Fiber processing agent, fiber processing method, and antiviral fiber

Abstract

To provide a fiber processing agent which is harmless to humans and animals and can impart antiviral function and which also improves texture.SOLUTION: A fiber processing method includes attaching a fiber processing agent made by mixing tannin, sericin, fibroin, and water or ethanol aqueous solution to a fiber product, followed by drying.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a fiber processing agent that can impart antiviral function to fibers by surface treating the fibers and further makes the texture of the fibers soft and pleasant to the touch. [Background technology]

[0002] The recent spread of infectious diseases caused by new viruses has presented us with a new challenge. It will take at least a year for an effective vaccine to be developed, and it has become clear that until then, we must survive by taking defensive measures such as wearing masks, washing our hands, and using disinfectants such as ethanol.

[0003] As a defensive measure to prevent the spread of infection, we are considering applying antiviral treatment to the various textile products around us. If we could impart antiviral properties to the many textile products around us, such as clothing, masks, bedding, curtains, and car seats, it would have a significant impact on social activity, such as slowing the spread of infection, reducing strain on medical institutions, and securing time for the development of vaccines. Because textiles generally have a large surface area, it is possible to impart various functionalities through surface treatment.

[0004] Cationic quaternary ammonium ions, as shown in Patent Document 1, are often used to impart antiviral properties to textiles. However, quaternary ammonium ions are cationic surfactants, which are far more irritating and toxic to the skin than the anionic surfactants used in ordinary detergents. For this reason, they are not recommended for use on masks, underwear, and other areas that come into direct contact with the skin. Furthermore, they are limited to use at low concentrations, which requires tedious work such as concentration management. Furthermore, the risk of accidental ingestion by elderly people with dementia and infants cannot be eliminated. We have always wanted to develop a textile processing agent that does not require meticulous concentration management and is safe even if accidentally ingested.

[0005] Persimmon tannin, or its main component, has been known to be effective against mold and bacteria and has been used in paints and to strengthen umbrellas and fishing nets. Tannin is also known to have anti-inflammatory properties. Patent Document 2 shows that oyster extract containing tannins is highly effective against norovirus. However, when oyster extract is applied to the surface of textiles for dyeing or other processing, the textiles become hard and uncomfortable to the touch, making it unsuitable for use in underwear and other garments that come into direct contact with the skin.

[0006] We actually purchased a commercially available persimmon tannin silk mask and checked its texture. As a result, it was found to be stiff and uneasy to wear, making it unsuitable for a mask that will be in contact with the skin for long periods of time. Furthermore, our research has shown that dyeing the silk surface with tannin does not provide antiviral effects. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-098976 [Patent Document 2] Re-tabled publication No. 2008 / 153077 Summary of the Invention [Problem to be solved by the invention]

[0008] The object of the present invention is to provide a textile finishing agent that is safer than quaternary ammonium ions, imparts a sustained antiviral effect to textile products, and improves the softness and feel of textiles. This finishing agent is based on tannin and is easy to apply to textiles under certain conditions. [Means for solving the problem]

[0009] The inventors aimed to develop a textile processing agent that can provide long-lasting protection to textile products by utilizing the strong antiviral properties of tannin and its affinity with proteins. This research succeeded in establishing a manufacturing method that improves the softness and feel of fabrics while maintaining the antiviral effect on textiles by mixing tannin with sericin and fibroin in a specific ratio.

[0010] The present application relates to the following inventions. The fiber processing agent is characterized by comprising at least one of tannin, sericin, and fibroin, and at least one of water and alcohol.

[0011] The fiber processing agent is characterized in that, when the total is taken as 100% by mass, the agent contains 0.1 to 5% by mass of tannin, 0.1 to 0.4% by mass of sericin, 0.01 to 1.0% by mass of fibroin, and the remainder being water or alcohol.

[0012] Furthermore, in the fiber processing agent, the alcohol is ethanol.

[0013] As another invention, the present invention provides a method for processing fibers to impart antiviral functionality, comprising the steps of: adhering the fiber-processing agent to fibers by immersing the fibers in the fiber-processing agent or spraying the fiber-processing agent onto the fibers; and drying the fibers to which the fiber-processing agent has been adhered.

