Polyester crimped staple fibers containing regenerated polyester with excellent antibacterial properties, webs, nonwoven fabrics, and spun yarns obtained using the same, methods for producing the same, and fiber processed products obtained using the same

Abstract

To provide a nonwoven fabric obtained using a web comprising a silver-based antibacterial agent and recycled polyester, which has excellent antibacterial properties and fiber-blending cardability, exhibits minimal blending unevenness when blended with other non-antibacterial staple fibers, possesses superior antibacterial imparting ability, and excels in see-through resistance and mechanical strength.SOLUTION: A nonwoven fabric comprises a thermoplastic polyester including recycled polyester and an inorganic antibacterial agent in which an antibacterial metal component, at least partially composed of silver, is supported on an inorganic compound, the nonwoven fabric uses, as main fibers, antibacterial crimped staple fibers and non-antibacterial crimped staple fibers with an antibacterial activity value of 2.5 or higher and a fiber thickness of 1.0 to 10.0 dtex, the antibacterial crimped staple fibers account for 10 to 90 mass%, and the non-antibacterial crimped staple fibers account for 90 to 10 mass%, relative to 100 mass% of the total main fibers, the main fibers are blended and carded to form a web in which inter-fiber bonding is reinforced, the crimp of the main fibers is a two-dimensional mechanical crimp with a crimp count of 5 to 35 crimps / inch, a crimp ratio of 5 to 40%, and a residual crimp ratio of 3 to 35%, and the basis weight of the nonwoven fabric is 180 to 350 g / m2.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to polyester crimped staple fibers containing recycled polyester excellent in antibacterial properties and carding properties with mixed cotton, webs, non-woven fabrics and spun yarns obtained using the same, methods for producing them, and fiber processed products obtained using them. More specifically, as raw materials, it is a polyester antibacterial crimped staple fiber containing environmentally friendly recycled polyester and a silver-based antibacterial agent. When the antibacterial crimped staple fiber is mixed with other non-antibacterial crimped staple fibers, there is less unevenness in the mixed cotton, it has excellent antibacterial property imparting ability, and relates to a web excellent in bulkiness and mechanical strength, a non-woven fabric and a spun yarn obtained using the web.

Background Art

[0002] The sale of antibacterial processed products such as plastics and fibers began in Japan in the 1970s and became distributed in the market mainly in Asian countries due to the occurrence of enterohemorrhagic Escherichia coli O-157 and severe acute respiratory syndrome SARS. Recently, especially triggered by the global pandemic of novel coronavirus infection, the attention to functional materials with antiviral and antibacterial effects has been increasing.

[0003] Thermoplastic polyester, especially polyethylene terephthalate (PET), is widely used as plastic molded products, sheets, synthetic fibers, etc. because of its excellent balance of mechanical properties, heat resistance, moldability, chemical resistance, etc. and its low cost. As SDGs and ESG investment have become a global trend, recycled products, which were previously limited to specific fields, have come to be actively used. Recycled polyester is a recycled material made from recycled PET using PET bottles, PET scraps, PET end materials, etc. as raw materials, or other polyesters such as PBT and PEN as raw materials. Recycled polyester fibers obtained by fiberizing recycled PET have come to be widely used in automotive interior materials, cotton, clothing, fabrics for interior miscellaneous goods, etc. However, compared with the case of using virgin PET derived from petroleum as a raw material, the quality of the raw material is unstable, so the range of use for cotton, non-woven fabrics and spun yarns made from staple fibers is limited.

[0004] A non-woven fabric that forms a fabric-like fibrous aggregate is technically formed by combining a fleece-like cotton aggregate called a web and a bonding process that physically and chemically joins and entangles it. The main methods of forming the fleece include the dry method of carding short fibers using a carding machine and arranging them in a certain direction or randomly with an air current called an air-laid, the wet method of dispersing short fibers in water and lifting them up in a net-like shape to form a fleece, and the spunbond method of directly eluting and spinning a molten raw material resin from the tip of a nozzle to form a fleece with continuous long fibers. As methods of bonding fibers together, there are the chemical bond method of impregnating or spraying an emulsion-based adhesive resin onto the fleece and heating and drying it to bond the fiber intersections, the thermal bond method of passing a fleece mixed with low-melting thermally fusible fibers through between hot rolls for thermocompression bonding or blowing hot air to bond the fibers together, and the needle punch method of repeatedly piercing a fleece up and down at high speed with needles and entangling the fibers with protrusions called barbs engraved on the needles. The needle punch method is characterized by being highly bulky and having no fiber separation, and it is used for productization alone or in combination with another bonding method. On the other hand, spun yarn is made through a spinning process of aligning and kneading short fibers in one direction.

[0005] On the other hand, as a method of antibacterializing fibers, Patent Document 1 discloses polyester staple fibers having a single fiber fineness of 2 to 8 denier, containing 0.1 to 2.0% by mass of at least one silver-based antibacterial agent, having a sterilization rate against Staphylococcus aureus of less than 26%, and showing a sterilization rate of 80% or more after carding. Patent Document 2 also discloses an antibacterial spherical cotton in which a plurality of polyester staple fibers containing 0.1 to 12.0% by mass of an inorganic antibacterial agent, having a single fiber fineness of 2 to 15 d (denier), a fiber length of 25 to 64 mm, and being mechanically crimped are intertwined to form a spherical shape with an average diameter of 3 to 20 mm. Furthermore, Patent Document 3 discloses antibacterial polyester fibers containing a heat-resistant discoloration inhibitor and a silver-based inorganic antibacterial agent that have no discoloration during the manufacturing process and after manufacturing and also have excellent antibacterial performance.

[0006] Further, Patent Document 4 discloses an antibacterial polyester fiber containing an inorganic antibacterial agent carrying a silver component, having a silver component content rate of 30 to 200 ppm, a zinc content rate of 10 ppm or less, and a fiber-fiber dynamic friction coefficient of 0.20 to 0.35 indicating the presence of optimal protrusions on the fiber surface. Furthermore, Patent Document 5 discloses a polyester fiber obtained by an optimal combination of the limiting viscosities of an inorganic antibacterial agent-containing masterbatch and a polyester resin as the main body of the fiber, and the number of inorganic antibacterial agent particles per unit cross-sectional area in the surface layer portion is 1.3 times or more the number of inorganic antibacterial agent particles per unit cross-sectional area in the central portion as observed by electron microscopy of the cross-section of the fiber. Also, Patent Document 6 discloses an antibacterial and flame-retardant polyester fiber containing a phosphorus-based flame retardant and 0.01 to 10.0% by mass of an antibacterial agent, having a whiteness of 85.00 or more, and the polyester may be recycled polyester. Furthermore, Patent Document 7 discloses a hollow-crimped polyester having a crimp rate of 9 to 30 crimps / inch, a three-dimensional crimp (stereoscopic crimp) with a crimp rate of 20 to 50%, and a crimp elastic modulus of 80% or more.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Patent Document 7

Summary of the Invention

Problems to be Solved by the Invention

[0008] The present invention relates to polyester crimped staple fibers containing a silver-based antibacterial agent and recycled polyester, which are excellent in antibacterial properties and carding properties with mixed cotton, a web obtained using the same, a non-woven fabric and a spun yarn obtained using the web, and when mixed with other non-antibacterial staple fibers, the non-woven fabric and the spun yarn have less unevenness in mixed cotton, excellent antibacterial property imparting ability, and also excellent scouring resistance and mechanical strength.

[0009] According to Patent Document 1, by performing a carding treatment, the antibacterial agent inside the fiber is exposed on the surface and shows a good antibacterial rate. According to Patent Document 2, it is said that spherical cotton excellent in sufficient antibacterial properties and bulkiness can be obtained. According to Patent Document 4, by using fibers having a fiber-fiber dynamic friction coefficient within a specific range, the formation of protrusions on the surface of the inorganic antibacterial agent can be controlled, high antibacterial performance can be imparted, and discoloration over time, thread breakage during production, and abnormal winding shape can be prevented. Also, according to Patent Document 5, it has been reported that if the difference in the intrinsic viscosity between the inorganic antibacterial agent-containing masterbatch and the polyester resin that is the main body of the fiber is small, the concentration on the surface of the antibacterial agent is insufficient, and if the difference in the intrinsic viscosity is large, fiber strength cannot be obtained. However, none of these cited documents mention excellent carding properties with mixed cotton, no unevenness in mixed cotton, the influence of mixed cotton on antibacterial properties, or the inclusion of recycled polyester.

[0010] On the other hand, Patent Document 3 discloses that antibacterial polyester fibers can be mixed or compounded with fibers that do not contain an antibacterial agent, but does not mention the influence of the crimping method on antibacterial properties and unevenness in mixed cotton, or the inclusion of recycled polyester. Also, Patent Document 6 describes that the polyester used may be recycled polyester, but does not mention the mixing of antibacterial fibers and non-antibacterial fibers or unevenness in mixed cotton. Further, Patent Document 7 relates to hollow crimped polyester and does not mention antibacterial properties.

[0011] Here, for example, in fiber products for automobile interiors, strict product specifications and stable quality are required. However, in addition to waste PET bottles and waste PET films with unstable quality, recycled PET with unstable quality, such as PET blocks and end materials generated during manufacturing, is widely used. Usually, instead of using single fibers, it is common to blend multiple crimped staple fibers with different colors, physical properties, costs, etc. to satisfy the required characteristics. Therefore, the cardability during the blending of crimped staple fibers obtained using recycled PET is an important factor for productization.

