JP2018109245A - Fiber structure having excellent antibacterial performance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fiber structure having effects of excellent antibacterial properties and the like, its effects being excellent in washing durability and being friendly to human bodies, organisms, and the environment, and also having a flexible touch feeling.SOLUTION: A fiber structure of this invention comprises nanofiber which is adhered on the surface of the fiber structure in a mesh-like form, where the width of nanofiber is 4-100 nm and its length is 100-2000 nm, and the number of the nanofiber adhered is 25 or more per unit surface area 1 μmof the fiber structure.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a fiber structure composed of cellulosic fibers, synthetic fibers, or protein fibers having excellent antibacterial performance. More specifically, the present invention is composed of cellulose fibers, synthetic fibers, and protein fibers such as silk and hair that have excellent antibacterial performance, and that the performance is sustained, and that do not interfere with the human body, organism, environment, etc. The present invention relates to an antibacterial fiber structure.

In recent years, consumer awareness and hygiene awareness about hygiene has increased. Cellulosic fibers such as cotton and synthetic fibers such as nylon fibers are often used in clothes such as underwear that directly touch the skin. For this reason, there is a strong demand for fiber structures having antibacterial properties. Needless to say, high antibacterial properties are strongly desired for various fiber structures, particularly in the medical field.
It is not easy to give cellulosic fibers, synthetic fibers, and protein fibers with antibacterial properties that are safe for the human body and durable. When using an antibacterial agent such as ammonium salt, the fiber structure has poor antibacterial properties that are gentle to the human body and have satisfactory antibacterial properties, such as poor skin durability and sensitive skin. The body is not obtained.
Furthermore, in the case of diphenyl ether antibacterial agents and the like, there have been reports of cases where carcinogen dioxins are generated during the incineration of processed fibers, and there are environmental countermeasure issues.
As an antibacterial agent that shows strong antibacterial properties against resistant bacteria and does not generate carcinogens, inorganic compounds in which a metal such as silver, copper or zinc is supported on zeolite are kneaded into the fiber polymer. However, it is necessary to use a considerably large amount in order to exert a desired antibacterial effect. However, when the amount used is increased, there is a problem of causing discoloration or alteration due to oxidization with time. That is, even with this technology, a fiber structure having high stability and safety in products and excellent antibacterial performance has not been obtained.

Patent Document 1 below proposes a processing method using deacetylated chitin (chitosan) which is a natural substance and high safety as an antibacterial agent component. However, a binder resin and a cross-linking agent are used for fixing to the fiber surface, and there remain problems in safety to the human body, the texture is hard, and skin irritation is strong. In addition, there is an important problem that the antibacterial effect inherent in chitosan is suppressed by the binder and the crosslinking agent.
Patent Document 2 below proposes a chitosan-containing cellulose fiber that spins a stock solution in which chitosan is dissolved in a rhodanate aqueous solution together with cellulose. However, since chitosan is present inside the fiber, the amount of chitosan exposed on the surface of the fiber structure in direct contact with the bacteria is extremely small, and the antibacterial property of the contained chitosan was not sufficiently exhibited.
Patent Document 3 below proposes a chitin chitosan viscose fiber in which chitin having a particle size of 4 mm or less is dissolved in a viscose stock solution and is spun by the viscose method. However, as in Patent Document 2, chitin chitosan is present inside the viscose fiber, so that the antibacterial effect is low.
Now, a technique of nano-materializing the material to increase the surface area and significantly improving the effect of the material can be considered. The same applies to antibacterial agents.
Patent Document 4 proposes a method of dispersing chitin nanofibers obtained by nanonization in rayon. The chitin nanofibers are superior in antibacterial properties compared to general chitin fibers whose diameter is not nano-size, but in this case as well, the antibacterial properties were low because most of the chitin nanofibers were present inside the fibers.
In this way, so far, it is derived from natural substances, is highly safe, is gentle to the human body and the environment, has a soft texture, low skin irritation and excellent antibacterial performance, and also has antibacterial performance. A fiber structure excellent in durability was not obtained.

JP-A-4-257301 Japanese Patent Application Laid-Open No. 11-1000071 Japanese Patent No. 2822174 Japanese Patent Application Laid-Open No. 2006-74989

  The problem to be solved by the present invention is that a nanofiber having a specific excellent effect such as antibacterial properties is not used for a structure composed of cellulosic fiber, synthetic fiber or protein fiber without using a binder resin or a crosslinking agent. In addition, by directly and firmly adhering to the surface of the structure, a fiber structure that has excellent antibacterial properties, has excellent washing durability and has a soft texture, and is also friendly to the human body, organisms and the environment. Is to provide.

The inventor diligently studied to solve the above problems and repeated experiments. As a result, by preparing a nanofiber dispersion in which nanofibers with specific functional groups are sufficiently dispersed under optimal conditions, the surface of a structure composed of cellulosic fibers, synthetic fibers, or protein fibers can be obtained. The nanofibers can be directly attached in the form of a mesh, and the present invention has been completed.
That is, the present invention is as follows.
[1] There are 25 or more nanofibers having a length of 4 to 100 nm and a length of 100 to 2000 nm on the surface of a fiber structure made of cellulose fiber, synthetic fiber, or protein fiber, per 1 μm ² of the surface area of the structure, A fiber structure characterized by being fixed to the surface of the structure.
[2] The fiber structure according to [1], wherein the number of entanglements of the plurality of nanofibers is 20 or more.
[3] The fiber structure according to [1], wherein the nanofiber is made of a polysaccharide.
[4] The fiber structure according to [2], wherein the nanofiber is made of a polysaccharide having an acetylamino group.

  The fiber structure of the present invention is a structure composed of cellulosic fibers, synthetic fibers, or protein fibers, and has excellent antibacterial properties by directly attaching nanofibers to the surface thereof in a network form. The fiber structure has excellent washing durability, is gentle to the human body, living organisms and the environment, and has a supple texture.