[0014] Furthermore, the present invention provides a fiber processing method for imparting the antiviral function, characterized in that the fiber is processed in advance with Lipidure.

[0015] Yet another aspect of the present invention is an antiviral fiber having at least one of tannin and sericin or fibroin attached thereto.

[0016] The fiber is an antiviral fiber that is at least one type selected from the group consisting of natural fibers, semi-synthetic fibers, and synthetic fibers.

[0017] Furthermore, the antiviral fiber is at least one selected from the group consisting of cotton, linen, silk, wool, cellulose, polyester, nylon, polyethylene terephthalate, polyethylene, polypropylene, acrylic, rayon, tetron, and cupra. [Effects of the Invention]

[0018] The fiber processing agent of the present invention can easily impart antiviral properties to fibers to be processed while maintaining a soft texture by adhering the fiber processing agent to the fibers. The processed fibers treated with the fiber processing agent can inactivate viruses attached to the surface and reduce infectivity. The fiber processing agent of the present invention can be suitably used to impart antiviral properties to general clothing such as underwear, socks, and blouses; bedding-related fibers such as futon covers and pillowcases; medical-related fibers such as bandages and gauze; toy-related fibers such as stuffed toys; and filters for air conditioners and air purifiers. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments of the present invention will be described. Note that the present invention is not limited to the following embodiments and implementations, and can be carried out with appropriate modifications.

[0020] One aspect of the present invention relates to a fiber processing agent comprising at least one of tannin, sericin, and fibroin, and at least one of water and alcohol. The present invention will be described in detail below.

[0021] In one embodiment, the fiber processing agent of the present invention comprises tannin, sericin, and fibroin dispersed in a mixed solvent of water and alcohol or a single solvent mainly composed of water or alcohol.

[0022] The tannin may be, for example, persimmon tannin obtained from the fruit of the persimmon tree (scientific name: Diospyros kaki), a plant of the Ebenaceae family, or tannin contained in tea leaves, wine, or Chinese gallnuts. Tannins have already been industrialized and are available at low cost, making it possible to reduce production costs and making them highly industrially applicable. The tannin of the present invention is not particularly limited, and industrially available tannins can be used as they are.

[0023] The sericin or fibroin used in the present invention is thought to act as an intermediary for attaching tannin to fibers and is an essential component for maintaining the softness of fibers. Sericin or fibroin can be used without any particular limitation as long as it has water-soluble properties. For example, sericin and fibroin extracted from silkworm cocoons or cocoon fluff can be used.

[0024] In the present invention, either sericin or fibroin may be used alone, but it is more preferable to use both sericin and fibroin.

[0025] The fiber processing agent of the present invention is prepared by dissolving tannin, sericin, and fibroin in water or alcohol. There are no particular limitations on the composition of the components of the fiber processing agent as long as tannin, sericin, and fibroin are dissolved. The contents of each component, based on 100 parts by mass of the total, are 0.1 to 5 parts by mass of tannin, 0.1 to 0.4 parts by mass of sericin, and 0.01 to 2.0 parts by mass of fibroin, with the remainder being water or alcohol.

[0026] If the tannin content is less than 0.1% by mass, the antiviral effect is lost, and if it exceeds 5% by mass, the dough becomes stiff and hard.

[0027] If the amount of sericin is less than 0.1% by mass, the moisturizing effect will be small, and if it exceeds 0.4 parts by mass, the moisturizing effect will not be improved and the cost will increase.

[0028] If the amount of fibroin is less than 0.01 mass %, the sponge effect is lost, and if the amount exceeds 2.0 mass parts, the sponge effect is not improved and the cost increases.

[0029] A more preferred content of each component is 1 to 3 parts by mass of tannin, 0.1 to 1.0 part by mass of sericin, 0.05 to 0.5 part by mass of fibroin, and the remainder being water or alcohol, with the alcohol content being 5 to 75 parts by mass.

