Document 4] Japanese Patent Publication No. 2020-117827 [Patent Document 5] Japanese Patent Application Publication No. 2022-96619 Summary of the Invention [Problem to be solved by the invention]

[0007] The object of the present invention was made against the background of the above-mentioned conventional technology, and is to provide an antibacterial polyester fiber that has high antibacterial activity and a sustained antibacterial effect, and that exhibits high antibacterial activity and a sustained antibacterial effect even when combined with other fibers or textile products that do not have antibacterial activity. [Means for solving the problem]

[0008] The present invention is an antibacterial polyester fiber containing zinc oxide microparticles, characterized in that it simultaneously satisfies the following requirements (A) to (C): (A) The particle diameter of the zinc oxide fine particles is 10 to 2000 nm, and the content of the zinc oxide fine particles is 2 to 20% by weight based on the weight of the fiber. (B) The product of the average concentration of zinc oxide particles on the fiber surface and the fiber surface area per 1 g of fiber is 1.0 to 3.0 wt% m 2 / g (C) After 50 industrial washes, the antibacterial activity value specified in JIS L 1902 is 5.0 or higher. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide an antibacterial polyester fiber that has high antibacterial properties and sustained antibacterial effects, and that exhibits high antibacterial properties and sustained antibacterial effects even when combined with other fibers or textile products that do not have antibacterial properties. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. [Figure 2] FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will now be described in further detail.

[0012] [Zinc oxide fine particles] The zinc oxide fine particles in the present invention are fine particles of zinc oxide. The particle diameter of the zinc oxide fine particles is 10 to 2000 nm, preferably 15 to 1800 nm, and more preferably 20 to 1500 nm. If the particle diameter is less than 10 nm, aggregation of the zinc oxide nanoparticles occurs, resulting in a decrease in spinnability. On the other hand, if the particle diameter exceeds 2000 nm, this leads to thread breakage during spinning and a decrease in fiber strength.

[0013] The particle size in the present invention is a value determined by a measuring device using a laser diffraction / scattering method, and is a value corresponding to 50% sieving in particle size distribution measurement using a laser diffraction particle size distribution measuring device SALD-1000 manufactured by Shimadzu Corporation.

[0014] The content of zinc oxide microparticles in the antibacterial polyester fiber of the present invention is 2 to 20% by weight, preferably 3 to 18% by weight, more preferably 4 to 16% by weight, and particularly preferably 5 to 15% by weight, based on the weight of the fiber. This fiber weight is the weight of the antibacterial polyester containing zinc oxide microparticles. If the content of zinc oxide microparticles is less than 2% by weight, the fiber will not exhibit high or sustained antibacterial properties when combined with other fibers or textile products that do not have antibacterial properties. On the other hand, if the content exceeds 20% by weight, the mechanical strength of the fiber will be significantly reduced, causing thread breakage and fluffing.

[0015] The antibacterial polyester fiber of the present invention has antibacterial and antimicrobial properties in addition to ultraviolet absorption and deodorizing properties. These antibacterial and antibacterial properties are derived from the photocatalytic activity of zinc oxide microparticles. Therefore, when the antibacterial polyester fiber is mixed with other fibers, there is a problem that the other fibers may be deteriorated by the photocatalysis of the zinc oxide microparticles.

[0016] In the present invention, the deterioration of the fiber-constituting polymer in the vicinity of the zinc oxide microparticles due to the photocatalytic effect of the zinc oxide microparticles and the hydrolysis reaction can be minimized by uniformly dispersing the zinc oxide microparticles in the polyester of the antibacterial polyester fiber and by incorporating the zinc oxide microparticles in the polyester at a high concentration.

[0017] When zinc oxide fine particles contain moisture, a significant hydrolysis reaction occurs. To prevent this, the particle size of the zinc oxide fine particles is measured using a fully automatic BET specific surface area measuring device, Macsorb (manufactured by Mountech Co., Ltd.), and the specific surface area S g and the true specific gravity ρ of the zinc oxide fine particles, the following condition preferably holds: [6 / (S g ×ρ)]×0.85≦Particle diameter (μm)≦[6 / (S g ×ρ)] where S g (m 2 / g) is the specific surface area of ​​zinc oxide particles, ρ (g / cm 3) is the true specific gravity of zinc oxide particles. For the true specific gravity ρ of zinc oxide particles, the true specific gravity of zinc oxide, 5.6, is used in the calculation.

[0018] If the particle size of the zinc oxide fine particles falls within the above range, it is possible to completely remove moisture and minimize the hydrolysis reaction of the polymer in the polyester fiber during melting, which is preferable.