Fig.1 (a) is a figure which shows the negative ion spectrum of Example 1 as an example of TOF-SIMS analysis. FIG.1 (b) is a figure which shows the negative ion spectrum of Example 1 as an example of TOF-SIMS analysis. 2A and 2B are diagrams showing scanning electron micrographs of Example 1. FIG.

Hereinafter, a mode for carrying out the present invention (hereinafter referred to as “embodiment”) will be described in detail. In addition, this invention is not limited to the following embodiment, It can implement by changing variously within the range of the summary.
In the fiber structure of this embodiment, nanofibers having a width of 4 to 100 nm and a length of 100 to 2000 nm are formed on the surface of a fiber structure made of cellulose fiber, synthetic fiber, or protein fiber, and the surface area of the structure is 1 μm ^2. The fiber structure is characterized in that 25 or more are fixed in a mesh shape.

Cellulosic fibers include natural cellulose fibers such as cotton and hemp, regenerated cellulose fibers such as viscose rayon, copper ammonia rayon and polynosic rayon, and lyocell, tencel by solvent spinning, and acetate fibers that are semi-synthetic fibers. Say. Regenerated cellulose fibers can be preferably used. Among them, when using cupra obtained by the copper ammonia method (Bemberg (registered trademark) manufactured by Asahi Kasei Co., Ltd.), the uneven porous structure existing on the fiber surface improves the adhesion of the nanofibers. This is preferable because the effect is most prominent. In addition, regenerated cellulose has low physical and chemical irritation when it comes into contact with the skin, and is highly preferred for applications that come into contact with the skin. The fiber structure of the present invention preferably contains 25% or more of regenerated cellulose, more preferably 45% or more, and most preferably 70 to 100% of regenerated cellulose.
Examples of the synthetic fiber include polyester fiber, polyamide, polyethylene, polypropylene, polyacrylonitrile, polyurethane, polylactic acid, and the like.
Examples of protein fibers include animal hair fibers such as silk, wool, cashmere, mohair, and vicuuna.
The fiber diameter is not particularly limited, but is preferably a fiber having a total fineness of 20 to 300 dtex. The single fiber fineness is preferably 0.01 to 3.0 dtex in terms of texture and low physical irritation to skin, and more preferably 0.01 to 1.7 dtex.
Furthermore, the cross-sectional shape is preferably a flat shape such as an L-shaped or W-shaped cross section, because the bending rigidity of the fiber is low and a supple texture is easily obtained, and the specific surface area is large and the amount of nanofibers fixed can be easily increased.
The form of the fiber may be long fiber or short fiber, and may be uniform or thick in the length direction. And, as a thread-like form in which the fiber is processed, sweet twisted yarn to strong twisted yarn, false twisted yarn, air injection processed yarn, indented yarn, knitted knitted yarn, etc., ring spun yarn, open end spun yarn, Examples include spun yarn such as air jet fine spinning.
Examples of the fiber structure include knitted fabrics, woven fabrics, nonwoven fabrics, and composites (for example, laminates) thereof.
Examples of yarn forms when mixing different types of fibers include blends (blends, fleece blends, sliver blends, core yarns, silospans, silofills, hollow spindles, etc.), entangled blends, twists, design twists, Covering (single, double), composite false twist (simultaneous false twist, pre-twist false false twist), elongation difference false twist, phase difference, post-mixing after post-mixing, 2-feed (simultaneous feed and feed difference) air injection processing The mixed form by etc. is mentioned.
As a specific example, there is a so-called on-machine mixed article, and there is a knitted fabric in which other bare yarns or coated yarns are mixed and mixed with cellulose fibers and other fibers on the machine at the time of weaving or weaving. .
In the present invention, the mixed form of fibers of different types is not limited to the above, and it is sufficient that the fibers are mixed.

Although it does not specifically limit as a synthetic fiber, For example, the fiber which consists of polyester, polyamide, polyacrylonitrile, a polyurethane, or these copolymers is mentioned, Especially, a polyester and a polyamide fiber are suitable.
The form of the synthetic fiber may be long fiber or short fiber, and may be uniform or thick in the length direction, and round, triangular, L-shaped, T-shaped, Y-shaped, W-shaped, A polygonal shape such as an M shape, an eight-leaf shape, a flat shape, or a dogbone shape, a multi-leaf shape, a hollow shape, or an indefinite shape may be used. Among them, a modified cross-sectional shape having one or more recesses is preferable because the washing durability of the nanofibers fixed is enhanced and a supple texture is easily obtained.
Synthetic fibers are processed in the form of ring spun yarn, open-end spun yarn, air-jet spun yarn, etc., sweet-twisted yarn, high-twisted yarn, false twisted yarn, air-injected yarn, indented yarn And knit and knitted yarns.
Examples of fabric forms include knitted fabrics, woven fabrics, non-woven fabrics, and composite fabrics thereof (for example, laminated fabrics).
In addition, examples of the form of the yarn when a plurality of types of synthetic fibers are used are blended (mixed cotton, fleece blended, sliver blended, core yarn, silo span, silofill, hollow spindle, etc.), entangled blended fiber, twisted yarn, Design twisted yarn, covering (single, double), composite false twist (simultaneous false twist, pre-twist false false twist), elongation difference false twist, phase difference, post-mixing after false twisting, 2 feeds (simultaneous feed and feed difference) The mixed form by air injection processing etc. is mentioned.
The synthetic fiber of the present embodiment is not particularly limited, but the single yarn decitex is preferably 0.01 to 3 dtex, more preferably 0.05 to 1.5 dtex, and the total dtex is 20 to 250 dtex. Is preferred.
The synthetic fiber of this embodiment may contain surfactants such as titanium oxide and alkylbenzene sulfonate, conventionally known antioxidants, anti-coloring agents, anti-lighting agents, antistatic agents, alkali metals, etc. It can be produced by a conventionally known method.