[0030] The pH of such an aqueous solution of the fiber processing agent of the present invention is preferably set in the range of 3 or more and 6 or less.

[0031] The purpose of adding alcohol to the fiber processing agent of the present invention is to improve the dispersibility of each component of the mixed solution and for antiseptic purposes. The alcohol used for this purpose is preferably a water-soluble alcohol that is freely miscible with water, such as methanol, ethanol, isopropanol, ethylene glycol, propylene glycol, and glycerin. Ethanol, isopropanol, and ethylene glycol are preferred. When using alcohols, the concentration does not have any particular effect, but the amount added is preferably 5 to 75 parts by mass per 100 parts by mass of the fiber processing agent.

[0032] There are no particular limitations on the fiber materials that can be used as fibers to which antiviral functionality can be imparted, and they can be used for textile fabrics used in clothing, etc., nonwoven fabrics used in filters, etc. Fiber materials that can be imparted with antiviral functionality include cellulose fibers such as cotton, natural fibers such as silk, hemp, and wool, synthetic fibers such as polyester, nylon, polyethylene terephthalate, polyethylene, and polypropylene, and semi-synthetic fibers such as rayon, cupra, and tetron.

[0033] That is, the fiber processing agent of the present invention can be suitably used to impart antiviral functionality to general clothing such as underwear, socks, and blouses; bedding-related fibers such as futon covers and pillowcases; medical-related fibers such as bandages, gauze, and masks; toy-related fibers such as stuffed toys; and filters for air conditioners and air purifiers. [Example]

[0034] Example 1 The tannins used were derived from persimmon and gallnut. The sericin solution was prepared by extracting cocoons or cocoon fluff in a high-pressure vessel such as a pressure cooker at a bath ratio of 1:100 and a water temperature of 100-130°C for 1-2 hours. The fibroin solution was prepared by adding water and calcium chloride to the residue at a bath ratio of 1:100, extracting at a water temperature of 140-180°C for 1-2 hours, and then subjecting the solution to dialysis to remove the calcium chloride. 100 mL of each solution was prepared, mixed with 50 g of tannin powder, and water was added to make a total of 1000 mL.

[0035] The fabric was dyed in this solution at a bath ratio of 1:20, at 40°C, for 30 minutes while stirring. It was then dehydrated and dried. The fabric treated in this way was subjected to an antiviral test using the following method.

[0036] In this example, the initial concentrations of sericin and fibroin were 0.4% by mass and 2.0% by mass, respectively, and the optimal blend ratios of tannin, sericin, and fibroin were evaluated based on these concentrations. The test results showed that sericin was most effective in the range of 0.01 to 0.2% by mass, and fibroin in the range of 0.01 to 1.0% by mass, and it was confirmed that the feel of the fabric was most improved within these ranges.

[0037] Antiviral evaluation of fibers (test common to all examples) The antiviral effect of the treated fabric was evaluated using the TCID50 method, following the procedure below, with reference to JIS L 1922 "Testing method for antiviral activity of textile products."