Means for Solving the Problems

[0012] In order to meet the need for the development of functional materials with antiviral and antibacterial effects, which originated from the global spread of infectious diseases, the present inventors, instead of manufacturing antibacterial fibers mainly using virgin PET derived from petroleum as a raw material, attempted to produce antibacterial crimped staple fibers using recycled PET with unstable quality and to commercialize antibacterial fibers, aiming to contribute to the SDGs and improve ESG investment. As a result, it was found that even when using recycled polyester with unstable quality as a raw material, by using a specific antibacterial agent, effective antibacterial performance can be achieved with a small amount of addition. However, simply specifying a particular antibacterial agent did not result in a product that fully satisfied the mechanical strengths such as yield, strength, and elongation. Therefore, as a result of intensive studies on the blending with non-antibacterial staple fibers, it was found that antibacterial performance, cardability during carding, yield, uniformity of nonwoven fabrics, etc. greatly depend on the shape and crimp performance of the staple fibers, leading to the completion of the present invention. In addition, when using an inorganic antibacterial agent containing a silver component supported on alkaline silica, it was found that during the stretching process, it easily migrates to the fiber surface due to blooming, and high antibacterial performance can be exhibited even with a small addition amount. By performing the same process under wet conditions, the effect can be enhanced, strengthening the present invention. That is, the present invention provides the following (1) to (22).

[0013] (1) An antibacterial crimped staple fiber obtained by a melt-kneading spinning process, a drawing process, a crimping process, and a cutting process of a resin raw material containing a thermoplastic polyester containing recycled polyester and an inorganic antibacterial agent in which an antibacterial metal component, at least a part of which is a silver component, is supported on an inorganic compound, having an antibacterial activity value of 2.5 or more, a fiber fineness of 1.0 to 10.0 decitex, and a two-dimensional mechanical crimp, wherein the number of crimps of the mechanical crimp is 5 to 35 crests / inch, the crimp ratio is 5 to 40%, and the residual crimp ratio is 3 to 35%, and being excellent in blending and carding properties with a non-antibacterial crimped staple fiber; (2) The antibacterial crimped staple fiber according to (1), wherein the content of the silver component is 1 to 25 mass ppm; (3) The antibacterial crimped staple fiber according to (1) or (2), which is a hollow fiber having a hollowness of 5 to 40%; (4) The antibacterial crimped staple fiber according to any one of (1) to (3), which contains a phosphorus-based flame retardant and exhibits flame retardancy with 3 or more flame contact times; (5) The antibacterial crimped staple fiber according to any one of (1) to (4), wherein the recycled polyester is 20 to 100 mass% and the virgin polyester is 80 to 0 mass% based on 100 mass% of the total amount of the thermoplastic polyester; (6) The antibacterial crimped staple fiber according to any one of (1) to (5), wherein the inorganic antibacterial agent contains a silver component supported on alkaline silica as an inorganic compound, and the concentration of the inorganic antibacterial agent is 0.05 to 0.85 mass%; (7) The antibacterial crimped staple fiber according to (6), wherein the drawing process is performed in a state where the fiber surface is wet; (8) An antibacterial crimped staple fiber obtained by a melt-kneading spinning process, a drawing process, a crimping process, and a cutting process of a resin raw material containing a thermoplastic polyester containing recycled polyester and an inorganic antibacterial agent in which an antibacterial metal component that is at least partially a silver component is supported on an inorganic compound, and the fiber thickness is 1.0 to 10.0 decitex, and a non-antibacterial crimped staple fiber are used as the main fibers. With respect to 100% by mass of the total amount of the main fibers, the antibacterial crimped staple fiber is 10 to 90% by mass, and the non-antibacterial crimped staple fiber is 90 to 10% by mass. The main fibers are blended and carded, and the crimp of the main fibers is a two-dimensional mechanical crimp. The number of crimps of the mechanical crimp is 5 to 35 crests / inch, the crimp ratio is 5 to 40%, and the residual crimp ratio is 3 to 35%. Further, the antibacterial activity value is 2.0 or more; a web; (9) The web according to (8), wherein the content of the silver component is 0.5 to 15 mass ppm; (10) The web according to (8) or (9), wherein the antibacterial crimped fiber is a hollow fiber having a hollowness of 5 to 40%; (11) The web according to any one of (8) to (10), wherein the antibacterial crimped staple fiber contains a phosphorus-based flame retardant and is a flame-retardant fiber showing flame-retardancy with 3 or more times of flame contact; (12) The web according to any one of (8) to (11), wherein with respect to 100% by mass of the total amount of the thermoplastic polyester used for the main fibers, the recycled polyester is 20 to 100% by mass, and the virgin polyester is 80 to 0% by mass; (13) The web according to any one of (8) to (12), wherein the inorganic antibacterial agent of the antibacterial crimped staple fiber is an inorganic antibacterial agent containing a silver component supported on alkaline silica as an inorganic compound, and the concentration of the inorganic antibacterial agent in the web is 0.05 to 0.085% by mass; (14) The web according to (13), wherein the stretching process is performed in a state where the fiber surface is wet; (15) A melt-kneading spinning process, a drawing process, a crimping process, and a cutting process of a resin raw material containing a thermoplastic polyester containing recycled polyester and an inorganic antibacterial agent in which an antibacterial metal component, at least part of which is a silver component, is supported on an inorganic compound, and an antibacterial crimped staple fiber having a fiber thickness of 1.0 to 10.0 decitex is obtained. The antibacterial crimped staple fiber and the non-antibacterial crimped staple fiber are used as the main fibers. Based on 100% by mass of the total amount of the main fibers, the antibacterial crimped staple fiber is 10 to 90% by mass, and the non-antibacterial crimped staple fiber is 90 to 10% by mass. A non-woven fabric obtained by strengthening the bond between fibers by blending and carding the main fibers, wherein the crimp of the main fibers is a two-dimensional mechanical crimp, the number of crimps of the mechanical crimp is 5 to 35 crests / inch, the crimp ratio is 5 to 40%, and the residual crimp ratio is 3 to 35%. The basis weight of the non-woven fabric is 180 to 350 g / m 2 and further having an antibacterial activity value of 2.0 or more; a non-woven fabric; (16) The non-woven fabric according to (15), wherein the silver component content is 0.5 to 15 ppm by mass; (17) The non-woven fabric according to (15) or (16), wherein the antibacterial crimped staple fiber is a hollow fiber having a hollowness of 5 to 40%; (18) The non-woven fabric according to any one of (15) to (17), wherein the antibacterial crimped staple fiber contains a phosphorus-based flame retardant and is a flame-retardant fiber showing flame-retardancy with 3 or more flame contact times; (19) The non-woven fabric according to any one of (15) to (18), wherein based on 100% by mass of the total amount of the thermoplastic polyester used for the main fibers, the recycled polyester is 20 to 100% by mass, and the virgin polyester is 80 to 0% by mass; (20) The non-woven fabric according to any one of (15) to (19), wherein the inorganic antibacterial agent is an inorganic antibacterial agent containing a silver component supported on alkaline silica as an inorganic compound, and the concentration of the inorganic antibacterial agent in the non-woven fabric is 0.05 to 0.085% by mass; (21) The non-woven fabric according to (20), wherein the drawing process is performed in a state where the fiber surface is wet; An antibacterial fiber processed product obtained by using the antibacterial crimped staple fiber according to any one of (1) to (7), the web according to any one of (8) to (14), or the nonwoven fabric according to any one of (15) to (21).

Advantages of the Invention

[0014] According to the present invention, as the main fiber, by using a thermoplastic polyester antibacterial staple fiber containing a regenerated polyester with mechanical crimps and using a specific silver-based antibacterial agent, and a thermoplastic polyester non-antibacterial staple fiber with mechanical crimps as staple fibers for mixing cotton, compared with staple fibers with potential crimps that are generally used as futon cotton, it is excellent in carding property and yield, and a web (cotton) excellent in antibacterial property, compression rate and recovery rate, and subsequently, by adding needles, adhesives, heat, etc. to strengthen the bond between fibers, it is excellent in antibacterial property, colorability and flame retardancy, and also excellent in design, mechanical strength and elongation, and has no fluff, low basis weight and excellent lightness. A nonwoven fabric or spun yarn can be provided. Furthermore, the silver-based antibacterial agent used in the present invention can exhibit antibacterial performance by adding a small amount, so the burden on fibers recognized as foreign substances is small, and it is suitable for the production of fibers with difficulties in yield and quality, such as hollow fibers and flame retardant fibers, and since the antibacterial agent is kneaded into the resin, it is excellent in durability, sustainability, etc.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present invention will be described with reference to the attached drawings. Note that the dimensional ratios in the drawings are exaggerated for the convenience of explanation and may be different from the actual ratios.

[0017] The present invention includes a thermoplastic polyester containing recycled polyester and a specific inorganic antibacterial agent, has an antibacterial activity value of 2.5 or more, a specific fiber thickness, and a specific crimp function, and is excellent in blending with non-antibacterial crimped staple fibers and carding property, an antibacterial crimped staple fiber, a web excellent in antibacterial property, compression ratio, and recovery rate obtained from the antibacterial crimped staple fiber, and a non-woven fabric or spun yarn obtained by strengthening the bond between fibers of the web, excellent in antibacterial property, design, mechanical strength and elongation, without scale, with a low basis weight and excellent lightness, and further an antibacterial fiber processed product obtained therefrom. In addition, the inorganic antibacterial agent containing a silver component supported on alkaline silica easily migrates to the fiber surface by blooming in the stretching process, and can exhibit high antibacterial performance even with a small addition amount, and the effect can be enhanced by performing the process under wet conditions. In this specification, unless otherwise specified, the numerical range indicated by "~" includes the upper and lower limits. For example, "10~30%" means "10% or more and 30% or less".