The fiber structure of the present invention is characterized in that 25 or more nanofibers having a width of 4 to 100 nm and a length of 100 to 2000 nm are fixed on the surface in a network shape per 1 μm ² of the surface area of the structure. .
The network shape means a state in which nanofibers intersect each other, and refers to a case where there are 20 or more intersections per surface area of 1 μm ² . It is preferable that the number is 30 or more, because the fixing property is increased, and more preferably 60 or more.
When the nanofibers cover the fiber surface in a mesh shape, the number of nanofibers exposed on the surface is dramatically increased as compared with the conventional method of kneading into fibers. Therefore, the functional effect obtained is also overwhelmingly high. For example, when polysaccharide nanofibers are used, compared to the case where equal amounts of nanofibers are kneaded and mixed, the surface of the nanofibers exposed on the surface is about 1000 times larger in our observation when the surface is covered with a network. Knows you will reach

The nanofiber referred to in the present invention has a diameter of 100 nm or less. It is more preferable that the thickness is 4 to 60 nm, and it is more preferable that the thickness is 4 to 20 nm.
The length is preferably from 100 to 2000 nm, but preferably from 200 to 1000 nm, more preferably from 270 to 800 nm, since the dispersion state of the nanofibers is good and a uniform network is easily formed. When the length is shorter than 100 nm, the adhesiveness is low and the washing durability is also low. When it is longer than 2000 nm, it is difficult to form a uniform mesh shape.

Nanofibers include cellulose nanofibers, chitin nanofibers, chitin nanofibers whose surface is chitosan-modified, chitosan nanofibers whose surface has been modified and insolubilized, and those mixed in an appropriate ratio. Is preferable because it is easy to fix to the fiber, but is not limited to polysaccharides.
It is preferable that the polysaccharide nanofibers are chitin nanofibers having an acetylamino group, and surface chitosanized chitin nanofibers with a part of the surface being deacetylated, since particularly excellent antibacterial properties are exhibited.
Chitin nanofibers are made of chitin-containing organism-derived materials. For example, as chitin nanofibers obtained by methods such as JP 2010-1830309 A and JP 5186694 A or commercially available products, for example, Co., Ltd. BiNFi-s (Binphis) manufactured by Sugino Machine and the like can be mentioned.
In the present invention, it is a preferred embodiment to mix and fix different nanofibers. Another preferred embodiment is to laminate and fix different nanofibers.
For example, the case where a chitin nanofiber and a cellulose nanofiber are mixed and fixed is mentioned. In addition, it is preferable that a mixture of chitin nanofibers and cellulose nanofabrics is fixed on the fiber surface, and then a small amount of cellulose nanofibers having a long fiber length is further adhered thereon to improve washing durability. It is also preferable that a mixture of chitin nanofibers and cellulose nanofibers is fixed on the fiber surface, and then chitin nanofibers are further laminated thereon.
Thus, laminating different nanofibers or laminating a mixture of different nanofibers is an effective method for enhancing the adhesion in the present invention.

The present invention is characterized in that nanofibers are fixed in a network form on the surface of a structure made of cellulose fibers, synthetic fibers, protein fibers, and the like. In this case, it is more preferable that the nanofibers are directly fixed to the surface of the fiber structure.
In the present specification, the phrase “directly adhered” means a state in which nanofibers are present on the surface of cellulose fibers, synthetic fibers, protein fibers, etc. for a long time without using a binder resin, a crosslinking agent, or the like. means.
In the present invention, it is possible to use a small amount of a binder or a cross-linking agent. In that case, the binder or cross-linking agent is not allowed to act directly on the main nanofiber side having functional effects such as antibacterial properties. In order to maintain the effects such as antibacterial properties, it is preferable to increase the adhesion on the main nanofiber side having a functional effect indirectly by partially using a binder that does not become hard in a small amount on the nanofiber side.
For example, in the case of the mixed form of chitin nanofiber and cellulose nanofiber described above, only a small amount of blocked isocyanate is mixed as a binder that does not become hard only on the cellulose nanofiber side, and it is fixed and strengthened in a partial dot shape. This is a preferred embodiment because it can indirectly increase the adhesion on the chitin nanofiber side.

  As another aspect of the embodiment of the present invention, a solution in which nanofibers having specific functional groups having a width of 4 to 100 nm and a length of 100 to 2000 nm are dispersed in an acidic solution adjusted to pH 3.5 to 5.0 is provided. In addition, there may be mentioned a step in which the nanofibers are adhered by spraying onto the fiber surface made of cellulose fiber or synthetic fiber with a spraying device having a size per droplet of 20 μm or less. Examples include a step of immersing a synthetic fiber or protein fiber in the dispersion solution at a temperature of 25 to 80 ° C. for 15 to 45 minutes, allowing the nanofibers to adhere, and then drying gradually.