[0038] (1) The processed fabric was cut into 20mm x 20mm pieces, stacked to a mass of 0.4g, and placed in a vial with a lid. Three test samples were prepared, and six blank samples were prepared by treating cotton JIS fastness white cloth in the same way. (2) The vial containing the dough was wrapped in aluminum foil with the lid separately, and the vial containing the sample was covered with aluminum foil, and both were sterilized in an autoclave (121°C, 20 minutes). After sterilization, the vial was immediately dried in a clean bench. After drying, the lid was replaced and the sample was kept clean until testing. (3) The virus used was influenza virus (PR8 strain) or feline calicivirus, and the initial infection concentration of the virus was 107TCID50 / mL. (4) 200 μL of the virus solution was dropped onto the sample, which was then absorbed, and the container was closed and left to stand for 2 hours at 25° C. Triplicate samples were used for each test. (5) The infectivity titer of the three blank samples was also measured immediately after the virus was added. The infectivity titer is the amount of virus that the test cells need to be exposed to in order to become infected. The purpose of this test is to confirm whether the infectivity of the virus is maintained immediately after addition and after being left to stand for two hours. In other words, it is to prove that the infectivity of the virus has not decreased even after two hours. If the difference in this infectivity titer decreases by one digit (90%) or more, the test is invalid. (6) Each sample was placed in 20 mL of SCDLP medium (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and stirred thoroughly to wash out any viruses adhering to the sample. (7) Using this virus washout solution as the stock solution, a 10-fold dilution series was prepared. 100 μL of the stock solution was taken and added to 900 μL of dilution solution to produce a 1 / 10 dilution solution. By repeating the same process, virus dilutions of 1 / 100, 1 / 1000, 1 / 10,000, etc. were prepared. A medium commonly used in virus testing (Opti-MEM I Reduced Serum Medium, hereafter referred to as growth medium) was used for dilution. (8) Unlike bacteria, viruses cannot replicate on their own, so they must infect cells and grow. In this study, we used MDCK cells (canine kidney-derived cells), which are commonly used in influenza virus testing. For feline calicivirus, we used CRFK cells (feline kidney-derived cells). Each cell type was cultured in a 96-well microplate before use. For influenza virus testing only, the cell surface was washed with 0.25% trypsin-containing growth medium (hereafter referred to as maintenance medium) before adding the virus dilution. Washing was performed twice, with 100 μL of maintenance medium added to each well. To prevent the cells from drying out, the second wash was performed immediately before adding each virus dilution. (9) 100 μL of each diluted solution was dropped into each well. The first 8 wells contained the virus washout stock solution, and the second well contained the 1 / 10 diluted solution. This was repeated for each diluted solution. (10) The microplate was covered and placed in a CO2 incubator at 33°C for 1 hour to allow the virus to infect the cells. (11) After standing for 1 hour, each virus dilution on the microplate was removed, and 100 μL of maintenance medium for influenza virus or growth medium for feline calicivirus was added to wash the cell surface. Then, 200 μL of maintenance medium or growth medium was added to each well, and the plate was cultured in a CO2 incubator at 33°C for 7 days. (12) On the 7th day of culture, the cells were observed under an inverted microscope, and the state of the cells in each well was recorded in a results table. (13) The state of the cells in each well was observed, and the virus infectivity titer was determined by the Behrens-Körber method.

[0039] As a result, the antiviral activity value of the fabric treated with the processing solution containing persimmon-derived tannin was 3.1. The value of the processing agent containing gallnut-derived tannin was 4.2. According to JIS L 1922 "Testing methods for antiviral activity of textile products," the antiviral activity value (Mv) is defined as effective when 3 > Mv ≥ 2, and as sufficiently effective when Mv ≥ 3. Therefore, the fabrics processed in this example were sufficiently effective in both cases.

[0040] Next, we attempted to quantify the feel of the fabric, but because no experimental method had been established, we resorted to sensory evaluation. When we surveyed people around the inventor about the feel of fabrics treated with processing agents containing silk solution and those without, 10 out of 10 people answered that they felt that the fabric treated with silk solution felt better against the skin, as shown in Table 1.

[0041] [Table 1]

[0042] Example 2 In Example 2, the fibers to be processed were pre-treated with Lipidure and then treated with the fiber processing agent of the present invention. Lipidure is a substance modeled after the phospholipids found in human cell membranes and tears, making it highly biocompatible and effective at improving moisture retention. In this example, fabrics were pre-treated with commercially available Lipidure at 3% OWF. OWF stands for "on the weight of fiber," meaning "per fiber weight." For example, 3% OWF means that 3% of the weight of the fibers to be dyed is used, meaning that 100g of fabric requires 3g of dye. The fabrics were then processed in the same manner as in Example 1. The results showed that the fabrics processed with Lipidure alone had an antiviral activity value of 0.4, while the processing solution containing gallnut-derived tannins had an antiviral activity value of 2.3, and the processing solution containing persimmon-derived tannins had an antiviral activity value of 3.8. Furthermore, the antiviral activity value for feline calicivirus, used as a norovirus surrogate, was 2.5. In this way, by dyeing the processed fabric with Lipidure in advance, the moisture retention can be increased, and further, antiviral processing can be performed using the fiber processing agent described in Example 1.