[0018] <Main fiber (thermoplastic polyester antibacterial crimped staple fiber and non-antibacterial crimped staple fiber)> The thermoplastic polyester antibacterial crimped staple fibers and thermoplastic polyester non-antibacterial crimped staple fibers used as the main fibers in the present invention are obtained by subjecting a thermoplastic polyester resin, an antibacterial agent, and, if necessary, additives such as a colorant and a flame retardant to a melt-kneading and spinning process, and by a known manufacturing method of thermoplastic polyester crimped staple fibers consisting of a drawing process, a crimping process, a drying and heat setting process if necessary, and a cutting process. At this time, in order to impart lubricity to the fibers, a fiber lubricant can be used as an additive in each of the spinning, drawing, and crimping processes. There are no particular restrictions on the thermoplastic polyester resin used in the present invention, and any polyester resin can be used regardless of its constituent components as long as it is thermoplastic. The reason for limiting it to thermoplastic polyester resin is that waste polyester can be recycled as long as it is thermoplastic. For example, recycled PET (polyethylene terephthalate) etc. can be used as a fiber raw material. These have become a global trend in recent years with SDGs and ESG investment, and there is an increasing demand for recycling. Recycled PET is widely used as an automotive interior material, but compared with virgin PET derived from petroleum, its quality is inferior and the raw material is unstable, so stable fiber products cannot be obtained, and it is not actually used much in the production of antibacterial fibers containing antibacterial agents.

[0019] (Thermoplastic polyester resin) Polyester is a polycondensate of a polyvalent carboxylic acid (dicarboxylic acid) and a polyalcohol (diol). The polyvalent carboxylic acid (dicarboxylic acid) component constituting such a thermoplastic polyester resin is not particularly limited, and examples include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, bis-(4-carboxyphenyl)sulfone, bis(4-carboxyphenyl)ether, 1,2-bis(4-carboxyphenyl)ethane, 5-sodium sulfoisophthalic acid, diphenyl-p,p'-dicarboxylic acid, p-phenylenediacetic acid, and trans-hexahydroterephthalic acid and their alkyl esters, aryl esters, and ethylene glycol esters.

[0020] On the one hand, the polyalcohol (diol, glycol) component constituting the above-mentioned thermoplastic polyester resin is not particularly limited. For example, ethylene glycol, butylene glycol, 1,2-propylene glycol, 1,4-butanediol, trimethylene glycol, 1,6-hexanediol, 1,4-cyclohexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, bisphenol A, bisphenol S, and their ethylene glycol, polyethylene glycol adducts, diethylene glycol, and polyethylene glycol can be mentioned.

[0021] Furthermore, a condensation-type polyester resin of hydroxycarboxylic acid such as polylactic acids and a known flame-retardant polyester obtained by copolymerizing a flame-retardant component can be used. Depending on the combination of the dicarboxylic acid component and the diol component, the melting point of the resulting polymer (thermoplastic polyester resin or binder fiber) can be in a wide range of 150 to 300 °C, and the low-melting-point polymer can be used as a binder fiber in combination with the high-melting-point polymer. Among these, in particular, as the thermoplastic polyester resin of the present invention, polyethylene terephthalate (melting point 258 °C), polybutylene terephthalate (melting point 243 °C), and polyethylene naphthalate (265 °C), which are used in large quantities and can be obtained at low cost, are preferable. Also, as the low-melting-point polymer, there are a copolymerized polyester composed of polyethylene terephthalate segments with a melting point of 180 °C or lower, a polylactic acid resin, and the like. As the binder fiber, in addition to the thermoplastic polyester fiber, a commonly used polypropylene fiber can be used. The thermoplastic polyester resin may be used alone or in combination of a plurality. The binder fiber is used in an amount of 5 to 20 parts by mass with respect to 100 parts by mass of the main fiber, but this is not included in the main fiber of the present invention. Also, the binder fiber is an optional component that is used as appropriate as needed.

[0022] The number average molecular weight of the above-mentioned thermoplastic polyester resin is not particularly limited, but is preferably from 1,000 to 100,000, more preferably from 5,000 to 50,000. If it is 1,000 or more, yarn formation is possible, and if it is 100,000 or less, an increase in viscosity can be suppressed, so melt spinning is easy. The above number average molecular weight can be measured, for example, by gel permeation chromatography (GPC). Usually, the above number average molecular weight can be substituted with the intrinsic viscosity which is easy to measure. In terms of the intrinsic viscosity, it is 0.05 to 2.53 dL / g, preferably 0.19 to 1.40 dL / g. The intrinsic viscosity can be determined by a method in accordance with JIS K7390 (2003).

[0023] In addition, in the present invention, those discarded after being used as the thermoplastic polyester resin, or scraps generated during the production of industrial products can also be utilized. That is, the thermoplastic polyester resin of the present invention may include recycled polyester resins (among others, recycled polyethylene terephthalate (PET), recycled polybutylene terephthalate (PBT), and recycled polyethylene naphthalate (PEN) resins, and recycled polyethylene terephthalate resin is preferred). In the present invention, the waste polyester resin broadly includes polyester resins other than products, such as used polyester resins, off-specification products before use that are not used as products, etc. Examples of such waste polyester resins include scraps from synthetic fiber manufacturers, film manufacturers, PET bottle manufacturers, polyester polymerization manufacturers, polyester resins below the standard grade, and polyester resins obtained by the container packaging recycling method for general waste. This enables the material recycling of waste materials that would otherwise be discarded or incinerated, contributing to environmental protection and being economically advantageous. Here, with respect to the total amount of 100% by mass of the thermoplastic polyester used in the antibacterial crimped staple fibers according to the present invention and the main fibers composed of antibacterial crimped staple fibers and non-antibacterial crimped staple fibers, it is preferably 20 to 100% by mass of recycled polyester and 80 to 0% by mass of virgin polyester, more preferably 50 to 100% by mass of recycled polyester and 50 to 0% by mass of virgin polyester, and even more preferably 80 to 100% by mass of recycled polyester and 20 to 0% by mass of virgin polyester.

[0024] (Inorganic antibacterial agent) An inorganic antibacterial agent is one in which an antibacterial metal such as silver, copper, or zinc is supported on an inorganic compound. Among the metals, silver has high antibacterial performance. The inorganic antibacterial agent used in the present invention is an inorganic antibacterial agent on which an antibacterial metal component having at least a part of a silver component is supported.

[0025] Examples of the inorganic compound for supporting the silver component include inorganic adsorbents such as activated carbon, activated alumina, and silica gel, zeolite, hydroxyapatite, zirconium phosphate, titanium phosphate, potassium titanate, antimony hydroxide hydrate, bismuth hydroxide hydrate, zirconium hydroxide hydrate, titanium hydroxide hydrate, and inorganic ion exchangers.

[0026] The method for supporting the silver component on these inorganic compounds is not particularly limited. For example, there are methods of supporting by physical adsorption or chemical adsorption, methods of supporting by ion exchange reaction, methods of supporting by a binder, methods of supporting by implanting a metal compound into an inorganic compound, methods of supporting by forming a thin film of a metal compound on the surface of an inorganic compound by a thin film forming method such as vapor deposition, solution precipitation reaction, and sputtering.

[0027] In particular, silver-supported silica gel prepared by the ion exchange method is prepared by bringing silica gel into contact with a silver compound solution, maintaining a predetermined pH by adding an alkali, and bonding silver to the surface silanol groups of the silica gel. The pH range is preferably 4 to 10, more preferably 7 to 10. If it is lower than this, the ion exchange amount of silver is insufficient, and if it is higher than this, the degree of modification of silica becomes too high, which is not suitable. Although the excess alkali can be easily removed by washing, filtration, firing, etc. after preparation, the silver-supported silica gel thus prepared shows alkalinity when dispersed in water. The silica gel has a pH of around 5 in an aqueous slurry, but releases hydrogen ions by ion exchange in a silver nitrate solution and the pH becomes around 4. The silver-supported silica gel antibacterial agent according to the present invention has a pH of 6.5 to 9.0 for an aqueous slurry in which 1 g of the antibacterial agent is dispersed in 100 g of water. By performing ion exchange under an alkali, a large amount of silver component can be firmly captured by the inorganic compound, enhancing the antibacterial performance of the antibacterial agent, enabling effective expression of antibacterial properties with a small addition amount, and enhancing the persistence and durability, which is preferable. For example, as a product, there is NANOXCLEAN (registered trademark) NNXC-AA. An inorganic antibacterial agent containing a silver component supported on alkaline silica is likely to migrate to the fiber surface by blooming in the stretching process, and can exhibit high antibacterial performance even with a small addition amount, which is particularly preferable. Further, by performing the same process under wet conditions, the effect is increased.

[0028] The preferable range of the average particle size of the inorganic antibacterial agent is 0.1 to 10 μm. Here, the average particle size of the inorganic antibacterial agent means the integrated 50% diameter (D50) corresponding to 50% of the integrated distribution obtained from the integrated distribution curve. If it is 0.1 μm or more, aggregation of particles can be prevented, and if it is 10 μm or less, yarn breakage during production, winding stability, and further abrasion resistance can be maintained.

[0029] The content rate of the silver component in the antibacterial crimped staple fiber according to the present invention is 0.5 to 100 mass ppm, preferably 1 to 25 mass ppm, and more preferably 1 to 15 mass ppm. The concentration of the inorganic antibacterial agent carrying the antibacterial metal component, at least a part of which is the silver component, is 0.03 to 5 mass%, preferably 0.05 to 3 mass%, and more preferably 0.05 to 0.85 mass%. If the silver component content rate is 0.5 mass ppm or more, antibacterial properties can be exhibited, and if it is 100 mass ppm or less, discoloration over time can be suppressed. Note that "mass ppm" means ppm (one millionth) of the mass unit. Also, if the concentration of the inorganic antibacterial agent is 0.03 mass% or more, antibacterial properties can be exhibited, and if it is 5 mass% or less, discoloration over time and thread breakage during fiber production can be prevented, the winding of the spun yarn is stable, and furthermore, abrasion resistance can be maintained. In addition, the inorganic antibacterial agent of the present invention can be used as a masterbatch of 5 to 30 mass%. By making it into a masterbatch, the antibacterial agent can be uniformly dispersed in the fiber, and thread breakage during fiber production, winding stability, and furthermore, abrasion resistance can be maintained. The antibacterial property of the crimped staple fiber, in order to be an antibacterial fiber, is 2.0 or more as the antibacterial activity value against Staphylococcus aureus described in "JIS L 1902:2015 Antibacterial Test Method and Antibacterial Effect of Textile Products", and considering blending with non-antibacterial fibers, 2.5 or more is preferable. More preferably, it is 2.5 to 6.0. If the antibacterial activity is 6.0 or less, antibacterial properties can be sufficiently expressed, and the production yield and adverse effects on other physical properties can be reduced.