[0019] [Zinc oxide fine particle coating] The zinc oxide particles preferably have a surface coating of a compound containing Si element, which allows the zinc oxide particles to be uniformly dispersed in the polyester fiber and prevents deterioration of the polyester fiber due to the photocatalytic effect.

[0020] Examples of compounds containing Si element include silicone oils such as dimethylpolysiloxane, methylhydrogenpolysiloxane, (dimethicone / methicone) copolymer, polyether-modified silicone, and amino-modified silicone, silicone gels such as (dimethicone / vinyldimethicone) crosspolymer, silicone resins such as trimethylsiloxysilicate, silanes such as alkoxysilanes and their polymers and alkylsilanes, sodium silicate, and silica, with silicone resins being preferred.

[0021] By coating with silicone resin, it is possible to suppress the degradation of the polymer in the polyester fiber caused by the zinc oxide microparticles during fiber production, and to maintain the properties of the zinc oxide microparticles both technically and chemically.

[0022] The amount of Si in the coating of such zinc oxide fine particles is preferably 0.01 to 10 wt % based on the total weight of the zinc oxide fine particles. That is, in the present invention, the zinc oxide fine particles preferably contain 0.01 to 10 wt % of elemental Si based on their weight. By containing Si in this range, the photocatalytic activity of the zinc oxide fine particles can be sufficiently suppressed without waste with a small coating amount, while maintaining the UV absorption and antibacterial and antifungal effects that are characteristic of zinc oxide.

[0023] If the amount of Si is less than 0.01% by weight, the dispersibility of the agent will be poor and the polymer will deteriorate too quickly due to the photocatalytic effect of zinc oxide, which is undesirable.On the other hand, if the amount of Si is more than 10% by weight, the agent will become too hydrophobic, which will result in poor dispersibility in polyester and a decrease in spinnability during fiber production, which is undesirable.

[0024] [Product of average concentration of zinc oxide fine particles and fiber surface area] The antibacterial polyester fiber of the present invention has a product of the average concentration of zinc oxide microparticles on the fiber surface and the fiber surface area per 1 g of fiber of 1.0 to 3.0 wt% m 2 / g.

[0025] The excellent antibacterial properties of the present invention are affected by the concentration of zinc oxide microparticles on the fiber surface where the fiber comes into contact with the outside. The larger the area of ​​the fiber surface that comes into contact with the outside, the higher the antibacterial properties obtained, and the higher the concentration of zinc oxide microparticles in the polymer on the fiber surface, the higher the antibacterial properties obtained.

[0026] According to the studies of the present inventors, it was found that the product of the fiber surface area per gram of fiber and the average concentration of zinc oxide microparticles on the yarn surface that comes into contact with the outside is correlated with antibacterial properties. In the present invention, the product of the fiber surface area per 1 g of fiber and the average concentration of zinc oxide microparticles on the yarn surface that comes into contact with the outside is 1.0 to 3.0 wt% m 2 / g, preferably 1.0 to 2.0 wt% m 2 / g.

[0027] By setting this product within this range, the antibacterial activity value specified in JIS L 1902 after 50 industrial washes will be 5.0 or more, resulting in an antibacterial polyester fiber with excellent durability. 2 If this product is less than 3.0 wt% m / g, the antibacterial activity value specified in JIS L 1902 after 50 industrial washes will be less than 5.0, which is undesirable. 2 If the tensile strength exceeds 1 / g, the zinc oxide fine particles in the fiber will significantly reduce the thread strength, making it difficult to obtain durability, which is undesirable.

[0028] The antibacterial polyester fiber of the present invention has an antibacterial activity value of 5.0 or more, preferably 5.5 or more, as specified in JIS L 1902 after 50 industrial washings. If this antibacterial activity value is less than 5.0, sufficient bacteriostasis cannot be obtained when the fiber is combined with other fibers that do not have antibacterial properties. In this case, the number of normal skin bacteria and harmful bacteria on the fiber increases, making it difficult to use the fiber in applications that require cleanliness and hygienic management, such as curtains and sheets used in medical institutions.

[0029] [Polyester fiber] The polyester of the antibacterial polyester fiber of the present invention is a fiber-forming polyester composed of a dicarboxylic acid component mainly consisting of an aromatic dicarboxylic acid and a diol, such as polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polytetramethylene terephthalate, polycyclohexanedimethylene terephthalate, and polyethylene-2,6-naphthalenedicarboxylate. These polyester fibers may be copolymers in which a third component is copolymerized with a diol component such as polyalkylene glycol or cyclohexamethylene dimethylene terephthalate, or a dicarboxylic acid such as isophthalic acid or 5-sulfoisophthalic acid sodium salt, or a hydroxycarboxylic acid, or may further be a mixture of these various polyesters.