In the embodiment of the present invention, when the chitin nanofibers are fixed on the fiber in a network form, it is preferable to isolate and disperse each chitin nanofiber as a pretreatment.
As the method, for example, chitin nanofibers are dispersed in an acidic aqueous solution adjusted to pH 3.5 to 5.0, and ultrasonic irradiation is performed to isolate and disperse each chitin nanofiber one by one. There is a method of increasing the zeta potential to the positive side.
At this time, any acid can be used in the adjustment of the acidic aqueous solution having a pH of 3.5 to 5.0, but the oxycarboxylic acid is used without agglomeration of chitin nanofibers when irradiated with ultrasonic waves. It is preferable in that it can be easily separated one by one and the dispersibility in the aqueous solution can be easily improved, and the zeta potential of the aqueous dispersion can be increased to the plus side. The oxycarboxylic acid means an organic compound having a carboxyl group and a hydroxyl group in one molecule, and is preferable in that the pH can be easily controlled with a small amount of lactic acid, malic acid, tartaric acid and the like.
The pH of the aqueous solution is preferably adjusted to 3.5 to 5.5. When the pH of the aqueous solution is in the range of 3.5 to 5.5, the zeta potential of the chitin nanofiber dispersed aqueous solution can be increased to +40 to 100 mV after ultrasonic irradiation, and the dispersion stability of the chitin nanofiber is good. It becomes.
The frequency of ultrasonic waves in the ultrasonic treatment is preferably 10 to 200 kHz. Within this range, the chitin nanofibers having a width of 4 to 100 nm and a length of 100 to 2000 nm are separated into individual chitin nanofibers to increase the dispersion stability, and also to fix the zeta potential of the dispersion solution to +40 to 100 mV. Preferred above. Moreover, since the specific surface area of a chitin nanofiber can be raised to 150 m < ² > / g or more, it is preferable. If the frequency is less than 10 kHz, cavitation is strongly generated, and it is not preferable in that the separation stability of each one is deteriorated. On the other hand, if it exceeds 200 kHz, the cavitation effect is reduced, and the zeta potential of the dispersion is +40 mV or more. It is not preferable in that it cannot be increased. The ultrasonic treatment can be performed using an apparatus such as an ultrasonic homogenizer, an ultrasonic disperser, an ultrasonic cleaner, or the like.
The conditions for controlling the dispersibility of chitin nanofibers and the zeta potential of the dispersion solution by ultrasonic treatment include the concentration of chitin nanofibers, the treatment temperature, the time, and the like.
The concentration of chitin nanofibers immersed in an acidic aqueous solution having a pH of 3.5 to 5.0 is preferably 0.01 to 1.0% by mass, and more preferably 0.02 to 0.5% by mass.
The treatment temperature is preferably 25 to 50 ° C., and the treatment time is preferably 20 to 120 minutes, more preferably 20 to 60 minutes.
Moreover, when performing ultrasonic treatment, it is preferable to perform the treatment in a closed system from the viewpoint of improving the dispersion stability of chitin nanofibers.
If an aqueous dispersion is to be prepared using a normal stirrer or the like, the dispersibility and dispersion stability of chitin nanofibers are poor, and the zeta potential is +40 mV or less. If ultrasonic treatment is performed under the preferable conditions as described above, chitin nanofibers can be dispersed one by one, and the zeta potential of the dispersion can be increased to +40 to 100 mV. On the other hand, since the zeta potential on the fiber surface is usually −30 to 60 mV, it is possible to firmly adhere the network to the fiber surface without using a resin binder.
In addition, the zeta potential of the chitin nanofiber aqueous dispersion after ultrasonication can be measured using a zeta potentiometer.

In the present embodiment, the method of directly applying the chitin nanofiber aqueous dispersion dispersed in the acidic solution to the fiber surface of the fabric is not particularly limited, but for example, the size of the droplets per droplet Is a method of spraying directly onto the fabric surface using a spraying (coating) device having a diameter of 20 μm or less, preferably 15 μm or less, more preferably 10 μm or less, and reducing the amount of water per drop. It is preferable at the point which can be made to adhere to a mesh shape efficiently. If the size of the droplets per drop exceeds 20 μm, the amount of water instantaneously formed on the fiber surface increases, and it is difficult for the nanofibers to form a uniform network and the washing durability is also unfavorable.
In the present embodiment, the spray device is not particularly limited, and a two-fluid nozzle, an electrostatic spray device, and the like can be preferably used. The shape of the nozzle, the pressure during application, and the flow rate are preferably adjusted so that the size of the droplet per droplet is 20 μm or less. Further, the spray pattern may be either a mountain distribution or a uniform distribution.
The spraying process can also be performed after dyeing the fibers.

Further, a shape in which the nanofibers in the dispersion have a thickness of 20 to 80 nm and a length of 300 to 800 nm also contributes to the nanofibers adhering in a network shape. When the thickness and length of the nanofiber are out of the above range, it is difficult to form a network.
The concentration of chitin nanofibers contained in the aqueous dispersion is preferably 0.01 to 1.0% by mass, more preferably 0.02 to 0.8% by mass. If the content concentration is less than 0.01% by mass, the desired antibacterial performance cannot be obtained. On the other hand, if it exceeds 1.0% by mass, it is not preferable in that it is difficult to obtain a supple texture.

Further, a method of directly applying an aqueous dispersion of chitin nanofibers dispersed in an acidic solution to the fiber surface of a fabric made of synthetic fiber or protein fiber is economical and efficient in industrial production, and is also suitable for treatment by a dipping method. As a method. The dipping treatment can also be performed after the fibers are dyed.
A characteristic of applying chitin nanofibers to the fiber surface by the dipping method is that a synthetic fiber cloth or the like is immersed in an aqueous dispersion solution of chitin nanofibers after ultrasonic treatment, and the specific surface area is 150 m ^{2 on the} fiber surface. / G or more of chitin nanofibers is directly attached in a network form.
The pH of the aqueous dispersion is adjusted to 3.5 to 5.0, the bath ratio is 1:10 to 30, the treatment temperature is 25 to 80 ° C., and the treatment time is 15 to 45 minutes. It is preferable because the fibers are easily attached to the surface of the synthetic fiber in a dispersed state in the form of a mesh, and the washing durability is increased by attaching the fibers to the mesh. At this time, the treatment temperature is important. When the treatment temperature is less than 25 ° C. or more than 80 ° C., the adhesion of chitin nanofibers is poor and the washing durability is also poor. When the pH of the processing liquid is 3.5 or more, the zeta potential of the chitin nanofiber aqueous dispersion is not lowered and the dispersibility of the chitin nanofiber is maintained and aggregation is difficult to occur. It is preferable because it improves the durability and washing durability. Moreover, since it exists in the tendency for the adhesiveness of chitin nanofiber to improve when the pH of a process liquid is 5.0 or less, it is preferable.