[0030] Regarding the antibacterial action of silver-based antibacterial agents, both the reactive oxygen generated from the antibacterial agent and the silver ions eluted from the antibacterial agent in the presence of light and water react with microorganisms (bacteria), damaging the microorganisms and suppressing their growth. Viruses are smaller than bacteria but share the common feature of having DNA / RNA and requiring metabolism for activity. Many of the substances used as antibacterial agents can also be used as antiviral agents. Thus, for the expression of antibacterial properties, the concentration of the antibacterial agent on the fiber surface is important, and the migration (blooming) of the antibacterial agent to the surface during the spinning process, stretching process, and drying / heat setting process is important. Hollow fibers can express the antibacterial action more effectively than solid fibers, especially those with a smaller denier per filament. Also, in the case of hollow fibers, the antibacterial agent that has migrated to the inner surface of the hollow can exhibit greater persistence of the antibacterial action during the working process and use, as there is less shedding of the antibacterial agent on the surface.

[0031] (Other additives) As the colorants used in the present invention, known ones such as organic pigments and inorganic pigments can be used. For example, organic pigments including azo-based, anthraquinone-based, quinacridone-based, cyanine-based consisting of cyanine green and cyanine blue, dioxazine-based, phthalocyanine-based consisting of α-type phthalocyanine and β-type phthalocyanine, perinone-based, perylene-based, and polyazo-based; inorganic pigments including titanium yellow, ultramarine, iron oxide, bengala, zinc white, anatase titanium oxide, rutile titanium oxide, and carbon-based consisting of carbon black, graphite, spirit black, channel black, and furnace black can be mentioned, but it is not limited to these. Usually, by appropriately selecting a plurality of suitable pigments from these colorants and mixing them in appropriate amounts, the desired coloring can be applied to the fiber. Also, by directly blending the colorant as a secondary material into the raw material and spinning it to make a raw-colored fiber, light resistance (color deterioration prevention effect) can be imparted to the fiber.

[0032] In addition to the colorant, other additives can be included as long as they do not impair the spinnability and fiber properties. Other additives include inorganic phosphorus-based flame retardants such as red phosphorus and ammonium polyphosphate, and phosphorus-based flame retardants composed of organic phosphorus-based flame retardants such as melamine polyphosphate, phosphate esters, metal organic phosphates, and phosphazenes, flame retardant aids such as antimony oxide and biscumyl, flame retardants such as aluminum oxide, magnesium hydroxide, sodium carbonate, calcium carbonate, and talc, plasticizers such as phthalic esters, phosphate esters, and aliphatic carboxylic acids, stabilizers such as inorganic salts and metal soaps, antioxidants such as alkylphenols and alkylenebisphenols, and ultraviolet absorbers such as salicylic esters, benzotriazoles, and hydroxybenzophenones, and other known additives. Note that the antibacterial crimped staple fiber according to the present invention preferably contains a phosphorus-based flame retardant, and more preferably is a flame retardant fiber exhibiting a flame retardancy with 3 or more flame contact times.

[0033] Regarding the usage amounts of these other additives, based on the total mass of the thermoplastic polyester resin composition (hereinafter also referred to as the raw material resin), which is the raw material of the thermoplastic polyester antibacterial crimped staple fiber or the thermoplastic polyester non-antibacterial crimped staple fiber used as the main fiber, the content of the colorant is 0.01 to 5% by mass, preferably 0.1 to 2% by mass, and the content of the flame retardant is 0.1 to 12% by mass, preferably 1 to 5% by mass. If the colorant is 0.01% by mass or more, it is excellent in that the fiber product can be colored in various colors relatively easily, and if it is 5% by mass or less, it is excellent in that it does not cause deterioration of light resistance such as discoloration. Also, if the content of the flame retardant is 0.1% by mass or more, it is excellent in that sufficient flame retardancy can be imparted, and if it is 12% by mass or less, it is excellent in that the yield can be improved by preventing yarn breakage during spinning. Regarding the usage amounts of the other additives, they can be included within a range that does not impair the spinnability and fiber properties.

[0034] (Spinning, drawing, crimping, drying / heat setting, and cutting processes) The main fiber of the present invention is produced by continuously or discontinuously performing a series of steps such as kneading a thermoplastic polyester resin as a main raw material, an antibacterial agent, and an additive added as necessary, melt spinning, stretching, crimping, and cutting into short fibers. After crimping or after cutting, it includes a drying and heat setting step. These steps can be performed by commonly used methods.

[0035] For example, a raw material resin melt-kneaded by a single-screw or twin-screw extruder is extruded from a nozzle, water is supplied or a spinning finish is supplied as needed, and the yarn is wound up to obtain an undrawn yarn. The cross-sectional shape at that time is arbitrary and may be any of round cross-section fibers, profiled cross-section fibers, hollow fibers, etc. The profiled cross-section (shape) referred to here means a cross-sectional shape other than a round cross-section among solid (a term used for hollow) fiber cross-sections. For the profiled cross-section of solid fibers and the hollow cross-section of hollow fibers, various shapes can be used depending on the intended use. In the case of hollow cross-section fibers, the hollowness of the hollow cross-section is 5 to 40%, preferably 10 to 30%. If the hollowness is 5% or more, it is preferable because it is easy to achieve the weight reduction of the target fiber. If it is 40% or less, the holes are less likely to be crushed or cracked, and a reduction in weight, sound absorption, fiber strength, etc. is prevented, so it is preferable. The hole shape of the nozzle used for manufacturing hollow fibers includes a ring shape, 1C, 2C, 3C, 4C, 5C, etc. corresponding to the number of outside air intake ports. However, in order to maintain the hollowness of the present invention without being crushed by crimping, 1C, 2C, 3C, and 4C are preferable. Here, the ring-shaped hole shape uses a nozzle for manufacturing core-sheath composite fibers, a nozzle in which the sheath is resin and the core is air, 1C uses a normal nozzle, the hole shape is a C shape, and there is one air intake port fixing a part of the ring-shaped hole. 2C has two air intake ports in the ring shape (two C-shaped ones face each other to form a ring), 3C has three, 4C has four, and 5C has five air intake ports. The number of holes is the number of holes per nozzle multiplied by the number of nozzles. The productivity in spinning, that is, the length and amount of fibers per unit time, is determined by the discharge amount, the number of holes, and the winding speed. The number of holes in the nozzle is determined by the scale of the production equipment and is not particularly limited. However, from the viewpoints of productivity, yarn breakage, and quality abnormalities (stick generation) due to fusion, it is preferably 200 to 2000. In the case of hollow fibers, due to yarn breakage and quality abnormalities due to fusion, it is preferably 200 to 1500.

[0036] The melt spinning process is not limited to wet or dry methods, and known methods can be used. Preferably, the dry method is used. From the perspectives of productivity, prevention of thread breakage, and quality abnormalities due to fusion, the take-up speed (winding speed) is 300 to 1000 m / min. From the perspectives of nozzle hole clogging, thread breakage spinning, and quality abnormalities due to fusion, it is preferable to perform melt spinning under the condition that the spinning temperature is 200 to 300 °C, and the conditions should be appropriately changed according to the thread formation state and carried out under optimal conditions. The same applies to the case of hollow fibers, but it is determined by the multiplication of several conditions such as the type of raw materials used, such as resins, antibacterial agents, and other additives, the specifications of the product, the external manufacturing environment such as outside air temperature and humidity, and the characteristics of the manufacturing equipment. Therefore, it is more preferable to conduct preliminary experiments in advance to grasp more optimal conditions and perform melt spinning, which requires more stringent management conditions than the production of solid fibers. In the case of hollow fibers, in particular, cooling at the nozzle exit is important, and it is necessary to control it to obtain an optimal hollow shape. More preferably, the ambient temperature at the nozzle exit is within the range of 20 to 50 °C, and it can be determined by conducting preliminary experiments in advance in combination with other conditions.

[0037] Since the unoriented yarn has insufficient molecular orientation, it is necessary to perform a stretching process at an appropriate temperature below the melting point to align the molecules in the fiber axis direction. The unoriented yarn may be stretched directly in a continuous process, or it may be stretched after being once incorporated into a skein or wound onto a bobbin and then aged. The stretching process may be a single stage or multiple stages of two or more stages. From the viewpoint of ensuring the optimal strength and elongation of the fiber, the stretching ratio is preferably about 1.0 to 6.0. If the stretching ratio is 1.0 or more, sufficient strength can be maintained, and if it is 6.0 or less, sufficient elongation can be maintained, which is excellent. In the case of hollow fibers, from the viewpoint of ensuring the optimal strength, elongation, and hollowness of the fiber, the stretching ratio is 2.0 to 5.0. If it is 2.0 or more, sufficient fiber strength can be maintained, and if it is 5.0 or less, the optimal hollowness can be maintained, which is preferable. Also, there is no problem in using a contact or non-contact heat source in the stretching process. Further, in order to perform stretching smoothly, a fiber lubricant can be applied within a range that does not adversely affect the fiber material. Also, in the process of molecular orientation in the stretching process, additives that are foreign substances to the fiber, such as antibacterial agents and flame retardants, are repelled from the oriented portion of the resin, and a blooming phenomenon occurs, and the additives such as antibacterial agents migrate to the surface. In particular, the silver component of an inorganic antibacterial agent containing a silver component supported on alkaline silica is likely to migrate, and it is further promoted under wet conditions. Therefore, it is particularly preferable that the stretching process is performed in a state where the fiber surface is wet (for example, in a hot water bath). This state is fixed by the crystallization of the resin in the heat treatment process (drying and heat setting process) described later.