[0030] The antibacterial polyester fiber of the present invention is a fiber obtained by incorporating zinc oxide fine particles into the above polyester. This fiber may further contain silica and / or titanium oxide within a range that does not inhibit the antibacterial properties of the zinc oxide fine particles.

[0031] The cross-sectional shape of the antibacterial polyester fiber of the present invention may be a round cross-section, a flat cross-section, a multi-lobal cross-section, a cross-section, or a hollow cross-section. Since the larger the fiber surface area, the higher the antibacterial activity, the cross-sectional shape is preferably a cross-section (shown in FIG. 1), a flat cross-section (shown in FIG. 2), or a multi-lobal cross-section, and particularly preferably a cross-section (shown in FIG. 1). The degree of deformation of the antibacterial polyester fiber of the present invention is preferably 1.5 or more from the viewpoint of antibacterial properties.

[0032] [Fiber properties] The antibacterial polyester fiber of the present invention has a value of fiber breaking strength × √fiber breaking elongation, which indicates fiber toughness, of preferably at least 10, more preferably at least 12. If this value is less than 10, not only will yarn breakage and fluffing occur due to guide wear and the like during knitting and weaving, deteriorating operability, but also the fiber will be prone to tear when made into a fabric, resulting in poor practical stability, and is therefore undesirable.

[0033] The breaking strength of the antibacterial polyester fiber of the present invention is preferably 1.0 to 5.0 cN / dtex, more preferably 1.5 to 5.0 cN / dtex. If the breaking strength is less than 1.0 cN / dtex, not only will yarn breakage and fluffing occur due to guide wear and the like during knitting and weaving, deteriorating operability, but the fabric will also be prone to tearing when made into a fabric, resulting in poor practical stability, and this is undesirable. On the other hand, it is difficult to obtain fibers with a breaking strength exceeding 5.0 cN / dtex using a conventional melt spinning method.

[0034] The breaking elongation of the antibacterial polyester fiber of the present invention is preferably 10 to 200%, more preferably 15 to 180%, and even more preferably 20 to 150%. If the breaking elongation is less than 10%, yarn breakage is likely to occur during yarn production, which is undesirable because it causes fuzzing and yarn breakage during post-processing, weaving, knitting, etc., ultimately resulting in a decrease in the quality of the product. On the other hand, if the breaking elongation exceeds 200%, it is undesirable because it is prone to cause defects such as dye spots in higher-order processes, making the product less practical.

[0035] [Blended yarn] The antibacterial polyester fiber of the present invention may be blended with a fiber that does not have antibacterial properties to form a blended yarn. In this case, the blended yarn preferably contains 10% by weight or more of the antibacterial polyester fiber of the present invention. By using the antibacterial polyester fiber of the present invention in this range for the blended yarn, the antibacterial activity value specified in JIS L 1902 after 50 industrial washes can be made 3.0 or more, preferably 3.1 or more, and a blended yarn with high antibacterial and bacteriostatic activity can be obtained.

[0036] That is, according to the present invention, there is provided a blended yarn comprising the above-mentioned antibacterial polyester fiber and a fiber without antibacterial properties, wherein the antibacterial polyester fiber accounts for 10% by weight or more of the blended yarn, and the blended yarn has an antibacterial activity value of 3.0 or more as specified in JIS L 1902 after 50 industrial washes.

[0037] [Textile products] The antibacterial polyester fiber of the present invention can be used in blended yarns and textile products. When the antibacterial polyester fiber of the present invention is blended in an amount of 10% by weight or more based on the total weight of the fibers constituting the blended yarn or textile product, the antibacterial activity value can be increased to 3.0 or more, preferably 3.1 or more, resulting in blended yarns and textile products with high antibacterial and antibacterial activity. This is a remarkable effect not seen in conventional inventions.

[0038] On the other hand, the conventional method of adding antibacterial and antifungal agents such as zinc pyrithione in dyeing processes etc. places a heavy burden on the environment due to the wastewater. The present invention uses highly safe zinc oxide, and exhibits high antibacterial and antibacterial properties when combined with any other fiber, allowing for unprecedented freedom in combination.

[0039] According to the present invention, there is provided a blended yarn comprising the above-mentioned antibacterial polyester fiber and a fiber without antibacterial properties, wherein the antibacterial polyester fiber accounts for 10% by weight or more of the blended yarn and the blended yarn has an antibacterial activity value of 3.0 or more as defined in JIS L 1902 after 50 industrial washes, and further provided is a textile product comprising this blended yarn.