In the present embodiment, since a solution in which chitin nanofibers are uniformly dispersed is used, the chitin nanofibers are fixed to the fiber surface of the fabric made of cellulose fiber, synthetic fiber, or protein fiber so as to be entangled in a network. Even when no resin is used, the washing durability of chitin nanofibers can be obtained. As described above, it is possible to partially use the binder resin under limited conditions.
Moreover, since it is made to adhere to the fiber surface in a mesh shape, an overwhelmingly high antibacterial effect can be obtained as compared with the conventional kneading method.

In the present invention, the shape, the number, and the number of crossings of the nanofibers adhering to the surface of the fiber structure composed of cellulose fiber, synthetic fiber, and protein fiber can be observed with an electron microscope, and within a fabric surface area of 1 μm ² In addition, it can be confirmed that 25 or more of those having a width of 4 to 100 nm and a length of 100 to 2000 nm are attached in a mesh shape.
Moreover, the component of the nanofiber adhering to the fiber surface in a mesh shape can be analyzed by TOF-SIMS. For example, in the case of chitin nanofibers, mass specific to components such as C ₄ H ₆ NO ₂ (m / z = 100) as negative ions and C ₇ H ₈ NO ₂ (m / z = 138) as positive ions It can be identified from the spectrum. FIG. 1 shows a negative ion spectrum of Example 1 as an example of TOF-SIMS analysis.
The ratio of the nanofibers occupying the surface of the fiber structure can be clarified by a combined analysis of TOF-SIMS and XPS.
In the present invention, when a plurality of cellulose fibers, synthetic fibers, and protein fibers are mixed and exposed on the fabric surface, the nanofiber adhesion state may differ depending on the fiber type. It is preferable that the adhesion state of each fiber type surface on the fabric surface is the above-mentioned shape.
Any condition can be applied to the dyeing of the fabric comprising the cellulose fiber or synthetic fiber of the present invention as long as it is a commonly practiced condition. Moreover, it does not specifically limit as a finishing process method of dyeing | staining fabric, What is necessary is just to select suitably according to a fabric characteristic.

In order to feel comfortable when sweating while wearing clothes, it is necessary for the fabric to have the ability to absorb moisture. Remains uncomfortable without being resolved. In order to eliminate the sticky feeling, it is necessary to quickly diffuse the absorbed water. In the present embodiment, since the nanofibers are directly attached to the fiber surface in a mesh shape, ultrafine undulations can be formed on the fiber surface, and the force of quickly diffusing moisture is exhibited by the increase of the undulations and surface area. The comfort when sweating when worn can be expressed by the water drop disappearance time and the water absorption diffusion area. With respect to the relationship between the water drop disappearance time, the water absorption diffusion and the comfort, the water drop disappearance time is 2 seconds or less, preferably 1 second or less, and the water absorption diffusion area is 8 cm ² or more, preferably 10 cm ² or more. In the fabric of this embodiment, the water drop disappearance time is 1 second or less, the water absorption and diffusion area is 11 cm ^2, and when used in skin clothing, it has a supple texture, so it feels good and sweats. Comfortable clothing can be obtained without sticking to the skin.

The fiber structure according to the present invention thus obtained has excellent antibacterial performance as defined in the certification standard established by the Textile Products Sanitary Processing Council (SEK). Specifically, the bacteriostatic activity value in Staphylococcus aureus to be postoperatively is 2.2 or more, preferably 2.5 or more.
The antibacterial fabric of this embodiment is characterized by excellent antibacterial performance in the above test even after repeated washing. Specifically, the antibacterial performance can be maintained even in a fabric after 20 times of washing according to JIS-L-0217-103.
The antibacterial fibrous fabric of this embodiment is excellent in water absorption performance in addition to the above antibacterial performance. Specifically, the water drop disappearance time after 20 washings is 2 seconds or less, and the water absorption diffusion area is 8 cm ² or more. It is a fabric product with high commercial value.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention should not be limited to these examples.
The characteristic value measurement method used in the examples and the like will be described below.
(1) Evaluation of antibacterial properties The antibacterial properties were evaluated in accordance with the unified test method of the Textile Products Hygiene Processing Council (SEK). After sterilization, dry specimens in a clean bench (0.4 g square test piece with a side of about 18 mm) were sterilized with high-pressure steam in advance and ice-cooled with 1/20 concentration nutrient broth. Inoculate 0.2 ml of the test bacteria suspension adjusted to 1 + 0.3) × 10 ⁵ cells / ml so that the entire specimen is evenly immersed, and tighten the sterilized cap. This was cultured at 37 ± 1 ° C. for 18 hours, and the number of viable bacteria after the culture was measured.
There are two types of specimens: a standard cloth (cloth specified in the processing effect evaluation test manual for antibacterial and deodorant processed products) and a processed cloth, and Staphylococcus aureus ATCC 6538P is used as the test bacteria. The following bacteriostatic activity values, which are indicators of the above, were calculated, and those having a bacteriostatic activity value of 2.2 or more were judged to be antibacterial.
Bacteriostatic activity value: LogB-LogC
However, the test establishment condition (LogB-LogA)> 1.5 shall be satisfied. A: Average number of bacteria recovered immediately after inoculation with standard cloth B: Average number of bacteria after 18 hours of culture of standard cloth C: Test Average number of bacteria after 18 hours of culture

(2) Nanofiber adhesion state on fiber surface Using a scanning electron microscope (manufactured by Hitachi, Model S-3500N), the surface of the fiber structure of the sample was magnified 50,000 times and observed. Nanofibers present on the fiber surface area of 1 μm ² of the sample fabric as compared with the scale gauge are photographed by selecting 10 sites where the nanofiber adhesion state is judged to be close to the average state of the entire sample. The width, length, number, and number of entanglements were measured, and an average value of 8 points was obtained by omitting the upper and lower values of each value.
In addition, the number of entanglements here shows the number of the intersections of nanofibers and nanofibers.
In a sample in which a plurality of fiber types are exposed on the surface, the adhesion state on each fiber type surface was measured individually.