[0038] In the crimping process, a known mechanical crimping method that results in a planar, so-called two-dimensional crimp can be used. By setting appropriate conditions, long-term stable shape maintenance and good cardability of the blended fibers can be achieved. For example, in the method using a push-in crimper, appropriate crimp number, crimp ratio, and residual crimp ratio can be imparted to the fibers by adjusting the nip pressure and stuffing pressure and applying steam. A stronger crimp is preferred. Stable crimping can be preferably achieved by setting the nip pressure to 0.05 - 0.85 MPa, particularly 0.10 - 0.55 MPa, and the stuffing pressure to 0.05 - 0.85 MPa, particularly 0.10 - 0.45 MPa. The crimp number, crimp ratio, and residual crimp ratio are determined by delicate adjustment of both. When the nip pressure and stuffing pressure are each 0.05 MPa or more, it is possible to effectively prevent a significant decrease in the crimp number, crimp ratio, and residual crimp ratio. When they are 0.85 MPa or less, it is possible to prevent an increase in the crimp number, crimp ratio, and residual crimp ratio. As a result, it is excellent in that it can effectively prevent an increase in product variation and further stabilize the quality. Regarding the crimp number, crimp ratio, and residual crimp ratio, in order to improve the fiber-to-fiber bonding treatment by carding and needle punching, etc., it is preferable to perform them under the same crimping conditions for both antibacterial fibers and non-antibacterial fibers, or solid fibers, flame-retardant fibers, and hollow fibers.

[0039] The crimp number of the main fibers obtained by the drying and heat setting process described later is 5 - 35 crests / inch, preferably 10 - 25 crests / inch. Within this range, a non-woven fabric or spun yarn with good texture can be obtained without problems in fiber bonding and entanglement. If the crimp number is less than 5 crests / inch, fiber bonding and entanglement are insufficient, and web dropout may occur in the lamination process after passing through the card. Also, if the crimp number exceeds 35 crests / inch, neps are likely to occur, causing a decrease in surface quality.

[0040] The crimp ratio of the staple fibers obtained by the drying and heat setting process described below is 5 to 40%, preferably 10 to 30%, and the residual crimp ratio is 3 to 35%, preferably 7 to 25%. If the values are within these ranges, a nonwoven fabric or spun yarn that balances the carding process passability and surface quality can be obtained. If either the crimp ratio is less than 5% or the residual crimp ratio is less than 3%, the fiber bonding and entanglement are insufficient, and web punching may occur in the lamination process after passing through the card. Also, if the crimp ratio exceeds 40% or the residual crimp ratio exceeds 35%, the cohesive force between the short fibers becomes too strong, leading to easy nep formation and a decrease in surface quality.

[0041] Generally, mechanical crimping (also called two-dimensional crimping or apparent crimping) is used for manufacturing fibers from recycled PET. In the spinning process, when using anisotropic cooling or a spinning method (conjugate spinning) that uses two thermoplastic resins with different heat shrinkage ratios, three-dimensional crimping (also called three-dimensional crimping or latent crimping) occurs, and a light web with a large specific volume suitable for bedding such as futon cotton can be obtained. The crimped staple fibers used in the present invention are fibers with strong crimp obtained by mechanical crimping.

[0042] The fineness (denier per filament) of the main fiber obtained by the drying and heat setting process described below can be determined from the discharge amount (g / min) during spinning, the take-up speed (winding speed) (m / min), the number of holes in the nozzle, and the draw ratio, and can be expressed in decitex (dtex), which is the number of grams per 10,000 m of fiber length. The fineness of the fiber is preferably 1.0 to 10.0 dtex. When the fineness is 1.0 dtex or more, yarn breakage during spinning can be prevented. On the other hand, when the fineness is 10.0 dtex or less, the rigidity of the main fiber can be prevented from becoming excessively strong, and the processability of the fiber is improved. Further, in the present invention, since the antibacterial performance is more excellent as the surface area of the fiber is larger, it is more preferably 1.0 to 7.0 dtex. The denier per filament is determined by the spinning conditions of the fiber, and as the value of the denier per filament, the value obtained by the method of "(1) Denier per filament (decitex; dtex)" described in the column of "A. Measuring method of crimped short fiber" in the Examples section described below shall be adopted. In addition, by measuring the fineness of the fiber with a microscope or the like, the equivalent value of the denier per filament can be calculated from the method of "(2) Equivalent value of denier per filament and hollowness ratio determined from microscopic observation" described in the column of "A. Measuring method of crimped short fiber" in the Examples section.

[0043] Also, the cut length (fiber length) of the main fiber obtained by the drying and heat setting process described below is preferably 5 to 200 mm, more preferably 10 to 80 mm. If the cut length (fiber length) of the main fiber is 5 mm or more, entanglement between the fibers is sufficiently exhibited, and it is excellent in that continuous fiber discharge can be easily achieved by operations such as carding. Also, if the cut length (fiber length) of the main fiber is 200 mm or less, it is excellent in that excessive entanglement of the fibers can be effectively suppressed and uniform carding can be performed.

[0044] Next, in the drying and heat setting process, a heating furnace is used to remove the moisture adhering during stretching. Then, by aging at a temperature above the glass transition temperature and below the melting point of the resin, the crystallization of the resin is promoted, and the fiber strength can be increased. The heat-set long fibers are finally cut into short fibers by a cutting process using a cutting machine and then packaged and bundled. The cut length has been described above. The cutting process may be performed after the drying and heat setting process or after the stretching and crimping process.

[0045] As the fiber lubricant, synthetic lubricating oils such as fatty acid ester type and polyether type, nonionic surfactants such as PEG (polyethylene glycol) type, ester type, and amide type, anionic surfactants such as sulfonate type, phosphate type, and carboxylate type, amphoteric surfactants, nonionic surfactants, etc., which are usually used as fiber lubricants, can be used. The amount of the lubricant adhering to the fiber may be used within a range that does not impair the effects of the present invention and within a range that can effectively exhibit the characteristics and functions as a fiber lubricant. For the fiber obtained by the drying and heat setting process, it is preferably 0.01 to 1.0% by mass, more preferably 0.05 to 0.5% by mass. If the amount of the lubricant adhering to the fiber is within the above range, it is preferable in terms of excellent cardability and punching property.

[0046] <Web and nonwoven fabric> The web and nonwoven fabric can be manufactured by known methods, and specific examples thereof are shown below.

[0047] Manufacture of web (blending and carding processes) For example, the above-mentioned thermoplastic polyester antibacterial crimped short fibers and thermoplastic polyester non-antibacterial crimped short fibers (main fibers) are mixed at a predetermined ratio (mixing process), carded with a carding machine (carding process), and the short fibers are arranged in a certain direction to produce a web. That is, the web used in the nonwoven fabric of the present invention is formed by mixing and carding the main fibers. During carding, due to the wear on the fiber surface, the silver component inside can be exposed on the fiber surface to enhance the antibacterial performance.

[0048] Manufacture of nonwoven fabric Next, the webs are laminated using a cross-lapper and adjusted to a predetermined basis weight. Then, the webs are punched with a needle punch machine (needle punching process step), and the short fibers are entangled with each other (specifically, three-dimensionally entangled and integrated) to strengthen the bond between the fibers, thereby obtaining a non-woven fabric. That is, the non-woven fabric of the present invention is obtained by three-dimensionally entangling and integrating (uniform) webs formed by blending and carding the main fibers with each other to strengthen the bond between the fibers. When the web contains binder fibers, heat treatment can be performed at a temperature equal to or higher than the melting point of the binder fibers (polymers) and equal to or lower than the melting point of the main fibers to obtain a final product with a stable shape.

[0049] The ratio of the crimped short fibers to be blended is 10% to 90% by mass, preferably 20% to 70% by mass, of the antibacterial crimped short fibers with respect to 100% by mass of the total amount of the main fibers, and 90% to 10% by mass, more preferably 70% to 20% by mass, of the non-antibacterial crimped short fibers. If the antibacterial crimped short fibers are less than 10% by mass (the non-antibacterial crimped short fibers exceed 90% by mass), it does not lead to the antibacterial property of the non-woven fabric. If it exceeds 90% by mass (the non-antibacterial crimped short fibers are less than 10% by mass), it leads to an increase in cost due to the antibacterial agent, a decrease in yield, a decrease in mechanical properties, etc., which is not preferable. Also, if the antibacterial crimped short fibers and the non-antibacterial crimped short fibers are within this range, it becomes possible to adjust the color to various colors desired by customers by blending, reduce the number of item numbers of the original fibers, and reduce the cost due to mass production.

[0050] From the viewpoints of preventing skewing, weight reduction, strength, etc. of the non-woven fabric, the number of webs to be laminated is preferably 3 to 10, and the basis weight of the non-woven fabric is preferably 180 to 350 g / m 2 is preferable, 200 to 350 g / m 2 is more preferable, and 200 to 300 g / m 2 is even more preferable. If the basis weight of the non-woven fabric is less than 180 g / m 2 , the basis weight unevenness of the non-woven fabric is large, which causes skewing and deteriorates the surface quality. If it is 350 g / m 2If it exceeds this value, even when using the antibacterial fiber, it is not preferable as it does not lead to weight reduction of the non-woven fabric. As the method for manufacturing the web and non-woven fabric of the present invention, known methods can be used.

[0051] <Fiber processed product> The antibacterial fiber processed product according to the present invention includes bedding, sofas, cushions, fillers such as automotive interior materials, etc. obtained from the above-mentioned web (cotton) of the present invention, non-woven fabrics obtained from the web, and curtains, carpets, uniforms, socks, underwear, etc. obtained from spun yarns.

Examples

[0052] Hereinafter, the present invention will be specifically described with reference to reference examples, comparative reference examples, examples, and comparative examples of the present invention. The measurement methods for each characteristic value are as follows.

[0053] A. Measurement method for crimped staple fiber (1) Denier per filament (dtex) It is a unit representing the thickness of the fiber yarn and is the number of grams per 10,000 m. It was obtained by the following formula from the discharge rate (g / min), winding speed (take-up speed) (m / min), number of holes in the nozzle, and draw ratio during spinning. In the case of hollow fibers, the calculation was made considering the hollowness ratio.