[0040] [Manufacturing method] The antibacterial polyester fiber of the present invention can be produced from polyester to which zinc fine particles have been added using a melt spinning apparatus in a conventional manner. The zinc oxide fine particles can be added to polyester by preparing a resin composition (master chip) containing zinc oxide fine particles at a high concentration in advance and adding this to polyester, or by adding the zinc oxide fine particles in powder form during polyester polymerization. A dispersant may be added when adding the zinc fine particles. [Example]

[0041] The present invention will be described in more detail below with reference to examples. Measurements and evaluation items in the examples were measured by the methods described below.

[0042] (1) Intrinsic viscosity number [η] of polyester component The intrinsic viscosity [η] was calculated using an Ostwald viscometer by extrapolating the ratio ηsp / C of the specific viscosity ηsp in o-chlorophenol at 35°C to the concentration C (g / 100 ml) to the concentration of zero, according to the following formula:

[0043]

number

[0044] (2) Fineness and Single Fiber Fineness The fineness was measured by JISL1013:2010 8.3.1 Method A, and the number of filaments was measured by the method described in JISL1013:2010 8.4. The single fiber fineness was calculated by dividing the fineness by the number of filaments.

[0045] (3) Breaking strength, breaking elongation (fiber breaking strength, fiber breaking elongation), fiber toughness Measurement was carried out using a Tensilon, a constant speed extension type tensile tester manufactured by Orientec Co., Ltd., based on JIS L1013:2010 8.5.1, with a grip distance of 20 cm and a pulling speed of 20 cm / min. The fiber toughness was calculated from the measured breaking strength (tensile strength) and breaking elongation (elongation rate) using the following formula. Fiber toughness = Breaking strength × √(Breaking elongation)

[0046] (4) Antibacterial properties after 50 industrial washes The obtained fibers were knitted into cylindrical samples using a circular knitting machine, and the samples were then scoured and washed industrially 50 times (60°C x 10 minutes).The antibacterial activity of the samples was evaluated after they were dried after washing. The antibacterial activity value was calculated using the following formula using cotton cloth as an untreated specimen. Antibacterial activity value = (log C i -logC l )-(logT i -logT l ) C i : Average number of viable bacteria on cotton standard cloth after 18 hours of incubation C l : Average number of viable bacteria immediately after inoculation of cotton standard cloth T i : Average number of viable bacteria on antibacterial treated fabric after 18 hours of incubation T l : Average number of live bacteria immediately after contact with antibacterial treated fabric Growth value: logC i -logC l Antibacterial standard value: (antibacterial activity value)-(growth value)≧0

[0047] (5) Zinc oxide concentration in fiber Seven grams of the collected fiber was heated in air at 600°C to decompose the polymer, the weight of the remaining ash was measured, and the intensity of the remaining ash was measured using an X-ray fluorescence analyzer (Model 3270, manufactured by Rigaku Corporation). The weight of zinc was calculated using a calibration curve prepared in advance using samples with known zinc contents, and the zinc oxide concentration in the fiber was calculated using the following formula. Zinc oxide concentration in fiber (wt%) = Ash weight (g) x Zinc concentration (wt%) x (65.38+16.00) / 65.38 / 7(g) x 100

[0048] (6) Particle size The particle size was determined by measuring the particle size distribution using a laser diffraction particle size distribution analyzer SALD-1000 manufactured by Shimadzu Corporation, and the value corresponding to 50% of the particles on the sieve was used as the particle size.

[0049] (7) Average concentration of zinc oxide particles on the fiber surface Using a transmission X-ray microscope SU3500 manufactured by Hitachi, Ltd., the concentration distribution of zinc oxide on the fiber surface was measured for the cross section and length direction of the fiber using an attached X-ray microscope EX-370 X-MAX N-20 manufactured by HORIBA (X-Ray MicroAnalysis). The average concentration (wt%) of zinc oxide microparticles on the fiber surface was calculated from the average concentration (n=30).