(3) Identification of chitin nanofibers and detection of surface occupancy value Surface analysis of the fiber structure of the sample was performed using a surface analyzer TOF-SIMS (manufactured by ULVAC-PHI, nanoTOF). Chitin was identified by detection of C ₄ H ₆ NO ₂ (m / z = 100) from the negative ion mass spectrum. In addition, the normalized strength obtained by normalizing the detected intensity of C ₄ H ₆ NO ₂ (m / z = 100) with the detected intensity of general organic-derived negative ions C ₂ H is used as the surface of the fiber structure. The surface occupancy value of chitin in
<Measurement conditions>
Primary ion Bi ++, acceleration voltage 30 kV, ion current about 0.1 nA (DC conversion)
Analysis area 500μm × 500μm, negative detection ion

(4) Washing conditions According to JIS L-0217 103 method, it implemented 20 times. As a detergent, Kao Attack 1 g / L was used.

(5) Water drop disappearance time The water drop disappearance time of the processed product was evaluated according to the JIS-L-1097 dropping method. Measurement was performed 5 times for each sample after 20 washings, and the average water droplet disappearance time was determined. At this time, the average amount of one water droplet was 0.039 ml.

(6) Water-absorbing diffusion area The fabric is attached to a round frame for embroidery with a diameter of 15 cm, and 0.1 ml of a water-soluble blue dye (containing 0.005 wt% of CI Acid Blue 62) is dropped on the fabric surface for 3 minutes. The water-absorbing diffusion area that spreads after wetting
Water absorption diffusion area (cm ² ) = [vertical diameter (cm) × horizontal diameter (cm)] × π ÷ 4
Determined by
Measurement was performed 5 times for each sample, and the average water absorption and diffusion area was determined.

(7) Texture evaluation The fabric after 20 washings of the processed product was relatively evaluated according to the following evaluation criteria according to the feel of the inspector (30 persons).
○: A soft and supple texture △: A feeling of softness and a feeling of suppleness are slightly inferior ×: Hard and a feeling of softness is not good

[Examples 1, 2, 3]
<Preparation of chitin nanofiber aqueous dispersion>
A chitin nanofiber (trade name: Vinfis (model: SFo-20010), concentration: 10 wt%) manufactured by Sugino Machine Co., Ltd. was added to an aqueous solution prepared at pH 4 with malic acid. A predetermined amount was dissolved while stirring. In Example 2, the fiber was dissolved in a separately prepared pH 4 aqueous solution with stirring so that the concentration of the chitin nanofibers was 0.2% by mass. Further, in Example 3, the fiber was dissolved in an aqueous solution having a pH of 4 prepared separately while stirring so that the concentration of the chitin nanofibers was 0.4 mass%.
Next, as a condition common to Examples 1 to 3, this aqueous solution was irradiated in a sealed state for 45 minutes while heating to 30 ° C. at a high frequency output of 80 W and a transmission frequency of 40 kHz using an ultrasonic device. A solution in which the nanofibers were not aggregated was prepared. Here, even after the dispersion solution was allowed to stand at room temperature for two days and nights, there was no aggregation or precipitation of chitin nanofibers in all the solutions, and it was confirmed that the dispersion stability in an aqueous solution was high. The zeta potential of the dispersion solution is +56.4 mV when the concentration is 0.1% by mass (Example 1), +62.6 mV when the concentration is 0.2% by mass (Example 2), and 0.4% by mass. % (Example 3), it was +63.8 mV. Moreover, the specific surface area of the chitin nanofibers was 240 m ² / g.

<Preparation of dyed fabric>
Using a 84-dtex / 45f cupra (Asahi Kasei Co., Ltd., Bemberg (registered trademark)) and 33 dtex polyurethane fiber (Asahi Kasei Co., Ltd., Leuka (registered trademark)), a bare tengu-maru knitted fabric at 36 gauge in a conventional manner. Produced. The mixing ratio of the cupra fibers at this time was 87 wt%.
Subsequently, after pre-wetting at 70 ° C. in an expanded state, it was pre-set at 185 ° C. and dyed under the following conditions.
<Dyeing conditions>
Reactive dye: Remazole Brilliant Red BB: 0.15% omf
Sodium carbonate: 10 g / liter Sodium sulfate: 20 g / liter Auxiliary agent: Imacol C2GL (softener in bath): 4 g / liter Bath ratio: 1:20
Dyeing temperature, time: 60 ° C., 40 minutes After dyeing, hot water washing and water washing were repeated at 90 ° C., followed by dehydration and drying.
The zeta potential on the surface of the dyed fabric was -38.5 mV.

<Adhesion of chitin nanofibers to the fiber surface>
Next, the chitin nanofiber concentration prepared in the above was 0.1% by mass (Example 1), 0.2% by mass (Example 2), and 0.4% by mass (Example 3), respectively. Using a two-fluid nozzle (AM-12 manufactured by Atmax Co., Ltd.), adjusting the flow rate at a distance of 100 mm from the nozzle to the fabric surface and a nozzle pressure of 0.4 MPa, the size of the droplets shown in Table 1 below It adjusted so that it might become, and it sprayed on the dyeing | staining fabric surface. After spraying, it was dried at 90 ° C., adjusted to have a basis weight of 120 g / m ^2, and finished by heat treatment at 130 ° C.
Table 1 below shows the evaluation results of the shape, number, number of intersections, antibacterial performance, texture, and water absorption of chitin nanofibers fixed on the fiber surface of the obtained dyed fabric. From the results of Table 1, it can be seen that the fabrics obtained in Examples 1, 2, and 3 are excellent in antibacterial performance and water absorption performance, have a supple texture, and have high commercial value.
FIG. 1 shows a negative ion spectrum of Example 1 as an example of TOF-SIMS analysis. FIG. 1A shows a negative ion spectrum with an m / z of 0 to 200, and FIG. 1B shows a spectrum with an m / z of 200 to 1000.
FIG. 2 shows a scanning electron micrograph of Example 1. FIG. 2A shows a case where the magnification is 20,000 times, and FIG. 2B shows a case where the magnification is 50,000 times.