[0054]

Equation

[0055] (2) Denier equivalent value and hollowness ratio obtained from microscopic observation The cross-sectional area (μm 2 ) and hollow area (μm 2 ) of a single fiber were measured with a microscope, and the denier equivalent value was calculated from the arithmetic mean of 10 points assuming the density of PET resin to be 1.38 g / cm 3 , and the hollowness ratio was determined from the ratio of the hollow area to the cross-sectional area of the single fiber using the following formula.

[0056]

Equation

[0057] (3) Cut length (fiber length) The short fiber sample obtained in the cutting process was sampled from two locations, and the length of the short fibers in the natural state (see Figures 2 and 3) was measured. The arithmetic mean value (mm) of a total of 10 measured values, 5 for each sample at each sampling location, was determined.

[0058] (4) Strength and elongation Using a tensile strength and elongation tester (manufactured by Orientec Co., Ltd., model: STA-1150, 2N), measurements were made in accordance with JIS L 1013 (8.5.1). One single fiber was collected from the short fibers, and the sample was attached to the grip of the testing machine in a loosely stretched state. The gripping distance was 20 mm, the initial load was (5.88 mN × decitex × 0.1), and the elongation at that time was designated as C (mm). Measurements were carried out at a tensile speed of 20 mm / min. When the strength at break was A (cN) and the elongation at break was B (mm), the tensile strength and tensile elongation were determined by the following equations. Note that the decitex used in equation (3) is the one obtained by equation (1).

[0059] [Number]

[0060] (5) Crimp test The crimp ratio, residual crimp ratio, and crimp elasticity ratio were measured in accordance with JIS L 1015 (8.12), using a short fiber bundle as the test piece instead of a single fiber. Short fibers with a width of approximately 4 mm and a mass of approximately 0.1 g were collected, accurately weighed using a precision balance to obtain the test piece, and pulled at a speed of 10 mm / min using a universal testing machine (SHIMADZU Autograph, manufactured by Shimadzu Corporation, load cell 50 N), and determined by the following equations.

[0061] [Number]

[0062] Here, A is the length (mm) when an initial load (a load of about 0.001 mN / decitex at the end of the self-weight level) is applied, B is the length (mm) when a load of 4.41 mN × decitex number is applied, and C is the length (mm) when the initial load is applied after leaving it for 1 minute with the load removed.

[0063] The number of crimps was measured in accordance with JIS L 1015 (8.12) using a short fiber bundle as a test piece instead of a single filament. Short fibers with a width of about 4 mm and a mass of about 0.1 g were collected, accurately weighed using a precision balance to obtain a test piece, and pulled at a speed of 10 mm / min using a universal testing machine (SHIMADZU Autograph, manufactured by Shimadzu Corporation, load cell 50 N). The number of peaks (n) at a certain degree of elongation was counted and determined according to the following formula.

[0064]

Number

[0065] Here, A is the length (mm) when an initial load (a load of about 0.001 mN / decitex at the end of the self-weight level) is applied.

[0066] (6) Dry heat shrinkage rate In accordance with JIS L 1015 (8.12, b), one single filament was pulled out one by one from short fibers, a total of 10, a clip was attached to one side, the other side was fixed to cardboard with tape, the cardboard was fixed to the wall, and the single filament length (A mm) was measured with calipers. Then, after drying at 170 °C for 10 minutes, the thread length (B mm) was measured again and determined as the arithmetic mean value of 10 according to the following formula.

[0067]

Number

[0068] (7) Oil content The short fibers were loosened into a cottony state with a hand card and dried at 170 °C for 10 minutes. Next, 2.000 - 2.020 g of cotton was accurately weighed (A), packed into a test tube, immersed in 10 ml of methanol for 45 seconds, and the methanol solution was squeezed out into a pre-weighed cup (B). Then, the methanol solution was evaporated on a hot plate, the weight of the cup (C) was measured, and it was determined from the following formula as the arithmetic mean of five points.

[0069]

Equation

[0070] (8) Antibacterial property The antibacterial property was evaluated in accordance with JIS L 1902: Fiber's Bacterial Liquid Absorption Method. This method is also the test method for the "Antibacterial and Deodorant Processed Fiber Products" and "Bacteriostatic Processed Fiber Products" certification standards of the General Incorporated Foundation Fiber Evaluation Technology Council · SEK Mark. It involves immersing the sample in a bacterial liquid and examining the change in the number of bacteria after a certain period of time.

[0071] Specifically, 0.4 g of the test piece was placed in a vial, 0.2 ml of the test bacterial liquid was dropped, and then the vial was capped. Next, the vial was cultured at 37 °C for 18 - 24 hours, 20 ml of the washing liquid was added to wash out the test bacteria from the test piece, and the viable bacteria count in the washing liquid was measured by the pour plate culture method or the luminescence measurement method. Then, the antibacterial activity value was calculated according to the following formula.

[0072]

Equation

[0073] Here, A is the viable bacteria count after culture of the control sample, B is the viable bacteria count immediately after inoculation of the control sample, C is the viable bacteria count after culture of the test sample, and D is the viable bacteria count immediately after inoculation of the test sample. An antibacterial activity value of 2 or more is determined to have an antibacterial effect.

[0074] B. Measurement method of web (1) Blending condition The antibacterial crimped staple fibers and non-antibacterial crimped staple fibers were opened using a carding machine, and the blending condition was visually confirmed (specifically, visually by comparison with a good / bad sample created based on experience). The good cases were marked with ○, the fairly good cases with △, and the bad cases with ×, as shown in Table 3 below. For those skilled in the art, the quality of the blending can be sufficiently judged only by visual inspection. Also, when repeating the test for this example, instead of the said sample, for example, the web obtained in Example 1 can be used as a good sample, and the web obtained in Comparative Example 1 can be used as a non-good sample to judge the quality of other examples and comparative examples. Also, by adding the webs obtained in other examples and comparative examples to the good sample and the non-good sample, a more accurate sample (large quantity of samples) can be obtained and used for judging the quality of the blending of webs carried out under conditions other than the examples and comparative examples.

[0075] (2) Cardability When coming out of the carding machine, the winding around the cylinder, the generation of scum and nep, and the connection condition of the web were visually evaluated in five grades by comparison with a sample created based on experience. The five-grade evaluation is 5: very good, 4: fairly good, 3: good, 2: bad, 1: very bad, as shown in Table 3 below. For those skilled in the art, the five-grade evaluation of these winding around the cylinder, the generation of scum and nep, and the connection condition of the web can be sufficiently judged only by visual inspection. Also, when repeating the test for this example, instead of the said sample, for example, the web obtained in Example 14 can be used as a sample with an evaluation of 5 (very good). Similarly, the web obtained in Example 13 can be used as a sample with an evaluation of 4 (fairly good), the web obtained in Example 10 can be used as a sample with an evaluation of 3 (good), the web obtained in Example 26 can be used as a sample with an evaluation of 2 (bad), and the web obtained in Comparative Example 6 can be used as a sample with an evaluation of 1 (very bad). By doing so, the webs of other examples and comparative examples can be evaluated (judged) in five grades. Also, by adding the webs obtained in other examples and comparative examples to the five-grade samples, a more accurate sample (large quantity of samples) can be obtained and used for judging the five-grade evaluation of the cardability of webs carried out under conditions other than the examples and comparative examples.

[0076] (3) Web yield The input amount of short fibers into the card machine and the yield of the resulting web were measured, and the amount of waste cotton and the web yield (%) were determined.

[0077] (4) Specific volume, compression ratio, recovery rate The measurements of specific volume, compression ratio, and recovery rate were carried out in accordance with JIS L 1097 (5.2, 5.3 methods). The web was folded with a floor area of 20 cm × 20 cm, and a web test piece adjusted to about 40 g was prepared, and the exact weight (W) was measured. Next, an acrylic plate (20 cm × 20 cm, 267.2 g) was placed on the obtained test piece, a 2 kg weight A was placed for 30 seconds, then this weight A was removed, and it was left standing for 30 seconds. This operation was repeated 3 times. After leaving it standing for 30 seconds with weight A removed, the heights at the four corners were measured, and the arithmetic mean value (h 0 ) was determined, and the specific volume was calculated according to the following formula. This test was carried out on 3 test pieces, and the web specific volume was determined as the arithmetic mean.

[0078]

Equation

[0079] A 4 kg weight B was placed on the test piece whose height had been measured for 30 seconds, the heights at the four corners were measured, and the arithmetic mean value (h 1 ) was determined. Next, after removing weight B and leaving it standing for 3 minutes, the heights at the four corners were measured, and the arithmetic mean value (h 2 ) was determined, and the compression ratio and recovery rate were calculated according to the following formula. This test was carried out on 3 test pieces, and the results of the compression ratio and recovery rate were shown as the arithmetic mean values.

[0080]

Equation

[0081] C. Measurement method of non-woven fabric (1) Actual basis weight The edge of the non-woven fabric was cut into 40 cm × 40 cm vertically and horizontally, and the actual basis weight was determined from the area and weight.

[0082] (2) Thickness (bulkiness) of non-woven fabric The non-woven fabric was cut into test pieces measuring approximately 5 cm × 5 cm in length and width, and in accordance with JIS L 1913 (Method 6.1.1.A), a pressure of 0.5 kPa was applied, and the thickness was measured 10 seconds later. The thickness (mm) of the non-woven fabric was determined as the arithmetic mean value of 10 measurements.