[0050] (8) Fiber surface area per gram of fiber A photograph of the fiber cross section was taken at 3000x magnification using a scanning electron microscope (SEM), the length of the fiber periphery in the photograph was measured, and the average value (n=50) was used to calculate the fiber surface area per 1g of fiber using the following formula. Fiber surface area per gram of fiber (m 2 / g) = 10000 (m) / single fiber fineness (g) × average outer peripheral length of fiber (m)

[0051] (9) Amount of Si relative to zinc oxide Seven grams of the collected fiber was melted and molded into a plate, and its strength was measured using an X-ray fluorescence analyzer (Model 3270, manufactured by Rigaku Corporation). The zinc and silicon concentrations were measured using calibration curves prepared in advance using samples with known contents. The amount of silicon relative to zinc oxide was then calculated using the following formula: Amount of Si relative to zinc oxide (wt%) = Si concentration (wt%) / (zinc concentration (wt%) × (65.38 + 16.00) / 65.38) × 100

[0052] (10) Atypicality A photograph of the fiber cross section was taken at 3000x magnification using a scanning electron microscope (SEM), and the diameters of the inscribed circle and circumscribed circle of the fibers in the photograph (n number = 50) were measured. The average value of the inscribed circle diameters (n number = 50) was taken as the inscribed circle diameter (r), and the average value of the circumscribed circle diameters (n number = 50) was taken as the circumscribed circle diameter (R). The irregularity was calculated using the following formula. Degree of irregularity = circumscribed circle diameter (R) / inscribed circle diameter (r)

[0053] (11) Fiber diameter Assuming that the fibers are perfectly round, the fiber diameter was calculated from the fineness and density.

[0054] (12) Fiber density This was done according to JISL1013:2010 8.17.1.

[0055] (13) Fabric weight This was carried out according to JIS L1096:2010, 8.3.2 (mass per unit area under standard conditions), Method A.

[0056] Example 1 Chips of polyethylene terephthalate containing no titanium oxide and having an intrinsic viscosity of 0.65 dL / g were prepared. A polyethylene terephthalate master chip having an intrinsic viscosity of 0.30 dL / g and a content of 60 wt % zinc oxide fine particles with a particle diameter of 100 nm and an Si concentration of 0.10 wt % relative to zinc oxide was prepared.

[0057] The chips and the master chips were mixed so that the zinc oxide microparticle content per total chip weight was 5.0 wt %, and the mixture was dried at 160°C for 10 hours to reduce the moisture content to 50 ppm, resulting in a polymer for spinning. This spinning polymer was melted at 285°C, spun using a spinneret with 72 holes of 0.27 mm diameter, and wound up at 1000 m / min to obtain an undrawn yarn consisting of 72 filaments of 340 dtex.

[0058] This undrawn yarn was wound around a roller preheated to 90°C, drawn 3.8 times, passed through a non-contact heater at 200°C, and wound up at 600 m / min to obtain a drawn yarn with 72 filaments of 84 dtex. A cylindrical knitted fabric was produced using this drawn yarn. This fabric was then relaxed, washed, dried, and pre-set, and its antibacterial properties were evaluated. The evaluation results are shown in Table 1.

[0059] Example 2 In Example 1, the master chips were adjusted to 11.7% by weight per total chip weight so that the zinc oxide microparticle content per total chip weight was 7% by weight, and the other procedures were the same as in Example 1 to obtain a polymer for spinning.

[0060] This was used for spinning using a spinneret with 36 holes of 0.35 mm diameter and wound at 1000 m / min to obtain an undrawn yarn with 36 filaments of 340 dtex. After drawing this undrawn yarn, a drawn yarn with 36 filaments of 84 dtex was obtained. A cylindrical knitted fabric was produced using this drawn yarn in the same manner as in Example 1, and its antibacterial properties were evaluated. The evaluation results are shown in Table 1.

[0061] Example 3 In Example 1, the content of master chips relative to the total chip weight was 16.7 wt % so that the content of zinc oxide microparticles relative to the total chip weight was 10 wt %. Otherwise, a spinning polymer was obtained in the same manner as in Example 1.

[0062] This was used for spinning using a spinneret with 48 holes of 0.37 mm diameter and wound at 1000 m / min to obtain an undrawn yarn with 48 filaments of 635 dtex. After drawing this undrawn yarn, a drawn yarn with 48 filaments of 167 dtex was obtained. A cylindrical knitted fabric was produced using this drawn yarn in the same manner as in Example 1, and its antibacterial properties were evaluated. The evaluation results are shown in Table 1.

[0063] Example 4 A polymer for spinning was obtained in the same manner as in Example 1. This was used for spinning using a spinneret with 72 holes of 0.23 mm diameter and wound at 1000 m / min to obtain an undrawn yarn with 72 filaments of 176 dtex. After drawing this undrawn yarn, a drawn yarn with 72 filaments of 48 dtex was obtained. A cylindrical knitted fabric was produced using this drawn yarn in the same manner as in Example 1, and its antibacterial properties were evaluated. The evaluation results are shown in Table 1.