[Comparative Examples 1, 2, 3]
The chitin nanofiber aqueous dispersion obtained in Example 1 was adjusted with a two-fluid nozzle in the same manner as in Example 1 with the nozzle pressure and flow rate adjusted to the particle size shown in Table 1 below. After spraying and drying at 90 ° C., it was finished by heat treatment at 130 ° C. so as to have the same basis weight as in Example 1.
The evaluation results of the antibacterial performance, texture, and water absorption performance of the obtained dyed fabric are shown in Table 1 below.
From the results in Table 1, the dyed fabrics obtained in Examples 1 to 3 of the present invention are superior in antibacterial performance and water absorption performance as compared to the fabrics obtained in Comparative Examples 1, 2, and 3, and also in the texture. It turns out that it is an excellent and high commercial value dyed fabric.

[Example 4]
A nylon 6-fiber 78 dtex / 68f POY is false twisted at 185 ° C. by a conventional method, leaving an untwisted portion, inserting a 56 dtex / 45 f cupra into the interlace, interlaced, 110 dtex / 113 f A composite yarn was obtained.
Using the obtained composite yarn and 33 dtex polyurethane fiber, a bare knitted fabric was produced by a conventional method at 28 gauge. The mixing ratio of cellulose fibers in the knitted fabric was 48%, the mixing ratio of nylon fibers was 42%, and the mixing ratio of polyurethane fibers was 10%.
Subsequently, after scouring at 80 ° C., a preset was performed at 185 ° C., and dyeing was performed under the following conditions:
<Dyeing conditions>
Reactive dye; Kayatheron React Red CN-3B: 0.1% omf
Acid dye; Nairosan Red N-GZS: 0.1% omf
Leveling agent: Liogen KSE 2% omf
Kayak buffer P-7: 2 g / liter Salt glass: 20 g / liter Bath ratio: 1:20
Dyeing temperature and time: 100 ° C., 30 minutes After dyeing, the mixture was repeated twice at 80 ° C. in the order of hot water washing and water washing, followed by dehydration and drying. The zeta potential on the surface of the dyed fabric was -42.5 mV.
<Adhesion of chitin nanofibers to fiber fabric>
A two-fluid nozzle (AM-12 manufactured by Atmax) was used for the aqueous dispersion of chitin nanofibers having a concentration of 0.2% by mass produced in Example 2, and the nozzle pressure was set to 100 mm from the nozzle to the surface of the dyed fabric. At 4 MPa, the flow rate was adjusted so that the size of the droplets was 7.9 μm, and sprayed directly onto the surface of the dyed fabric. After spraying, it was dried at 90 ° C., adjusted to have a basis weight of 140 g / m ^2, and finished by heat treatment at 130 ° C.
Table 1 below shows the evaluation results of chitin nanofibers adhered to the fiber surface of the obtained dyed fabric, antibacterial performance, texture and water absorption. From the results shown in Table 1, it can be seen that the fabric obtained in Example 4 has excellent antibacterial performance and water absorption performance, has a supple texture, and has a high commercial value.

[Comparative Example 4]
Spraying the aqueous dispersion of chitin nanofibers with a concentration of 0.2% by mass produced in Example 2 with a two-fluid nozzle, adjusting the nozzle pressure and flow rate so that the size of the droplets is 33.6 μm, and spraying Then, after drying at 90 ° C., it was finished by heat treatment at 130 ° C. so as to have the same basis weight as in Example 4.
The evaluation results of the antibacterial performance, texture, and water absorption performance of the obtained dyed fabric are shown in Table 1 below.

[Example 5]
A yarn of polyester fiber 80 dtex / 48f is false twisted at 190 ° C. by a conventional method, leaving an untwisted portion, inserting a 56 dtex / 45 f cupra during the processing step, interlaced, and 108 dtex / 93 f A composite yarn was obtained.
Using the obtained composite yarn and 22 dtex polyurethane fiber, a bare tentacle knitted fabric was produced by a conventional method at 28 gauge. In this knitted fabric, the mixing ratio of cellulose fibers was 49%, the mixing ratio of polyester fibers was 43%, and the mixing ratio of polyurethane fibers was 8%.
Subsequently, after scouring at 80 ° C., presetting was performed at 190 ° C., and dyeing was performed under the following conditions.
<Dyeing conditions>
Reactive dye; Kayatheron React Blue CN-BL: 0.1% omf
Acid dye; Kayalon polyester blue AQ-LE: 0.1% omf
Kayak buffer P-7: 2 g / liter Salt glass: 20 g / liter Bath ratio: 1:20
Dyeing temperature, time: 130 ° C., 30 minutes After dyeing, it was repeated twice in the order of washing with hot water and washing with water at 80 ° C., followed by dehydration and drying.
The zeta potential on the surface of the dyed fabric was -43.8 mV.
<Adhesion of chitin nanofibers to fiber fabric>
A two-fluid nozzle (AM-12 manufactured by Atmax) was used for the aqueous dispersion of chitin nanofibers having a concentration of 0.2% by mass produced in Example 2, and the nozzle pressure was set to 100 mm from the nozzle to the surface of the dyed fabric. At 4 MPa, the flow rate was adjusted so that the size of the droplets was 7.9 μm, and sprayed directly onto the surface of the dyed fabric. After spraying, it was dried at 90 ° C., adjusted to have a basis weight of 135 g / m ^2, and finished by heat treatment at 130 ° C.
Table 1 below shows the evaluation results of chitin nanofibers adhered to the fiber surface of the obtained dyed fabric, antibacterial performance, texture and water absorption. From the results shown in Table 1, it can be seen that the fabric obtained in Example 5 has excellent antibacterial performance and water absorption performance, has a supple texture, and has a high commercial value.