[0083] (3) Scaling property The periphery was surrounded by a cardboard box, a red projector was placed at the bottom, the upper part was covered with a semi-transparent acrylic plate, and a non-woven fabric measuring 40 cm × 40 cm in length and width was placed on it. The scaling property was evaluated by shining red light through it. The non-scaled part was red, and where there was scaling, depending on the degree of scaling, it became less red and the higher the degree of scaling, the thinner (more yellowish) it became. In the black-and-white displayed Figure 1, if there was even a part of the × part (the part surrounded by the solid line near the × mark in the figure; the part with a relatively high degree of scaling and more white display) present, it was evaluated as scaling property ×, if it remained up to the △ part (the part surrounded by the solid line near the △ mark in the figure; the part with a relatively low degree of scaling and slightly white display), it was evaluated as scaling property △, and if it was only the ○ part (the part of the ○ mark surrounded by the solid line in the figure; the part without scaling or with almost no scaling and relatively black (or gray) display), it was evaluated as scaling property ○. In addition, the part with scaling was cut into a size of 1 cm × 1 cm in length and width, and the part with the lowest transmittance of scaling property ○ was set as a transmittance of 0%. By image analysis processing, the average transmittance within 1 cm × 1 cm was determined as a quantitative standard for the scaling property. Scaling property ○: Transmittance of 0% or more and 30% or less, Scaling property △: Transmittance exceeding 30% and 60% or less, Scaling property ×: Transmittance exceeding 60% and 100% or less.

[0084] (4) Strength and elongation of non-woven fabric The measurement of strength and elongation was carried out using a universal testing machine (SHIMADZU Autograph, manufactured by Shimadzu Corporation) in accordance with JIS L 1913 (6.1.2A, Method 6.3). The non-woven fabric was cut into widths of 40 mm and lengths of approximately 200 mm in the longitudinal direction (needle punching direction) and the transverse direction (perpendicular to the needle punching direction), respectively, and five test pieces were prepared for each direction. Next, the test pieces were attached to the testing machine at 150 ± 1 mm with an initial load (the degree to which the test piece does not sag when pulled by hand). Then, a load was applied at a tensile speed of 100 mm / min until the test piece was cut, and the strength (N / mm 2 ) and elongation (%) at the maximum load were measured, and the strength and elongation of the non-woven fabric were calculated as the arithmetic mean values of the five test pieces.

[0085] (5) Antibacterial property The antibacterial property was carried out in accordance with JIS L 1902: Fiber Bacterial Liquid Absorption Method, similar to the above crimped staple fiber.

[0086] (6) Flame retardancy The flame retardancy of the crimped staple fiber was carried out in accordance with the 45° combustion test: JIS L 1091 D method (flame contact test), the combustion test method for textile products (Japanese Industrial Standard). The test piece should be 100 mm in length and 1 g in mass. Insert the test piece into the center of the test piece support coil and maintain a 45° inclination. The flame of the burner (flame height 45 mm) contacts the lowest end of the test piece in the test piece support coil, and heat is applied until the test piece melts and the combustion extinguishes. Furthermore, the lowest end of the remaining test piece is contacted with the flame again. This operation is repeated continuously until the test piece melts and burns up to a position 90 mm from the lower end of the test piece. The test result represents the one with the fewest number of flame contacts during five measurements. If the number of flame contacts is 3 or more, it is determined to have flame retardancy.

[0087] [Examples 1 to 8, Comparative Examples 1 to 4, and Reference Example 1 (Manufacture of Crimped Staple Fiber)] Virgin PET (intrinsic viscosity 0.65) of polyethylene terephthalate (PET) manufactured by Mitsubishi Chemical Corporation, trade name "NOVAPEX", or recycled PET adjusted to an intrinsic viscosity of 0.65 from PET scraps, PET end materials, and waste PET bottles was used as the main raw material. Using the silver-based antibacterial agent, pigment, and flame retardant shown in Table 1, it was kneaded with an extruder, and then melt-spun at 230 to 285 °C under the spinning setting conditions shown in Table 1, stretched at the draw ratio shown in Table 1 in a hot water bath, and then using a push-in crimper, the nip pressure and stuffing pressure were adjusted to impart mechanical crimping or latent crimping. After drying and heat setting, it was cut with a rotary cutter (cutting machine) to obtain crimped staple fibers having the silver concentration (calculated value), appearance, shape, and physical properties shown in Table 2. Each shape and performance was determined by the method described above.

[0088]

Table 1

[0089]

Table 2

[0090] Regarding the raw material PET, in Examples 1 to 5, 7, and 8, and Comparative Examples 1 to 4, the recycled PET was used alone. In Example 6, an equal-mass mixture of the recycled PET and the virgin PET was used, and in Reference Example 1, the virgin PET was used alone. Among the results shown in Table 2, Reference Example 1 using the virgin PET alone showed excellent results in terms of strength and elongation.

[0091] Regarding the antibacterial agents, in Examples 1 to 6 and 8 and Comparative Examples 1 and Reference Example 1, the silver-based antibacterial agent NNXC AA manufactured by NANOX (Nanox), in which the silver component is supported on silica (silver concentration: 0.24% by mass determined by a fluorescence X-ray analyzer (SQX method) equipped with a standardless analysis function), was used. In Example 7, the silver-based antibacterial agent Novaron AGT330 manufactured by Toagosei Co., Ltd., in which the silver component is supported on zirconium phosphate (silver concentration: 2.7% by mass determined by a fluorescence X-ray analyzer (SQX method) equipped with a standardless analysis function), was used. In the antibacterial test, all except Comparative Examples 2 to 4 were 2 or more, and a determination of having an antibacterial action was obtained. Among the antibacterial agents, using the silver-based antibacterial agent NNXC AA manufactured by Nanox supported on silica resulted in better results despite the lower addition amount compared to the silver-based antibacterial agent Novaron AGT330 manufactured by Toagosei Co., Ltd. supported on zirconium phosphate.

[0092] Regarding the pigments, in Examples 1 to 3 and 5 to 8 and Comparative Examples 1, 2, 4 and Reference Example 1, no pigment was added, and the crimped staple fibers were light brown when recycled PET was used and cloudy transparent when virgin PET was used. In Examples 4 and Comparative Example 3, a carbon-based black pigment (used as a masterbatch: carbon-based black pigment content 30%) was used, and the crimped staple fibers became black. In Examples 8 and Comparative Example 4, as a result of using an inorganic phosphorus-based flame retardant (used as a masterbatch: phosphorus concentration 20%) as the flame retardant, values of 3 or more were obtained in the 45° combustion test, resulting in a determination of having flame retardancy.

[0093] Regarding the shape of the nozzles during spinning, in Examples 1 to 4 and 6 to 8 and Comparative Examples 1 to 4 and Reference Example 1, a round cross-section was used, and at that time, crimped staple fibers were obtained. In Example 5, a nozzle with a 1C shape was used, and crimped hollow staple fibers with a hollowness of 16% were obtained.

[0094] As the oil agent, a fiber oil agent for nonwoven fabric (a mixture of PEG type and ester type nonionic surfactants and phosphate type and carboxylate type anionic surfactants) was used. Note that as long as the oil agent used in this example or the like is a commonly used fiber oil agent for nonwoven fabric, it will not affect the following web and nonwoven fabric performance evaluation contents, so it may be replaced with other fiber oil agents for nonwoven fabric.

[0095] In addition, the short fibers with mechanical crimp obtained by normal cooling in Examples 1 to 8, Comparative Examples 2 to 4, and Reference Example 1 showed a two-dimensional zigzag crimp shape as shown in Figure 2, and the short fibers with latent crimp obtained by anisotropic cooling in Comparative Example 1 showed a three-dimensional solid crimp shape as shown in Figure 3.

[0096] [Examples 9 to 24 and Comparative Example 5, and Reference Examples 2 and 3 (manufacture of web)] The antibacterial crimped short fibers obtained in Example 1 and the non-antibacterial crimped short fibers obtained in Comparative Example 2 were weighed in the required amounts so as to have the basis weight of the nonwoven fabric of 200 g / cm 2 and the mixing ratios shown in Table 3, pre-opened (mixed) and then the input amounts shown in Table 3 were determined, passed through a carding machine, and opened (carded) three times while changing the direction to produce a web. The waste fiber at this time was weighed to obtain the yield, the mixing state and cardability were observed, and the specific volume, compression ratio and recovery ratio were obtained, which are shown in Table 3 as Examples 9 and 10.

[0097] Also, instead of the short fibers of Example 1, the short fibers of any one of Examples 2 and 3 and Examples 5 to 8 were used, and a web was produced in the same manner as in Example 9, and the results are shown in Table 3 as Examples 11 to 15, 17, 18, 20, 22, 23 and 24.

[0098] Furthermore, instead of the short fibers of Example 1, the short fibers of Example 2 or 4 were used, and instead of the short fibers of Comparative Example 2, either the short fibers of Comparative Example 2 were not used or the short fibers of Comparative Example 3 or 4 were used, and a web was produced in the same manner as in Example 9, and the results are shown in Table 3 as Examples 16, 19 and 21.

[0099] On the other hand, instead of the staple fibers of Example 1, either the staple fibers of Example 1 were not used or the staple fibers of Comparative Example 1 were used, and a web was produced in the same manner as in Example 9. The results are shown in Table 3 as Reference Example 2 and Comparative Example 5. Further, instead of the staple fibers of Example 1, the staple fibers of Reference Example 1 were used, and a web was produced in the same manner as in Example 9. The results are shown in Table 3 as Reference Example 3.

[0100]

Table 3

[0101] From the results in Table 3, it can be seen that the webs obtained using the antibacterial crimped staple fibers with mechanical crimp (Examples 9 to 24) are superior in cardability, blending condition, and web yield compared to the webs obtained using the antibacterial crimped staple fibers with latent crimp (Comparative Example 5). For the web (Comparative Example 5) obtained using the antibacterial crimped staple fibers with latent crimp, which is often used as futon cotton, a high non-volume value was obtained, but the recovery rate was low.

[0102] When an inorganic phosphorus compound was used as the flame retardant (Examples 21 and 24), the results were inferior in cardability, blending condition, and web yield compared to the case where no inorganic phosphorus compound was used. The web obtained using the antibacterial hollow crimped staple fibers (Example 20) showed almost the same performance as the web obtained using the antibacterial solid crimped staple fibers, except for the compression rate.