[0064] Example 5 A drawn yarn having 72 filaments of 84 dtex was obtained in the same manner as in Example 1, except that the Si concentration relative to zinc oxide was 0.10 wt % and the particle diameter of the zinc oxide microparticles was 50 nm. A cylindrical knitted fabric was produced using this drawn yarn in the same manner as in Example 1, and its antibacterial properties were evaluated. The evaluation results are shown in Table 1.

[0065] Example 6 In Example 1, the Si concentration relative to zinc oxide was set to 0.10 wt%, the particle diameter of the zinc oxide microparticles was set to 1700 nm, and the master chips per total chip weight was set to 16.7 wt%, so that the zinc oxide content per total chip weight was 10 wt%, and a polymer for spinning was obtained in the same manner as in Example 1.

[0066] This was used for spinning using a spinneret with 36 holes of 0.35 mm diameter and wound at 1000 m / min to obtain an undrawn yarn of 340 dtex and 36 filaments. After drawing this undrawn yarn, a drawn yarn of 84 dtex and 36 filaments was obtained. A cylindrical knitted fabric was produced using this drawn yarn in the same manner as in Example 1, and its antibacterial properties were evaluated. The evaluation results are shown in Table 1.

[0067] Example 7 In Example 1, in addition to the master chips containing zinc oxide microparticles, polyethylene terephthalate master chips containing titanium oxide particles with a particle diameter of 150 nm, the content of which was 60% by weight of the chip weight, and having an intrinsic viscosity of 0.30 dL / g were mixed so that the zinc oxide content relative to the total chip weight was 5% by weight.

[0068] Spinning and drawing were carried out in the same manner as in Example 1 except for this, and a drawn yarn having 72 filaments of 84 dtex was obtained. A cylindrical knitted fabric was produced using this drawn yarn in the same manner as in Example 1, and its antibacterial properties were evaluated. The evaluation results are shown in Table 1.

[0069] Example 8 <Preparing the polymer tip for the lead> Only polyethylene terephthalate chips containing no titanium oxide and having an intrinsic viscosity of 0.65 dL / g were dried at a drying temperature of 160° C. for 10 hours to reduce the moisture content to 50 ppm, thereby obtaining polymer chips for the core.

[0070] <Preparing the polymer tip for the sheath> Chip B was mixed with titanium oxide-free polyethylene terephthalate chip A with an intrinsic viscosity of 0.65 dL / g so that the zinc oxide concentration relative to the total chip weight was 5.0 wt%. Chip B was a polyethylene terephthalate master chip containing zinc oxide microparticles with a particle diameter of 100 nm and an Si concentration of 0.10 wt% relative to the zinc oxide, with a zinc oxide microparticle content of 60 wt% and an intrinsic viscosity of 0.30 dL / g. The mixture of chips A and chips B was dried at 160° C. for 10 hours to a moisture content of 50 ppm to obtain polymer chips for the sheath.

[0071] <Manufacturing of composite fibers> Using core polymer chips and sheath polymer chips in a composite ratio of core:sheath = 50:50 (mass ratio), the spinning was carried out at a melt temperature of 285°C using a die nozzle with a hole diameter of 0.25 mm x 72 holes, and the spinning was taken up at 1000 m / min.The spinning was then wound around a roller heated to 90°C and stretched 3.8 times, passed through a non-contact heater at 200°C, and wound up at 600 m / min to obtain a stretched yarn with 72 filaments of 84 dtex.

[0072] <Making cylindrical knitted fabric> A cylindrical knitted fabric was produced using this drawn yarn in the same manner as in Example 1, and its antibacterial properties were evaluated. The evaluation results are shown in Table 1.

[0073] Example 9 In Example 1, a partially oriented yarn of 140 dtex and 72 filaments was obtained by setting the take-up speed during spinning to 3000 m / min. This partially oriented yarn was false-twisted under the following conditions to obtain a false-twist textured yarn of 87 dtex and 72 filaments. A tubular knitted fabric was produced in the same manner as in Example 1, except that this false-twist textured yarn was used. The fabric was then relaxed, washed, dried, and pre-set, and its antibacterial properties were evaluated. The evaluation results are shown in Table 1.

[0074] Example 10 Spinning was carried out in the same manner as in Example 1, except that a cross-section spinneret with a slit width of 0.05 mm and a slit length of 0.4 mm was used, and an undrawn yarn of 340 dtex and 72 filaments was obtained. This undrawn yarn was wound around a roller heated to 90°C, drawn 3.5 times, passed through a non-contact heater at 200°C, and wound up at 600 m / min, and a drawn yarn of 97 dtex and 72 filaments was obtained. The cross-sectional irregularity of this drawn yarn was 2.5. A tubular knitted fabric was produced using this drawn yarn. This fabric was then relaxed, washed, dried, and pre-set, and its antibacterial properties were evaluated. The evaluation results are shown in Table 1.