[0043] Example 3 In Example 3, mordanting using persimmon-derived tannin was investigated. Mordanting is a process performed to stabilize dyeing. Natural dyes, known as plant dyes, such as persimmon tannin, are unstable on their own, so a mordant can be used to stabilize them. Mordants are used that are insoluble in water, and metals such as aluminum and copper are typical. In this example, copper and aluminum mordanting were used. After dyeing with the processing agent prepared with persimmon-derived tannin in Example 1, the fabric was treated with 1% copper and 1% aluminum solutions in a bath ratio of 1:20 at room temperature, and then washed and finished. The results showed that the aluminum-mordanted fabric had an antiviral activity value of 4.1, and the copper-mordanted fabric also had an antiviral activity value of 4.1.

[0044] Example 4 Treatment was carried out by spraying using a sprayer or the like. 400 μL of a 63% by mass ethanol solution containing the persimmon-derived tannin shown in Example 1, sericin solution, and fibroin solution was sprayed onto the dried cotton fabric, which was then tested after drying. The result was an antiviral activity value of 3.9. Similarly, when 400 μL of a 63% ethanol solution containing only persimmon-derived tannin without the sericin solution or fibroin solution was sprayed onto the dried cotton fabric, the antiviral activity value was 3.6. This demonstrates that the antiviral effect is slightly improved by adding the sericin solution and fibroin solution.

[0045] (Comparative Example 1) In Comparative Example 1, the antiviral effect of fabric processed using a conventional method was examined. Previously, the inventors had applied Lipidure processing to fabric, then further processed it with sericin and fibroin solutions, and then dyed it with tannins such as persimmon-derived tannins. When fabric processed with Lipidure and then processed with persimmon tannin was tested, the antiviral effect was 2.0. Next, when fabric processed with Lipidure and then processed with sericin and fibroin solutions, and then processed with persimmon tannin, the antiviral effect was 0.6. The finding from Comparative Example 1 was that processing with tannin after silk processing inactivates the antiviral effect. In other words, antiviral processing was not possible using conventional processing methods.

[0046] Therefore, through diligent efforts and research, the inventors were able to invent a textile processing agent that does not lose its antiviral effect by mixing tannin with sericin and fibroin. [Industrial Applicability]

[0047] The present invention provides an antiviral fiber-treating agent that can impart antiviral properties to various textile products in a simple manner. Fabrics treated with the antiviral fiber-treating agent of the present invention have an antiviral activity value of 2.0 or higher, making it highly applicable industrially as a countermeasure against novel viral infections.

Claims

1. A fiber processing agent comprising at least one of tannin, sericin, and fibroin, and at least one of water and alcohol.

2. 2. The fiber processing agent according to claim 1, characterized in that, when the total is taken as 100% by mass, the agent contains 0.1 to 5% by mass of tannin, 0.01 to 0.2% by mass of sericin, 0.01 to 1.0% by mass of fibroin, and the remainder being water or alcohol.

3. 3. The fiber processing agent according to claim 1, wherein the alcohol is ethanol.

4. 10. A method for processing fibers using the fiber processing agent according to claim 1, comprising immersing the fiber processing agent in the fiber processing agent or spraying the fiber processing agent onto the fiber.

5. 5. The method for processing fibers to impart antiviral properties according to claim 4, wherein the fibers are pre-processed with Lipidure.

6. An antiviral fiber having at least one of tannin and sericin or fibroin attached thereto.

7. 7. The antiviral fiber according to claim 6, wherein the fiber is at least one selected from the group consisting of natural fibers, semi-synthetic fibers, and synthetic fibers.

8. 7. The antiviral fiber according to claim 6, wherein the fiber is at least one selected from the group consisting of cotton, linen, silk, wool, cellulose, polyester, nylon, polyethylene terephthalate, polyethylene, polypropylene, acrylic, rayon, tetron, and cupra.

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