[Comparative Example 5]
In the same manner as in Example 5, the aqueous dispersion of chitin nanofibers having a concentration of 0.2% by mass produced in Example 2 was subjected to nozzle pressure and flow rate so that the size of the droplets would be 33.6 μm. Was directly sprayed, dried at 90 ° C., and then heat treated at 130 ° C. to finish with a basis weight equivalent to that of Example 5.
The evaluation results of the antibacterial performance, texture, and water absorption performance of the obtained dyed fabric are shown in Table 1 below.

[Example 6]
Nylon 6 fiber 78dtex / 68f POY was false twisted at 180 ° C. by a conventional method to obtain a 56 dtex / 68f false twisted yarn.
Using the obtained false twisted yarn and 33 dtex polyurethane fiber, a bare knitted fabric was produced by a conventional method at 28 gauge. In this knitted fabric, the mixture ratio of nylon fibers was 90%, and the mixture ratio of polyurethane fibers was 10%.
Subsequently, after scouring at 80 ° C., presetting was performed at 190 ° C., and dyeing was performed under the following conditions.
<Dyeing conditions>
Acid dye; Nairosan Red N-GZS: 0.1% omf
Leveling agent: Liogen KSE 2% omf
pH: 4.5 (acetic acid adjustment)
Bath ratio: 1:25
Dyeing temperature and time: 100 ° C., 30 minutes After dyeing, the mixture was repeated twice at 80 ° C. in the order of hot water washing and water washing, followed by dehydration and drying.
The zeta potential on the surface of the dyed fabric was −40.5 mV.
<Applying chitin nanofibers to fiber fabric>
The dyed fabric was immersed in a dispersion solution prepared in the same manner as in Example 1 except that the concentration of chitin nanofibers produced in Example 1 was 0.05% by mass (bath ratio 1:10), and 30 ° C. at 30 ° C. Treated for minutes. After the treatment, it was dehydrated, adjusted to have a basis weight of 120 g / m ^2, and finished by a heat treatment at 130 ° C.
Table 1 below shows the evaluation results of chitin nanofibers adhered to the fiber surface of the obtained dyed fabric, antibacterial performance, texture and water absorption. From the results shown in Table 1, it can be seen that the fabric obtained in Example 6 has excellent antibacterial performance and water absorption performance, has a supple texture, and has a high commercial value.

[Example 7]
A smooth knitted fabric was produced by using a 28-gauge polyester fiber 84 dtex / 48f having a W-shaped cross section.
Subsequently, after scouring at 80 ° C., presetting was performed at 190 ° C., and dyeing was performed under the following conditions.
<Dyeing conditions>
Disperse dye: C.I. I. Disperse Blue 167 0.2% omf
Dispersant: Nikkasan Salt RM-340 0.5 g / liter Acetic acid: 0.5 g / liter Sodium acetate: 1 g / liter Bath ratio: 1:20
Dyeing temperature, time: 130 ° C., 30 minutes After dyeing, it was dehydrated after repeating three times in the order of washing with hot water and washing with water at 80 ° C.
The zeta potential on the surface of the dyed fabric was −45.4 mV.
Next, in Example 1, the dyed fabric was immersed in a dispersion solution prepared in the same manner as in Example 1 except that the chitin nanofiber concentration was 0.05% by mass (bath ratio 1:10), and 50 ° C. For 30 minutes, and after the treatment, it was dehydrated, adjusted to have a basis weight of 120 g / m ^2, and finished by heat treatment at 130 ° C.
Table 1 below shows the evaluation results of chitin nanofibers attached to the fiber surface of the dyed fabric, antibacterial performance, texture, and water absorption. From the results of Table 1, it can be seen that the fabric obtained in Example 7 is a dyed fabric having excellent antibacterial performance and water absorption performance, a supple texture, and a high commercial value.

[Comparative Example 6]
1.4T x 33mm cupra short fiber (Benberg (registered trademark) manufactured by Asahi Kasei Co., Ltd.) is mixed with 1% by weight chitin nanofiber and spun, and then spun 50 /-(cotton count) in a conventional manner. ) Using this 50 / − yarn and 33 dtex polyurethane fiber (Roika (registered trademark) manufactured by Asahi Kasei Co., Ltd.), a bare tengumaru knitted fabric was produced by 28 gauge according to a conventional method. The mixing ratio of the cupra short fibers at this time was 91 wt%.
Subsequently, after pre-wetting at 70 ° C. in an expanded state, it was pre-set at 185 ° C. and dyed under the following conditions.
<Dyeing conditions>
Reactive dye: Remazole Brilliant Red BB: 0.15% omf
Sodium carbonate: 10 g / liter Sodium sulfate: 20 g / liter Auxiliary agent: Imacol C2GL (softener in bath): 4 g / liter Bath ratio: 1:20
Dyeing temperature, time: 60 ° C., 40 minutes After dyeing, hot water washing and water washing were repeated at 90 ° C., followed by dehydration and drying.
The zeta potential on the surface of the dyed fabric was -38.5 mV.
Table 1 shows the evaluation results of the antibacterial performance, texture, and water absorption performance of the obtained dyed fabric.

  The fiber structure made of cellulose fiber or synthetic fiber with nanofibers fixed to the fiber surface of the present invention is excellent in antibacterial performance and water-absorbing and diffusing performance, has a soft and supple texture, and is excellent in wearing feeling. Therefore, it can be suitably used in various applications that come into contact with the skin, such as the inner field, sports clothing field, medical field, and the like.

Claims (4)

There are 25 or more nanofibers having a width of 4 to 100 nm and a length of 100 to 2000 nm per surface area of 1 μm ^{2 of the} structure on the surface of a fiber structure made of cellulose fiber, synthetic fiber or protein fiber. A fiber structure characterized by being fixed to the surface of the fiber.   The fiber structure according to claim 1, wherein the entanglement number of the plurality of nanofibers is 20 or more.   The fiber structure according to claim 1, wherein the nanofiber is made of a polysaccharide.   The fiber structure according to claim 2, wherein the nanofiber is made of a polysaccharide having an acetylamino group.