[0075] [Table 1]

[0076] Example 11 The warp yarn was a 36 filament stretched yarn of 84 dtex, and the weft yarn was the stretched yarn obtained in Example 1, which accounted for 50% of the fabric weight. The warp density was 105 threads / inch, the weft density was 83 threads / inch, and the fabric had a plain weave structure with a density of 70 g / m 2 The fabrics were prepared and their antibacterial properties were evaluated. The results are shown in Table 2.

[0077] Example 12 A fabric was produced with the same plain weave structure and basis weight density as in Example 11, except that the drawn yarn obtained in Example 1 was used as the weft yarn so that it accounted for 25% by weight of the fabric, and the antibacterial properties were evaluated. The results are shown in Table 2.

[0078] Example 13 The warp yarn was made of a 84 dtex, 36 filament drawn yarn, and the weft yarn was made of half the drawn yarn obtained in Example 1 and half the 84 dtex, 36 filament drawn yarn, with a plain weave structure so that the warp density was 105 threads / inch and the weft density was 83 threads / inch, with a density of 70 g / m 2 The fabrics were prepared and their antibacterial properties were evaluated. The results are shown in Table 2.

[0079] Example 14 The warp yarn was a 167 dtex, 72 filament false twisted drawn yarn made solely of polyethylene terephthalate containing 2.5% by weight of titanium oxide and having an intrinsic viscosity of 0.65 dL / g. The weft yarn was a two-ply drawn yarn obtained in Example 2. The warp yarn had a warp density of 118 threads / inch and a weft density of 56 threads / inch. The fabric had a plain weave twill structure with a density of 170 g / m². 2 The fabrics were prepared and their antibacterial properties were evaluated. The results are shown in Table 2.

[0080] Comparative Example 1 In Example 2, spinning and drawing were carried out in the same manner as in Example 2, except that zinc oxide microparticles having an Si concentration of 0.10 wt% relative to the zinc oxide and a particle diameter of 5000 nm were used instead of the zinc oxide microparticles having an Si concentration of 0.10 wt% relative to the zinc oxide and a particle diameter of 100 nm.An attempt was made to obtain a drawn yarn of 84 dtex and 36 filaments, but a sample could not be obtained due to yarn breakage.

[0081] Comparative Example 2 In Example 1, spinning and drawing were carried out in the same manner as in Example 1, except that the content of zinc oxide microparticles per total chip weight was 1.0 wt %, and a drawn yarn of 84 dtex and 72 filaments was obtained. A cylindrical knitted fabric was produced using this drawn yarn. This fabric was then relaxed, washed, dried, and pre-set, and its antibacterial properties were evaluated. The evaluation results are shown in Table 1.

[0082] Comparative Example 3 In Example 1, spinning and drawing were carried out in the same manner as in Example 1, except that the content of zinc oxide microparticles per total chip weight was 4.0 wt %, and a drawn yarn of 84 dtex and 72 filaments was obtained. A cylindrical knitted fabric was produced using this drawn yarn. This fabric was then relaxed, washed, dried, and pre-set, and its antibacterial properties were evaluated. The evaluation results are shown in Table 1.

[0083] Comparative Example 4 In Example 1, the zinc oxide microparticle content per total chip weight was adjusted to 4.5 wt %, and spinning was performed using a spinneret with 24 holes of 0.4 mm diameter, and drawing was performed in the same manner as in Example 1, except that a yarn with 84 dtex and 24 filaments was obtained. A cylindrical knitted fabric was produced using this drawn yarn. This fabric was then relaxed, washed, dried, and pre-set, and its antibacterial properties were evaluated. The evaluation results are shown in Table 1.

[0084] Comparative Example 5 <Preparing the polymer tip for the lead> Chip B was mixed with titanium oxide-free polyethylene terephthalate chip A with an intrinsic viscosity of 0.65 dL / g so that the zinc oxide concentration relative to the total chip weight was 5.0 wt%. Chip B was a polyethylene terephthalate master chip containing zinc oxide microparticles with a particle diameter of 100 nm and an Si concentration of 0.10 wt% relative to the zinc oxide, with a zinc oxide microparticle content of 60 wt% and an intrinsic viscosity of 0.30 dL / g. The mixture of chips A and chips B was dried at 160° C. for 10 hours to a moisture content of 50 ppm to obtain polymer chips for the sheath.