[0103] Even when changing the concentration of the antibacterial agent in the antibacterial crimped staple fibers (Examples 1 to 3) and the mixing ratio of the antibacterial crimped staple fibers and the non-antibacterial staple fibers (comparison of Examples 9, 10, and Reference Example 2, comparison of Examples 12, 15, and 16, and comparison of Examples 17 and 18), the influence on the physical properties was small. It was found that the cardability improved when increasing the target basis weight of the non-woven fabric (Examples 11 to 14).

[0104] Also, there were no significant differences in the short fiber production between the webs obtained using virgin PET (Examples 22 and Reference Example 3) and the webs obtained using recycled PET. Example 16 with only antibacterial short fibers had performance comparable to that of Reference Example 2 and Example 15 with a 50 / 50 blend ratio. Regarding the antibacterial performance of the web, since the test specimens became considerably bulky compared to the short fibers and non-woven fabrics, antibacterial tests were not conducted, but it is presumed that the antibacterial performance is comparable to that of the non-woven fabrics.

[0105] [Examples 25 to 40, Comparative Example 6, and Reference Examples 4 and 5 (Manufacture of Non-Woven Fabrics)] The webs obtained according to Table 3 were punched using a needle loom (model NL-380) under the conditions of a working width of 380 mm, a stroke of 75 mm, a stroke number of 190 strokes / min, a web pitch width of 4 mm, 750 needles, a needle pitch of 12.5 mm horizontally, 30 rows of pitch, 10.0 mm vertically, and 25 rows of pitch to produce non-woven fabrics. The antibacterial property, flame retardancy, scab resistance, actual basis weight, thickness, longitudinal / transverse strength, and longitudinal / transverse elongation of the non-woven fabrics were measured, and the results are shown in Table 4 as Examples 25 to 40, Comparative Example 6, and Reference Examples 4 and 5.

[0106]

Table 4

[0107] From the results in Table 4, it can be seen that the non-woven fabrics obtained using antibacterial crimped short fibers with mechanical crimp (Examples 25 to 40) are superior in antibacterial property, scab resistance, strength, and elongation compared to the non-woven fabrics obtained using antibacterial crimped short fibers with latent crimp (Comparative Example 6), except for the strength of Example 40. Also, the non-woven fabrics obtained from antibacterial crimped short fibers with mechanical crimp have slightly lower elongation compared to the non-woven fabrics obtained from non-antibacterial crimped short fibers with mechanical crimp (comparison between Example 32 and Reference Example 4).

[0108] In addition, a nonwoven fabric obtained by blending antibacterial crimped staple fibers with mechanical crimps and non-antibacterial crimped staple fibers with mechanical crimps has a basis weight of 200 g / cm 2 or more, it can be seen that the skeinability is improved, and the strength and elongation increase as the basis weight increases (Examples 27 to 30).

[0109] A nonwoven fabric obtained by blending hollow antibacterial crimped staple fibers and solid non-antibacterial crimped staple fibers is superior in antibacterial property and elongation compared to the case where solid antibacterial crimped staple fibers are used (comparison between Example 36 and Example 28). It was found that the original antibacterial crimped staple fiber nonwoven fabric (Example 35) and the flame-retardant antibacterial crimped staple fiber nonwoven fabric (Examples 37 and 40) obtained by adding pigments and flame retardants during melt spinning can impart coloring and flame retardancy, respectively, without significantly affecting other physical properties.

[0110] When virgin PET was used instead of recycled PET as the raw material, slightly better results in terms of strength and elongation were obtained compared to those containing recycled PET (comparison between Example 38 and Reference Example 5). Also, as the silver-based antibacterial agent, the silica-supported one (Examples 25 to 38 and Example 40) showed superior antibacterial performance compared to the zirconium phosphate-supported one (Example 39).

Claims

1. A method for producing antibacterial crimped staple fibers, comprising a melt-kneading spinning step of a resin raw material containing a thermoplastic polyester including recycled polyester and an inorganic antibacterial agent in which an antibacterial metal component, at least a part of which is a silver component, is supported on an inorganic compound, a drawing step performed in a state in which the fiber surface is wet, a crimping step, and a cutting step, The antibacterial crimped staple fibers have an antibacterial activity value of 2.5 or more, a fiber thickness of 1.0 to 10.0 decitex, and are two-dimensionally mechanically crimped, and the number of crimps in the mechanical crimp is 5 to 35 crimps / inch, the crimp rate is 5 to 40%, and the residual crimp rate is 3 to 35%.

2. A method for producing antibacterial crimped staple fibers as described in claim 1, wherein the content of the silver component in the antibacterial crimped staple fibers is 1 to 25 ppm by mass.

3. A method for producing antibacterial crimped staple fibers as described in claim 1, wherein the antibacterial crimped staple fibers are hollow fibers having a hollow ratio of 5 to 40%.

4. A method for producing antibacterial crimped staple fibers as described in claim 1, wherein the antibacterial crimped staple fibers contain a phosphorus-based flame retardant and exhibit flame retardancy when exposed to flame three or more times.

5. A method for producing antibacterial crimped staple fibers as described in claim 1, wherein in the antibacterial crimped staple fibers, the recycled polyester accounts for 20 to 100 mass% and the virgin polyester accounts for 80 to 0 mass% relative to 100 mass% of the total amount of the thermoplastic polyester.

6. A method for producing antibacterial crimped staple fibers as described in claim 1, wherein in the antibacterial crimped staple fibers, the inorganic antibacterial agent contains a silver component supported on alkaline silica as an inorganic compound, and the concentration of the inorganic antibacterial agent is 0.05 to 0.85 mass%.

7. antibacterial crimped staple fibers having a fiber thickness of 1.0 to 10.0 decitex are obtained by a production method including a melt-kneading spinning process of a resin raw material containing a thermoplastic polyester including recycled polyester and an inorganic antibacterial agent in which an antibacterial metal component, at least a part of which is a silver component, is supported on an inorganic compound, a drawing process performed in a wet state of the fiber surface, a crimping process, and a cutting process; A method for producing a web, comprising blending and carding the antibacterial crimped staple fibers and non-antibacterial crimped staple fibers as subject fibers in a mass ratio of 10 to 90 mass% of the antibacterial crimped staple fibers and 90 to 10 mass% of the non-antibacterial crimped staple fibers relative to 100 mass% of the total amount of the subject fibers, In the web, the subject fibers are two-dimensionally mechanically crimped, the number of crimps of the mechanical crimps is 5 to 35 crimps per inch, the crimp rate is 5 to 40%, the residual crimp rate is 3 to 35%, and the antibacterial activity value is 2.0 or more.

8. A method for manufacturing a web as described in claim 7, wherein the content of the silver component in the web is 0.5 to 15 ppm by mass.

9. The method for producing a web according to claim 7, wherein the antibacterial crimped fibers are hollow fibers having a hollow ratio of 5 to 40%.

10. The method for producing a web according to claim 7, wherein the antibacterial crimped staple fiber is a flame-retardant fiber that contains a phosphorus-based flame retardant and exhibits flame resistance when exposed to flame three or more times.

11. The method for producing a web according to claim 7, wherein the recycled polyester is 20 to 100 mass% and the virgin polyester is 80 to 0 mass% relative to 100 mass% of the total amount of the thermoplastic polyester used in the subject fiber.

12. 8. The method for producing a web according to claim 7, wherein the inorganic antibacterial agent of the antibacterial crimped staple fibers is an inorganic antibacterial agent containing a silver component supported on alkaline silica as an inorganic compound, and the concentration of the inorganic antibacterial agent in the web is 0.05 to 0.085 mass%.

13. antibacterial crimped staple fibers having a fiber thickness of 1.0 to 10.0 decitex are obtained by a production method including a melt-kneading spinning process of a resin raw material containing a thermoplastic polyester including recycled polyester and an inorganic antibacterial agent in which an antibacterial metal component, at least a part of which is a silver component, is supported on an inorganic compound, a drawing process performed in a wet state of the fiber surface, a crimping process, and a cutting process; a production method including blending and carding the antibacterial crimped staple fibers and non-antibacterial crimped staple fibers as subject fibers in a mass ratio of 10 to 90 mass% of the antibacterial crimped staple fibers and 90 to 10 mass% of the non-antibacterial crimped staple fibers relative to 100 mass% of the total amount of the subject fibers, thereby obtaining a web in which the crimp of the subject fibers is two-dimensional mechanical crimp, the number of crimps of the mechanical crimp is 5 to 35 crimps / inch, the crimp percentage is 5 to 40%, and the residual crimp percentage is 3 to 35%, and strengthening bonds between fibers of the web, comprising: The nonwoven fabric has a basis weight of 180 to 350 g / m ２ and further having an antibacterial activity value of 2.0 or more.

14. A method for producing a nonwoven fabric as described in claim 13, wherein the silver content in the nonwoven fabric is 0.5 to 15 ppm by mass.

15. The method for producing a nonwoven fabric according to claim 13, wherein the antibacterial crimped staple fibers are hollow fibers having a hollow ratio of 5 to 40%.

16. The method for producing a nonwoven fabric according to claim 13, wherein the antibacterial crimped staple fiber is a flame-retardant fiber that contains a phosphorus-based flame retardant and exhibits flame resistance when exposed to flame three or more times.

17. The method for producing a nonwoven fabric according to claim 13, wherein the recycled polyester is 20 to 100 mass% and the virgin polyester is 80 to 0 mass% relative to 100 mass% of the total amount of the thermoplastic polyester used in the subject fiber.

18. The method for producing a nonwoven fabric according to claim 13, wherein the inorganic antibacterial agent is an inorganic antibacterial agent containing a silver component supported on alkaline silica as an inorganic compound, and a concentration of the inorganic antibacterial agent in the nonwoven fabric is 0.05 to 0.085 mass%.

19. A method for producing an antibacterial fiber processed product, comprising producing an antibacterial crimped staple fiber by the production method according to any one of claims 1 to 6, producing a web by the production method according to any one of claims 7 to 12, or producing a nonwoven fabric by the production method according to any one of claims 13 to 18.

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