[0085] <Preparing the polymer tip for the sheath> Only polyethylene terephthalate chips containing no titanium oxide and having an intrinsic viscosity of 0.65 dL / g were dried at a drying temperature of 160° C. for 10 hours to reduce the moisture content to 50 ppm, thereby obtaining polymer chips for the core.

[0086] <Manufacturing of composite fibers> Using core polymer chips and sheath polymer chips in a composite ratio of core:sheath = 50:50 (mass ratio), the spinning was carried out at a melt temperature of 285°C using a die nozzle with a hole diameter of 0.25 mm x 72 holes, and the spinning was taken up at 1000 m / min.The spinning was then wound around a roller heated to 90°C and stretched 3.8 times, passed through a non-contact heater at 200°C, and wound up at 600 m / min to obtain a stretched yarn with 72 filaments of 84 dtex.

[0087] <Making cylindrical knitted fabric> A cylindrical knitted fabric was produced using this drawn yarn in the same manner as in Example 1, and its antibacterial properties were evaluated. The evaluation results are shown in Table 1.

[0088] Comparative Example 6 In Example 3, spinning and drawing were carried out in the same manner as in Example 1, except that the content of zinc oxide microparticles per total chip weight was 22.0 wt %, and a drawn yarn with a filament density of 84 dtex and 36 was obtained. A cylindrical knitted fabric was produced using this drawn yarn. This fabric was then relaxed, washed, dried, and pre-set, and its antibacterial properties were evaluated. The evaluation results are shown in Table 1.

[0089] Comparative Example 7 The warp yarn was the 84 dtex, 72 filament drawn yarn obtained in Example 1, and the weft yarn was the drawn yarn obtained in Comparative Example 3. The warp density was 105 threads / inch and the weft density was 83 threads / inch. The plain weave structure was used, and the density was 70 g / m 2 The fabrics were prepared and their antibacterial properties were evaluated. The results are shown in Table 2.

[0090] Comparative Example 8 The warp yarn was the 84 dtex, 72 filament drawn yarn obtained in Example 1, and the weft yarn was half the drawn yarn obtained in Comparative Example 3 and half the 84 dtex, 72 filament drawn yarn obtained in Example 1. The warp yarn was a plain weave with a warp density of 105 threads / inch and a weft density of 83 threads / inch, and the fabric had a density of 70 g / m 2 The fabrics were prepared and their antibacterial properties were evaluated. The results are shown in Table 2.

[0091] Comparative Example 9 The warp yarn was the 84 dtex, 72 filament drawn yarn obtained in Example 1, and the weft yarn was the drawn yarn obtained in Comparative Example 2. The warp density was 105 threads / inch and the weft density was 83 threads / inch, and the fabric had a plain weave structure with a density of 70 g / m 2 The fabrics were prepared and their antibacterial properties were evaluated. The results are shown in Table 2.

[0092] [Table 2] [Industrial Applicability]

[0093] The antibacterial polyester fiber of the present invention can be used in textile products such as clothing.

Claims

1. An antibacterial polyester fiber containing zinc oxide fine particles, characterized in that the antibacterial polyester fiber simultaneously satisfies the following requirements (A) to (C): (A) The particle diameter of the zinc oxide fine particles is 10 to 2000 nm, and the content of the zinc oxide fine particles is 2 to 20% by weight based on the weight of the fiber. (B) The product of the average concentration of zinc oxide fine particles on the fiber surface and the fiber surface area per 1 g of fiber is 1.0 to 3.0 wt.% m ２ / g (C) After 50 industrial washes, the antibacterial activity value specified in JIS L 1902 is 5.0 or more.

2. 2. The antibacterial polyester fiber according to claim 1, wherein the zinc oxide fine particles contain 0.01 to 10% by weight of Si element based on the weight of the zinc oxide fine particles.

3. 2. The antibacterial polyester fiber according to claim 1, wherein the degree of deformation of the antibacterial polyester fiber is 1.5 or more.

4. 2. The antibacterial polyester fiber according to claim 1, wherein the toughness of the antibacterial polyester fiber is 10 or more.

5. A blended yarn comprising the antibacterial polyester fiber according to claim 1 and a fiber without antibacterial properties, wherein the antibacterial polyester fiber accounts for 10% by weight or more of the blended yarn, and the blended yarn has an antibacterial activity value of 3.0 or more as specified in JIS L 1902 after 50 industrial washes.

6. A textile product comprising the blended yarn according to claim 5.

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